Thermal Hydraulics System Requirements Specification

This template follows INL template TEM-135, "IT System Requirements Specification".

note

This document serves as an addendum to Framework System Requirements Specification and captures information for SRS specific to the Thermal Hydraulics module.

Introduction

System Purpose

The purpose of the MOOSE Thermal Hydraulics module is to provide capability for performing system-level thermal hydraulic simulations in MOOSE. This capability provides a convenient means of developing a system of connected components on multiple domains, focused primarily on low-fidelity (one-dimensional and two-dimensional) models. This allows large, complex systems, such as those present in reactor systems, to be modeled without impractical computational resources.

System Scope

The MOOSE Thermal Hydraulics module provides several additional systems, including a component system, a closures system, and a control logic system. The module includes basic components such as two-dimensional and three-dimensional heat structures, which solve the transient heat conduction equation, along with components that provide heat sources, boundary conditions, and interface conditions to these components. The module also includes a suite of components for solving single-phase flow, using numerical methods most suitable for compressible gas flows. These single-phase flow components include flow channels, junctions, valves, walls, and inlets/outlets. Additionally, the module provides turbomachinery components such as a shaft, motor, compressor, and turbine. In addition to components, the module provides basic closures for the single-phase flow model, as well as control logic objects such as delays, trips, and PID controllers.

System Overview

System Context

The Thermal Hydraulics module is command-line driven. Like MOOSE, this is typical for a high-performance software that is designed to run across several nodes of a cluster system. As such, all usage of the software is through any standard terminal program generally available on all supported operating systems. Similarly, for the purpose of interacting through the software, there is only a single user, "the user", which interacts with the software through the command-line. The Thermal Hydraulics module does not maintain any back-end database or interact with any system daemons. It is an executable, which may be launched from the command line and writes out various result files as it runs.

Figure 1: Usage of the Thermal Hydraulics module and other MOOSE-based applications.

System Functions

Since the Thermal Hydraulics module is a command-line driven application, all functionality provided in the software is operated through the use of standard UNIX command line flags and the extendable MOOSE input file. The Thermal Hydraulics module is completely extendable so individual design pages should be consulted for specific behaviors of each user-defined object.

User Characteristics

Like MOOSE, there are three kinds of users working on the Thermal Hydraulics module:

Thermal Hydraulics module Developers: These are the core developers of the Thermal Hydraulics module. They are responsible for following and enforcing the software development standards of the module, as well as designing, implementing, and maintaining the software.
Developers: A scientist or engineer that uses the Thermal Hydraulics module alongside MOOSE to build their own application. This user will typically have a background in modeling or simulation techniques (and perhaps numerical analysis) but may only have a limited skillset when it comes to code development using the C++ language. This is the primary focus group of the module. In many cases, these developers will be encouraged to contribute module-appropriate code back to the Thermal Hydraulics module, or to MOOSE itself.
Analysts: These are users that will run the code and perform analysis on the simulations they perform. These users may interact with developers of the system requesting new features and reporting bugs found and will typically make heavy use of the input file format.

Assumptions and Dependencies

The Thermal Hydraulics module is developed using MOOSE and can itself be based on various MOOSE modules, as such the SRS for the Thermal Hydraulics module is dependent upon the files listed at the beginning of this document. Any further assumptions or dependencies are outlined in the remainder of this section.

The Thermal Hydraulics module is designed with the fewest possible constraints on hardware and software. For more context on this point, the Thermal Hydraulics module SRS defers to the framework Assumptions and Dependencies. Any physics-based or mathematics-based assumptions in code simulations and code objects are highlighted in their respective documentation pages.

References

ISO/IEC/IEEE 24765:2010(E). Systems and software engineering—Vocabulary. first edition, December 15 2010.

@manual{ISO-systems-software,
    author = "24765:2010(E), ISO/IEC/IEEE",
    title = "Systems and software engineering---Vocabulary",
    edition = "First",
    year = "2010",
    month = "December 15"
}

ASME NQA-1. ASME NQA-1-2008 with the NQA-1a-2009 addenda: Quality Assurance Requirements for Nuclear Facility Applications. first edition, August 31 2009.

@manual{ASME-NQA-1-2008,
    author = "NQA-1, ASME",
    title = "ASME NQA-1-2008 with the NQA-1a-2009 addenda: Quality Assurance Requirements for Nuclear Facility Applications",
    orginization = "American Socieity of Mechanical Engineers",
    year = "2009",
    month = "August 31",
    edition = "First"
}

Definitions and Acronyms

This section defines, or provides the definition of, all terms and acronyms required to properly understand this specification.

Definitions

Verification: (1) The process of: evaluating a system or component to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase. (2) Formal proof of program correctness (e.g., requirements, design, implementation reviews, system tests) (24765:2010(E), 2010).

Acronyms

Acronym	Description
INL	Idaho National Laboratory
LGPL	GNU Lesser General Public License
MOOSE	Multiphysics Object Oriented Simulation Environment
NQA-1	Nuclear Quality Assurance Level 1
POSIX	Portable Operating System Interface
SRS	Software Requirement Specification

System Requirements

In general, the following is required for MOOSE-based development:

A POSIX compliant Unix-like operating system. This includes any modern Linux-based operating system (e.g., Ubuntu, Fedora, Rocky, etc.), or a Macintosh machine running either of the last two MacOS releases.

Hardware	Information
CPU Architecture	x86_64, ARM (Apple Silicon)
Memory	8 GB (16 GBs for debug compilation)
Disk Space	30GB

Libraries	Version / Information
GCC	8.5.0 - 12.2.1
LLVM/Clang	10.0.1 - 16.0.6
Intel (ICC/ICX)	Not supported at this time
Python	3.7 - 3.11
Python Packages	packaging pyaml jinja2

Functional Requirements

thermal_hydraulics: Actions
11.1.1
The system shall be able to couple solid heat conduction region to a 1-D flow channel via convective heat transfer
1. Without sub-app positions provided.
2. With sub-app positions provided.
3. With multiple phases.
11.1.2The system shall report an error for the coupled heat transfer action if the mesh is not aligned with the x, y, or z axis.

thermal_hydraulics: Auxkernels
11.2.1The system shall compute convective heat flux between fluid and wall temperature for 1-phase flow
11.2.2The system shall be able to compute the Mach number for 1D single phase flow.
11.2.3The system shall be able to compute the local Prandtl number in a 1D single phase channel.
11.2.4The system shall be able to compute the local Reynolds number in a 1D single phase channel.
11.2.5The system shall be able to compute the local sound of speed in the fluid in a 1D single phase channel.
11.2.6The system shall be able to compute the sum of two fields.
11.2.7The system shall be able to compute the weighted average of several fields.

thermal_hydraulics: Base
11.3.1The system shall allow nesting components into groups in input files
11.3.2The system shall be able to output the component loops to console.

thermal_hydraulics: Closures
11.4.1
The system shall compute the heat transfer coefficient and the friction factor when used with:
1. the Dittus-Boelter correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
2. the Kazimi-Carelli correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
3. the Lyon correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
4. the Mikityuk correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
5. the Schad correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
6. the Weisman correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
7. the Wolf-McCarthy correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
8. the Gnielinski correlation for the Heat Transfer Coefficient and the Churchill or Cheng-Todreas correlation for the friction factor
9. the friction factor is prescribed by the user
11.4.2The system shall be able to define a closure object that does not define closures, so they can be defined directly in the input file.
11.4.3The system shall report an error with a useful message if the user attempts the former way of not specifying closures.
11.4.4The system shall report an error if the friction parameter is missing in the simple closures object.
11.4.5The system shall report an error if the user attempts passing closure parameters directly to components.

thermal_hydraulics: Components
11.5.1The system shall report an error if a component specified in a parameter does not exist.
11.5.2The system shall report an error if the components are not setup in the expected order and are not in the correct setup status for an operation.
11.5.3The system shall report an error if the FreeBoundary component is used.
11.5.4The system shall report an error if the GateValve component is used.
11.5.5The system shall report an error if the SolidWall component is used.
11.5.6The system shall report an error if the JunctionOneToOne component is used.
11.5.7The system shall report an error if the HeatGeneration component is used.
11.5.8The system shall report an error if the HeatSourceVolumetric component is used.
11.5.9The system shall report an error if the PrescribedReactorPower component is used.
11.5.10The system shall be able to model flow through a 1D elbow pipe.
11.5.11The system shall generate a mesh for the FileMeshComponent test.
11.5.12The system shall provide a component that loads a mesh from an ExodusII file.
11.5.13The system shall report an error for FileMeshComponent when the file is not readable.
11.5.14
The system shall simulate a single-phase flow channel
1. with a friction factor provided by a function.
2. with a hydraulic diameter provided by a function.
3. with multiple length subsections.
4. in a steady problem.
11.5.15The system shall report an error if fluid properties are not single-phase.
11.5.16The system shall have correct Jacobians for the single-phase flow channel.
11.5.17The system shall generate a mesh for a test creating a Navier Stokes flow simulation with components.
11.5.18The system shall model the porous, incompressible Navier-Stokes equations with a finite volume discretization, using a component.
11.5.19The system shall report an error if a non-existent component is specified in a flow connection component.
11.5.20The system shall report an error if the old syntax for component connections is being used in an input file.
11.5.21The system shall report an error if an incorrect syntax is used for an inlet or outlet of a component to be connected.
11.5.22The system shall be able to compute a form loss using data transfered from a multiapp.
11.5.23The system shall be able to compute a form loss using coefficients computed from a function, including constants defined in the input file.
11.5.24The system shall be able to specify a free surface boundary at the inlet and outlet and show conservation of mass.
11.5.25The system shall be able to specify a free surface boundary at the inlet and outlet and show conservation of momentum.
11.5.26The system shall be able to specify a free surface boundary at the inlet and outlet and show conservation of energy.
11.5.27The system shall be able to simulate a gate valve in between two components for a full transient.
11.5.28The system shall be able to simulate a gate valve in between two components for a few time steps.
11.5.29The system shall be able to simulate a gate valve in between two components with the component oriented in either direction.
11.5.30The system shall report an error if a gate valve is connected to more than two components.
11.5.31The system shall report an error if the two components connected to a gate valve are not parallel.
11.5.32The system shall report an error if a gate valve is requested to perform slope reconstruction.
11.5.33The system shall report an error if a TRAP quadrature is used with second order components.
11.5.34The system shall provide the heat source shape when power density is supplied
11.5.35The system shall be able to apply a heat source, computed from a power density, onto a component whose mesh is loaded from a mesh file.
11.5.36The system shall report an error if the heat structure specified to apply a heat source on is not of the adequate type.
11.5.37The system shall report an error if the specified subdomain to apply a heat source on does not exist.
11.5.38The system shall provide the heat source shape for a cylindrical heat structure when power component and power shape function are supplied
11.5.39The system shall provide the heat source shape for a plate heat structure when power component and power shape function are supplied
11.5.40The system shall be able to impose a heat source from the component, computed from the component power and shape shape, onto a plate heat structure component and prove conservation of energy.
11.5.41The system shall be able to impose a heat source from the component, computed from the component power and shape shape, onto a cylindrical heat structure component and prove conservation of energy.
11.5.42The system shall be able to apply a heat source, computed from the component power norm and shape, onto a component whose mesh is loaded from a mesh file.
11.5.43The system shall report an error if the heat structure to apply a heat source on, computed from the component power norm and shape, is not of the expected heat structure interface type.
11.5.44The system shall report an error if the specified subdomain to apply a heat source on, computed from the component power norm and shape, does not exist.
11.5.45The system shall report an error if the heat structure to apply a heat source on, computed from the component power norm and shape, is not of the expected type.
11.5.46The system shall be able to specify a volumetric heat source in a component and still prove conservation of energy.
11.5.47The system shall report an error if the component specified to a volumetric heat source does not exist.
11.5.48The system shall report an error if the component specified to a volumetric heat is not of the supported flow channel type.
11.5.49The system shall be able to couple two 2D cylindrical heat structures.
11.5.50The system shall be able to couple two 2D plate heat structures.
11.5.51The system shall be able to couple two 2D cylindrical heat structures on separated surfaces.
11.5.52
The system shall report an error for HeatStructure2DCoupler when
1. the provided heat structure boundary does not exist.
2. the types of the coupled heat structures do not match.
3. the types of either coupled heat structure is invalid.
4. the boundary meshes are not aligned.
11.5.53The system shall be able to couple two 2D cylindrical heat structures via radiation and conserve energy.
11.5.54
The system shall report an error for HeatStructure2DRadiationCouplerRZ when
1. the provided heat structure boundary does not exist.
2. the type of either coupled heat structure is invalid.
3. the boundary meshes are not aligned.
11.5.55The system shall be able to solve for the thermal behavior of a heat structure with several axial regions.
11.5.56The system shall be able to initialize the temperature in a heat structure using a function.
11.5.57The system shall be able to solve for the thermal behavior of a heat structure with several axial regions with different axial discretizations.
11.5.58The system shall be able to discretize the inner boundary of a heat structure.
11.5.59The system shall be able to create interior axial boundaries in a heat structure.
11.5.60The system shall be able to use a second order mesh in a heat structure.
11.5.61
The system shall report an error if
1. several axial regions are specified but only one name for the axial regions is passed,
2. the user specified non-matching numbers of axial regions and axial lengths,
3. the user attempts to use a TRAP quadrature with second order elements,
4. the user does not specify the initial temperature to a heat structure component,
5. the user does not specify a matching number of names and discretizations for every part in a cylindrical heat structure,
6. the user does not specify a matching number of names and widths for every part in a cylindrical heat structure,
7. the user does not specify a matching number of names and solid properties for every part in a cylindrical heat structure.
11.5.62
The system shall simulate a 2D cylindrical heat structure
1. in a transient problem, with properties defined by HeatStructureMaterials.
2. in a transient problem, with properties defined by Materials.
3. in a transient problem, with properties defined by SolidProperties.
4. in a steady problem.
11.5.63The system shall be able to use an external mesh file to create a 3D heat structure.
11.5.64The system shall report an error if the mesh from an external mesh file for a 3D heat structure is not 3D.
11.5.65
The system shall be able to model heat conduction in a 2-D plate
1. with properties defined by HeatStructureMaterials.
2. with properties defined by Materials.
3. with properties defined by SolidProperties.
11.5.66The system shall report an error if heat sources in a flow channel are a mix of specified temperatures and specified heat fluxes.
11.5.67The system shall be able to solve for single phase heat transfer in a component with the wall heat flux provided by an external application.
11.5.68The system shall be able to solve for single phase heat transfer in a component with the wall temperature provided by an external application.
11.5.69The system shall be able to solve for single phase heat transfer in a component with the exterior temperature provided by an external application.
11.5.70The system shall be able to solve for single phase heat transfer in a component with the wall temperature provided by an external application and represented as an elemental field.
11.5.71The system shall allow application of multiple heat fluxes to a single-phase flow channel.
11.5.72The system shall conserve energy when applying a heat flux function to a single-phase flow channel.
11.5.73The system shall allow heat transfer names to be named with the heat transfer object as a suffix when there are multiple heat fluxes applied to a single-phase flow channel.
11.5.74The system shall be able to couple a flow channel and heat structure aligned with the x-axis.
11.5.75The system shall be able to couple a flow channel and heat structure with non-uniform meshes and opposite directions.
11.5.76The system shall be able to couple a flow channel and heat structure aligned with the y-axis.
11.5.77The system shall be able to couple a flow channel and heat structure aligned with the z-axis.
11.5.78The system shall conserve energy when a flow channel is coupled to a plate heat structure.
11.5.79The system shall conserve energy when a flow channel is coupled to a cylindrical heat structure.
11.5.80The system shall conserve energy when a flow channel is coupled to several heat structures.
11.5.81The system shall conserve energy after reaching steady-state when a flow channel is coupled to a heat structure.
11.5.82The system shall be able to enhance heat transfer between a flow channel and heat structure using fins.
11.5.83The system shall throw an error if the flow channel component is not of type 'FlowChannelBase'.
11.5.84The system shall throw an error if the heat structure component is not of type 'HeatStructureBase'.
11.5.85The system shall throw an error if the provided heat structure side is invalid.
11.5.86The system shall throw an error if the heat structure and flow channel components don't have the same number of axial elements.
11.5.87The system shall throw an error if the heat structure and flow channel components don't have the same length.
11.5.88The system shall throw an error if the center of the elements of the flow channel component don't align with the centers of the specified heat structure side.
11.5.89The system shall throw an error if the coupled flow channel and heat structure components don't have the same orientation.
11.5.90The system shall throw an error if the flow channel is coupled to the inner side of a heat structure that has a zero inner radius.
11.5.91The system shall throw an error if the heat transfer coefficient is not specified with simple closures.
11.5.92The system shall compute jacobians when a flow channel is coupled to the outer side of a cylindrical heat structure.
11.5.93The system shall compute jacobians when a flow channel is coupled to the inner side of a cylindrical heat structure.
11.5.94The system shall compute jacobians when a flow channel is coupled to the outer side of a plate heat structure.
11.5.95The system shall compute jacobians when a flow channel is coupled to the inner side of a plate heat structure.
11.5.96The system shall conserve energy when using HeatTransferFromHeatStructure3D1Phase.
11.5.97The system shall allow to connect multiple flow channels to a single boundary in HeatTransferFromHeatStructure3D1Phase.
11.5.98The system shall allow to connect flow channels that have negative orientation to a HeatTransferFromHeatStructure3D1Phase component.
11.5.99The system shall throw an error if a flow channel connected to a HeatTransferFromHeatStructure3D1Phase component is not a FlowChannel1Phase.
11.5.100The system shall throw an error if a flow channel connected to a HeatTransferFromHeatStructure3D1Phase component is not aligned with the x-, y-, or z- axis.
11.5.101The system shall throw an error if the heat structure connected to a HeatTransferFromHeatStructure3D1Phase component is not a HeatStructureFromFile3D component.
11.5.102The system shall throw an error if the heat structure boundary connected to a HeatTransferFromHeatStructure3D1Phase component doesn't exist.
11.5.103The system shall throw an error if the flow channels connected to a HeatTransferFromHeatStructure3D1Phase component are not aligned with the same axis.
11.5.104The system shall throw an error if the flow channels connected to a HeatTransferFromHeatStructure3D1Phase component don't have the same lnumber of elements.
11.5.105The system shall throw an error if the flow channels connected to a HeatTransferFromHeatStructure3D1Phase component don't have the same length.
11.5.106The system shall correctly compute Jacobians for HeatTransferFromHeatStructure3D1Phase.
11.5.107The system shall be able to solve for heat transfer with a specified wall temperature.
11.5.108The system shall be able to solve for heat transfer with a specified wall temperature, and dynamically controlling the wall heat transfer coefficient.
11.5.109The system shall be able to solve for heat transfer with a specified wall temperature, and dynamically controlling the wall temperature.
11.5.110The system shall report an error if an invalid side is specified for setting a heat structure on a flow channel component.
11.5.111The system shall be able to simulate ambient convection on the boundary of a cylindrical heat structure and show conservation of energy.
11.5.112The system shall be able to simulate ambient convection on the boundary of a plate heat structure and show conservation of energy.
11.5.113The system shall be able to simulate ambient convection on the boundary of a heat structure created from a 3D mesh in a file and show conservation of energy.
11.5.114The system shall be able to enhance convective heat transfer on the boundary of a cylindrical heat structure using fins.
11.5.115The system shall be able to simulate convection on the boundary of a heat structure with an external temperature and the wall heat transfer coefficient transferred from an external application.
11.5.116The system shall be able to generate a mesh for testing a heat structure imposing a heat flux from an external application.
11.5.117The system shall be able to apply a heat flux from an external application to a heat structure.
11.5.118
The system shall report an error for a heat structure boundary object imposing a heat flux from an external application if
1. the heat structure is not cylindrical, or
2. the heat structure boundary specified for the heat flux is not the inner or outer boundary.
11.5.119The system shall be able to simulate convection on the boundary of a heat structure with an external temperature transferred from an external application.
11.5.120The system shall be able to apply a heat flux boundary condition on the boundary of a cylindrical heat structure and show conservation of energy.
11.5.121The system shall be able to apply a heat flux boundary condition on the boundary of a plate heat structure and show conservation of energy.
11.5.122The system shall be able to apply a heat flux boundary condition on the boundary of a heat structure created from a 3D mesh file and show conservation of energy.
11.5.123The system shall be able to apply a radiative heat flux boundary condition on the boundary of a cylindrical heat structure and show conservation of energy.
11.5.124The system shall be able to apply a radiative heat flux boundary condition on the boundary of a plate heat structure and show conservation of energy.
11.5.125The system shall be able to apply a radiative heat flux boundary condition on the boundary of a heat structure created from a 3D mesh file and show conservation of energy.
11.5.126The system shall report an error if a user requests a heat structure boundary condition be created on a side with zero perimeter of the heat structure.
11.5.127
The system shall be able to couple an arbitrary number cylindrical heat structures via radiation using a general formulation
1. and for a concentric cylinder problem produce an identical solution to the solution obtained using concentric cylinder assumptions.
2. and be able to include the environment.
3. and conserve energy.
4. and shall report an error when the view factors are provided incorrectly.
5. and shall report an error when the view factor matrix rows do not sum to one.
11.5.128The system shall have correct input for the HSCoupler2D3D test mesh.
11.5.129
The system shall couple a 2D heat structure with a 3D heat structure
1. using conduction and radiation.
2. using conduction only.
3. using convection only.
11.5.130
The system shall report an error for HSCoupler2D3D
1. If the 2D heat structure does not exist.
2. If the 3D heat structure does not exist.
3. If the 2D heat structure boundary does not exist.
4. If the 3D heat structure boundary does not exist.
5. If the meshes of the heat structures are not aligned.
6. If the max AD container size is predicted to be exceeded.
7. If the gap thickness is less than or equal to zero.
8. If radiation is specified to be included but the emissivities are not provided.
9. If radiation is specified to not be included but an emissivity is provided.
11.5.131The system shall be able to set an inlet boundary condition for 1D single phase flow by setting the fluid density and its velocity at the boundary.
11.5.132The system shall be able to control both the density and the velocity at an inlet with single phase flow.
11.5.133The system shall be able to set an inlet boundary condition for 1D single phase flow by setting the fluid density and its velocity at the boundary, and show numerically accurate Jacobians.
11.5.134The system shall be able to model an inlet boundary condition for 1D single phase flow with a specified mass flow rate and temperature at the inlet.
11.5.135The system shall be able to model an inlet boundary condition for 1D single phase flow with a specified mass flow rate and temperature at the inlet, and handle flow reversal.
11.5.136The system shall be able to control the mass flow rate at a 1D single phase flow inlet defined by a temperature and a mass flow rate.
11.5.137The system shall be able to control the fluid temperature at a 1D single phase flow inlet defined by a temperature and a mass flow rate.
11.5.138The system shall compute numerically accurate Jacobians when using an inlet with specified mass flow rate and temperature.
11.5.139The system shall compute numerically accurate Jacobians when using an inlet with specified mass flow rate and temperature, when using IAPWS-97 water fluid properties.
11.5.140The system shall report an error if a user attempts to use rDG with an inlet boundary condition specified from the stagnation enthalpy and momentum.
11.5.141The system shall be able to specify an inlet boundary condition for 1D single phase flow in steady state from the stagnation pressure and temperature.
11.5.142The system shall be able to specify an inlet boundary condition for 1D single phase flow in a transient from the stagnation pressure and temperature.
11.5.143The system shall be able to specify an inlet boundary condition for 1D single phase flow in a longer transient from the stagnation pressure and temperature.
11.5.144The system shall be able to control the stagnation pressure in a 1D single phase flow inlet specified using the stagnation pressure and temperature.
11.5.145The system shall be able to control the stagnation temperature in a 1D single phase flow inlet specified using the stagnation pressure and temperature.
11.5.146The system shall be able to specify an inlet boundary condition for 1D single phase flow in steady state from the inlet flow velocity and temperature.
11.5.147The system shall be able to specify an inlet boundary condition for 1D single phase flow in steady state from the inlet flow velocity and temperature, and handle flow reversal.
11.5.148The system shall be able to control the inlet flow velocity and temperature in a 1D single phase flow inlet specified using the flow velocity and temperature.
11.5.149The system shall be able to connect flow in two flow channel components using a junction.
11.5.150The system shall be able to connect flow in two flow channel components using a junction, even if one is flipped in the opposite direction of the other.
11.5.151The system shall be able to connect flow in two flow channel components of different flow areas using a junction.
11.5.152The system shall be able to solve for flow in two connected pipes and in a single pipe of equivalent length and produce the same results.
11.5.153The system shall be able to connect an arbitrary number of parallel channels to another flow component.
11.5.154The system shall be able to connect an arbitrary number of single phase parallel channels with different flow areas to another flow component.
11.5.155The system shall be able to check the syntax for connecting two parallel channels with different single phase fluid temperatures and mix the flows.
11.5.156The system shall be able to connect two parallel channels with different single phase fluid temperatures and mix the flows.
11.5.157The system shall be able to connect an arbitrary number of parallel channels to another flow component, with a calorifically imperfect gas fluid.
11.5.158The system shall be able to show conservation of mass and energy when connecting parallel channels.
11.5.159The system shall be able to show conservation of mass and energy when connecting parallel channels and leveraging the control system to dynamically control the simulation.
11.5.160The system shall report an error if no initial conditions were set in a parallel junction.
11.5.161The system shall report an error if a parallel junction is set to connect non-parallel flow channels.
11.5.162The system shall be able to compute a numerically accurate Jacobian when connecting parallel single phase channels.
11.5.163The system shall be able to model an outlet connected to a sealed pipe with 1D single phase compressible flow.
11.5.164The system shall be able to control the pressure at a pressure outlet dynamically during a 1D single phase flow simulation.
11.5.165The system shall be able to compute numerically accurate Jacobians for 1D single phase flow with a pressure outlet.
11.5.166The system shall be able to generate a simple rectangular mesh for the physics component tests.
11.5.167The system shall be able to create a component leveraging the Physics syntax to define equations.
11.5.168The system shall be able to model a pump in 1D single phase flow and show conservation of mass and energy.
11.5.169The system shall be able to model a pump in 1D single phase flow within a slanted pipe and show conservation of mass and energy.
11.5.170The system shall be able to compute the expected pressure rise when modeling a pump in 1D single phase flow.
11.5.171The system shall be able to compute the expected pressure rise when modeling a pump in 1D single phase flow with an orientation not aligned with one of the frame axis.
11.5.172The system shall be able to compute the expected pressure rise when modeling a pump in 1D single phase flow with the flow aligned with the X axis.
11.5.173The system shall be able to compute the expected pressure rise when modeling a pump in 1D single phase flow with the flow aligned with the Y axis.
11.5.174The system shall be able to model a pump in a 1D single phase flow loop.
11.5.175The system shall allow for controlling the pump head
11.5.176The system shall allow for controlling the pump head and maintain a numerically correct Jacobian.
11.5.177The system shall report an error if a shaft is created with no connected components.
11.5.178The system shall conserve mass and energy when using ShaftConnectedCompressor1Phase.
11.5.179The system shall be able to model a compressor with ShaftConnectedCompressor1Phase.
11.5.180The system shall allow ShaftConnectedCompressor1Phase to run with a zero shaft speed.
11.5.181The system shall correctly compute Jacobians for ShaftConnectedCompressor1Phase.
11.5.182The system shall throw an error if ShaftConnectedCompressor1Phase is not connected to a shaft component.
11.5.183The system shall throw an error if the initial shaft speed is not provided and the application is not restarting.
11.5.184The system shall throw an error if ShaftConnectedMotor is not connected to a shaft component.
11.5.185The system shall be able to model a motor connected to a shaft.
11.5.186The system shall be able to execute a restart a simulation involving a shaft-connected motor.
11.5.187The system shall allow the torque of a shaft-connected motor to be controlled.
11.5.188The system shall allow the inertia of a shaft-connected motor to be controlled.
11.5.189The system shall conserve mass and energy when using ShaftConnectedPump1Phase.
11.5.190The system shall be able to model a pump with ShaftConnectedPump1Phase.
11.5.191The system shall be able to model a pump coastdown with ShaftConnectedPump1Phase.
11.5.192The system shall correctly compute Jacobians for ShaftConnectedPump1Phase.
11.5.193The system shall throw an error if ShaftConnectedPump1Phase is not connected to a shaft component.
11.5.194The system shall conserve mass and energy when using ShaftConnectedTurbine1Phase.
11.5.195The system shall be able to model a turbine with ShaftConnectedTurbine1Phase.
11.5.196The system shall be able to model a turbine startup with ShaftConnectedTurbine1Phase.
11.5.197The system shall correctly compute Jacobians for ShaftConnectedTurbine1Phase.
11.5.198The system shall throw an error if ShaftConnectedTurbine1Phase is not connected to a shaft component.
11.5.199The system shall be able to model a simple turbine in 1D single phase compressible flow and show mass and energy conservation.
11.5.200The system shall be able to model a simple turbine in 1D single phase compressible flow.
11.5.201The system shall be able to control the turbine power in a 1D single phase compressible flow simulation with a simple turbine.
11.5.202The system shall be able to compute a numerically accurate Jacobian when using a simple turbine model in a 1D single phase compressible flow simulation.
11.5.203The system shall be able to model a wall in a 1D single phase compressible flow simulation.
11.5.204The system shall be able to compute a numerically accurate Jacobian when using a wall inlet (with no flow) in a 1D single phase compressible flow simulation.
11.5.205The system shall report an error if the SupersonicInlet component is used.
11.5.206The system shall be able to apply a heat source in a heat structure component.
11.5.207The system shall be able to dynamically control the heat source in a heat structure component.
11.5.208
The system shall be able model a flow junction to connect:
1. 2 pipes of equal area in the x direction,
2. 2 pipes of equal area not in the x direction,
3. 2 pipes of unequal area,
4. 3 pipes, 1 of which going to a dead-end,
5. 2 pipes with different temperatures mixing together into a third pipe with correct syntax,
6. 2 pipes with different temperatures mixing together into a third pipe with correct results,
7. pipes with the calorically imperfect gas fluid properties,
11.5.209
The system shall allow the user to prescribe form losses in the volume jucntion component:
1. by specifying a constant loss coefficient and using the area of the first connected pipe,
2. by specifying a constant loss coefficient and a reference flow area, and
3. by specifying the loss coefficient through the control system.
11.5.210The system shall conserve mass and energy when a VolumJunction1Phase component is used
11.5.211The system shall throw an error if initial conditions for the VolumeJunction1Phase component are missing.
11.5.212The system shall throw an error if the parameter "A_ref" is specifed and the paramter "K" is not specified.

thermal_hydraulics: Controls
11.6.1The system shall be able to use postprocessor values to dynamically control input parameters in a simulation.
11.6.2The system shall be able to delay a control signal in time.
11.6.3The system shall report an error if the delay for the action of a control is set by the user to be negative.
11.6.4The system shall use dependency resolution to execute Control objects in the correct order.
11.6.5The system shall report an error if non-existent control data is requested in a control logic object.
11.6.6The system shall be able to use the value of a function to define a control data, to be used in control logic.
11.6.7The system shall provide a control that evaluates a parsed function
11.6.8The system shall be able to use a proportional-integral-derivative law to adjust controllable flow parameters to be able to match a desired target quantity.
11.6.9The system shall be able to set a boolean parameter to the value of a boolean control data.
11.6.10The system shall be able to set a component boolean parameter to the value of a boolean control data.
11.6.11The system shall be able to set a component floating point parameter to the value of a floating point control data.
11.6.12The system shall be able to set a floating point parameter to the value of a floating point control data.
11.6.13The system shall be able to smooth an input signal using a moving average.
11.6.14The system shall be able to use control logic to terminate a simulation gracefully.
11.6.15The system shall be able to use control logic to terminate a simulation with an error.
11.6.16The system shall be able to decide whether to solve a flow simulation problem depending on the value of a postprocessor.
11.6.17The system shall be able to execute controls at the beginning of simulation time steps.
11.6.18The system shall provide a unit trip component that report true if the trip condition was met and false otherwise.
11.6.19The system shall provide a unit trip component that stays in tripped state after the trip happened.
11.6.20The system shall report an error when an unit trip condition does not evaluate as boolean value.

thermal_hydraulics: Functions
11.7.1The system shall be able to piece together several functions in a given axis, directly from the input file.
11.7.2The system shall report an error if the the user passes an inconsistent number of functions to piece together and number of points of connections between the functions.
11.7.3The system shall report an error if the the user passes points of connections between functions to piece together that are not in increasing order.
11.7.4The system shall report an error if the user references a function to piece functions together in the list of function pieced together, hence creating an infinite recursion.
11.7.5The system shall be able to use a cosine shape to smoothly transition between two functions of space.
11.7.6The system shall be able to use a cosine shape to smoothly transition between two functions of time.
11.7.7The system shall be able to use a cubic polynomial shape to smoothly transition between two functions of space.
11.7.8The system shall be able to use a cubic polynomial shape to smoothly transition between two functions of time.

thermal_hydraulics: Interfaces
11.8.1The system shall provide an interface to compute an axial coordinate from an arbitrary spatial point.
11.8.2The system shall provide an interface to compute a radial coordinate from an arbitrary spatial point.
11.8.3The system shall provide an interface to get the axial section index for an arbitrary spatial point.
11.8.4The system shall provide an interface to get the axial element index for an arbitrary spatial point.
11.8.5
The system shall report an error for the discrete line segment interface
1. if an invalid axial coordinate is provided.

thermal_hydraulics: Jacobians
11.9.1The system shall be able to compute numerically accurate Jacobians when specifying a convective heat transfer boundary condition.
11.9.2The system shall be able to compute numerically accurate Jacobians when specifying a cylindrical convective heat transfer boundary condition in a cartesian frame of reference.
11.9.3The system shall be able to compute numerically accurate Jacobians when specifying an external convection boundary condition using data from an external application.
11.9.4The system shall be able to compute numerically accurate Jacobians when specifying a cylindrical external convection boundary condition using data from an external application, within a cartesian frame of reference.
11.9.5The system shall be able to compute numerically accurate Jacobians when specifying a radiative boundary condition.
11.9.6The system shall be able to compute numerically accurate Jacobians when specifying a radiative boundary condition using cylindrical coordinates in a cartesian frame of reference.
11.9.7The system shall be able to compute numerically accurate Jacobians when constraining the momentum equation on selected nodes.
11.9.8The system shall be able to compute numerically accurate Jacobians when computing the advection momentum flux.
11.9.9The system shall be able to compute numerically accurate Jacobians when computing the contribution from the flow area variation to the momentum equation.
11.9.10The system shall be able to compute numerically accurate Jacobians when computing the contribution from the flow friction loss to the momentum equation.
11.9.11The system shall be able to compute numerically accurate Jacobians when computing the contribution from the energy advection term to the fluid energy equation.
11.9.12The system shall be able to compute numerically accurate Jacobians when computing the contribution from the wall convection term to the fluid energy equation.
11.9.13The system shall be able to compute numerically accurate Jacobians when computing the contribution from gravity to the momentum equation.
11.9.14The system shall be able to compute numerically accurate Jacobians when computing the contribution from gravity to the fluid energy equation.
11.9.15The system shall be able to compute numerically accurate Jacobians when computing the contribution from a heat source to the fluid energy equation.
11.9.16The system shall be able to use the material property system to define solid properties for a solid energy equation.
11.9.17The system shall be able to compute a numerically accurate Jacobian when using a constant material to define a property and its (null) derivatives with regards to the nonlinear conserved variables.
11.9.18The system shall be able to compute a numerically accurate Jacobian when computing density as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.19The system shall be able to compute a numerically accurate Jacobiain when computing the dynamic viscosity and its derivatives with regards to the nonlinear conserved variables.
11.9.20The system shall be able to compute a numerically accurate Jacobian when computing the constant derivatives of material properties linearly dependent on the nonlinear conserved variables.
11.9.21The system shall be able to compute a numerically accurate Jacobian when computing pressure as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.22The system shall be able to compute a numerically accurate Jacobian when computing specific internal energy as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.23The system shall be able to compute a numerically accurate Jacobian when computing specific volume as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.24The system shall be able to compute a numerically accurate Jacobian when computing velocity as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.25The system shall be able to compute a numerically accurate Jacobian when computing specific enthalpy as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.26The system shall be able to compute a numerically accurate Jacobian when computing the Reynolds number and its derivatives with regards to the nonlinear conserved variables.
11.9.27The system shall be able to compute a numerically accurate Jacobian when computing temperature as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.28The system shall be able to compute a numerically accurate Jacobian when computing total enthalpy as a fluid property and its derivatives with regards to the nonlinear conserved variables.
11.9.29The system shall be able to compute a numerically accurate Jacobian when computing a wall friction coefficient from functions and its derivatives with regards to the nonlinear conserved variables.
11.9.30The system shall be able to compute a numerically accurate Jacobian when computing a Churchill correlation wall friction coefficient and its derivatives with regards to the nonlinear conserved variables.
11.9.31The system shall be able to compute a numerically accurate Jacobian when using a shaft-connected motor in a flow loop.

thermal_hydraulics: Materials
11.10.1The system shall be able to compute the average wall temperature and store it as a material property to be able to propagate derivatives through automatic differentiation.
11.10.2The system shall be able to compute the average wall temperature and store it as a material property to be able to propagate derivatives through automatic differentiation, even with null wall heat transfer coefficients,
11.10.3The system shall report an error if the number of wall heat transfer coefficients does not match the number of wall temperatures when computing average wall temperatures.
11.10.4The system shall report an error if the number of wall heated perimeters does not match the number of wall temperatures when computing average wall temperatures.
11.10.5The system shall be able to compute the convective heat flux and store it as a material property to be able to propagate derivatives through automatic differentiation.
11.10.6The system shall be able to compute the convective heat flux in a heat structure and store it as a material property to be able to propagate derivatives through automatic differentiation.
11.10.7
The system shall compute the heat transfer coefficient as a function of the Nusselt number:
1. using the default name
2. using a name provided in the input file.
11.10.8The system shall be able to multiply a function by a material property and define the product as a material property.
11.10.9The system shall compute the Prandlt number as a material property.
11.10.10The system shall compute the Reynolds number as a material property.
11.10.11The system shall be able to compute the wall heat transfer coefficient using the Dittus Boelter correlation and automatic differentation.
11.10.12The system shall be able to rename the wall heat transfer coefficient computed with the Dittus Boelter correlation and automatic differentiation.
11.10.13The system shall compute the heat transfer coefficient using the Gnielinski correlation for the Nusselt number
11.10.14
The system shall return a warning message when the Gnielinski correlation is used with:
1. Reynolds number out of bonds, or
2. Prandtl out of bonds.
11.10.15The system shall compute the heat transfer coefficient using the Kazime-Carelli correlation for the Nusselt number
11.10.16
The system shall return a warning message when the Kazimi-Carelli correlation is used with:
1. pitch-to-diameter out of bonds, or
2. Peclet out of bonds.
11.10.17The system shall compute the heat transfer coefficient using the Lyon correlation for the Nusselt number
11.10.18The system shall compute the the heat transfer coefficient using the Mikityuk correlation for the Nusselt number.
11.10.19
The system shall return a warning message when the Mikityuk correlation is used with:
1. pitch-to-diameter ratioout of bonds, or
2. Peclet number out of bonds.
11.10.20
The system shall compute the the heat transfer coefficient using the Schad correlation for the Nusselt number for
1. Peclet numbers above or equal to 150, or
2. Peclet numbers below 150.
11.10.21
The system shall return a warning message when the Schad correlation is used with:
1. Pitch-to-diameter out of bonds, or
2. Peclet out of bonds.
11.10.22
The system shall compute the the heat transfer coefficient using the Weisman correlation for:
1. square array rod bundle or,
2. triangular array rod bundle.
11.10.23
The system shall return a warning message when the Weisman correlation is used with:
1. pitch-to-diameter out of bonds for a square array rod bundle,
2. pitch-to-diameter ratio out of bonds for a triangular array rod bundle,
11.10.24The system shall be able to compute the convective heat transfer coefficient using the Wolf-McCarthy correlation.
11.10.25
The system shall compute the heat transfer coefficient using the Gnielinski correlation for annular turbulent flows:
1. when the fluid is a gas and heat transfer is at the inner side of the annulus
2. when the fluid is a gas and heat transfer is at the outer side of the annulus
3. when the fluid is a liquid and heat transfer is at the inner side of the annulus
11.10.26The system shall be able to compute the average wall temperature and store it as a material property.
11.10.27The system shall be able to compute the average wall temperature and store it as a material property even with null wall heat transfer coefficients,
11.10.28The system shall report an error if the number of wall heat transfer coefficients does not match the number of wall temperatures when computing average wall temperatures as material properties.
11.10.29The system shall report an error if the number of wall heated perimeters does not match the number of wall temperatures when computing average wall temperatures as material properties.
11.10.30The system shall be able to compute the convective heat transfer coefficient from the Nusselt number and the hydraulic diamter, as a material property
11.10.31The system shall be able to compute the Prandtl number as a material property.
11.10.32The system shall be able to compute the Reynolds number as a material property.
11.10.33The system shall return a warning message when the Cheng-Todreas correlation is used with a Pitch-to-Diameter ration above 1.50.
11.10.34The system shall compute the friction factor using the Cheng-Todreas correlation with different subchannel configurations.
11.10.35The system shall be able to compute the wall friction factor using the Churchill correlation.
11.10.36The system shall be able to compute the wall friction factor using the Churchill correlation with automatic differentiation.
11.10.37The system shall be able to compute the wall heat transfer coefficient using the Dittus Boelter correlation.
11.10.38The system shall be able to rename the wall heat transfer coefficient computed with the Dittus Boelter correlation.

thermal_hydraulics: Misc
11.11.1The system shall be able to use adaptive mesh refinement in a 1D single phase compressible flow simulation.
11.11.2The system shall be able to automatically count the number of solve iterations as a debugging feature.
11.11.3The system shall be able to couple two 1D single phase compressible flow simulations using non overlapping coupling set up using multiple applications.
11.11.4The system shall be able to use mesh displacement with components.
11.11.5The system shall be able to produce an exodus file for setting initial conditions in flow channels
11.11.6The system shall be able to use an exodus file for setting initial conditions in flow channels
11.11.7The system shall report an error when a block is non found in the restart ExodusII file
11.11.8The system shall be able to produce an exodus file for setting initial conditions in heat structures
11.11.9The system shall be able to use an exodus file for setting initial conditions in heat structures
11.11.10The system shall be able to produce an exodus file for setting initial conditions in 3D heat structures
11.11.11The system shall be able to use an exodus file for setting initial conditions in 3D heat structures
11.11.12The system shall be able to produce an exodus file for setting initial conditions in a heat structure and a connected flow channel
11.11.13The system shall be able to use an exodus file for setting initial conditions in a heat structure and a connected flow channel.
11.11.14The system shall be able to produce an exodus file for setting initial conditions in heat transfer from 3D heat structures
11.11.15The system shall be able to use an exodus file for setting initial conditions in heat transfer from 3D heat structures
11.11.16The system shall be able to produce an exodus file for setting initial conditions in shaft
11.11.17The system shall be able to use an exodus file for setting initial conditions in shaft
11.11.18The system shall be able to produce an exodus file for setting initial conditions in volume junctions
11.11.19The system shall be able to use an exodus file for setting initial conditions in volume junctions
11.11.20The system shall report an error if one tries to use an exodus file for setting initial conditions in a volume junction, with parallel threads.
11.11.21The system shall be able to only output the components' mesh and avoid running the rest of the simulation.
11.11.22The system shall be able to create a checkpoint for restarting a single phase compressible flow simulation.
11.11.23The system shall be able to restart from a checkpoint in a single phase compressible flow simulation.
11.11.24The system shall be able to restart from a checkpoint in a single phase compressible flow simulation, and override some of the restarted values with initial conditions.
11.11.25The system shall be able to generate a power profile in an Exodus file to be read from a 1D flow simulation.
11.11.26The system shall be able to read a power profile from an Exodus file to apply on components in a 1D single phase compressible flow simulation.
11.11.27The system shall uniform refine mesh when specifid on the command line

thermal_hydraulics: Output
11.12.1The system shall be able to disable the output of scalar variables to the console.
11.12.2The system shall be able to allow the output of scalar variables to the console.
11.12.3The system shall be able to create an annotation map for components to be read when visualizing output with Paraview.
11.12.4The system shall be able to output vector velocities, either as a vector or scalar variables, notably to view velocity in exodus files.

thermal_hydraulics: Postprocessors
11.13.1This system shall compute an RZ integral of a material property.
11.13.2The system shall be able to compute a component of the flux vector at a boundary in 1D single phase compressible flow simulations.
11.13.3The system shall be able to compute a component of the flux vector at a junction in 1D single phase compressible flow simulations.
11.13.4The system should report an error when users set subdomain-restricted RZ-symmtrical THM-specific objects on RZ-subdomains.
11.13.5The system shall be able to integrate the values of a function on a side, assuming cylindrical coordinates in a Cartesian frame of reference.
11.13.6The system should error out when users set boundary-restricted RZ-symmtrical THM-specific objects on RZ-subdomains.
11.13.7The system shall compute the heat conduction rate across an RZ boundary.
11.13.8The system shall be able to compute the convective heat flux rate on a boundary.
11.13.9The system shall be able to compute the convective heat flux rate on a boundary in a single phase simulation.
11.13.10The system shall be able to compute the convective heat flux rate on a boundary in a single phase simulation, using cylindical coordinates in a Cartesian frame of reference.
11.13.11The system shall be able to compute the convective heat flux rate on a boundary in a single phase simulation, using cylindical coordinates in a Cartesian frame of reference, with an external temperature and a heat transfer coefficient computed by an external application.
11.13.12The system shall compute the heat rate for a user-provided heat flux function.
11.13.13The system shall compute the heat rate for a user-provided heat flux function for a cylindrical boundary.
11.13.14The system shall be able to compute a radiative heat flux on a boundary.
11.13.15The system shall be able to compute a radiative heat flux on a boundary, using cylindrical coordinates in a Cartesian frame of reference.
11.13.16The system shall be able to compute the energy stored on a plate heat structure.
11.13.17The system shall be able to compute the energy stored on a plate heat structure with a reference temperature for the energy.
11.13.18The system shall be able to compute the energy stored on a cylindrical heat structure.
11.13.19The system shall report an error if a component parameter is selected for output but that parameter or that component does not exist.
11.13.20The system shall provide a post-processor to retrieve the torque and moment of inertia from a shaft-connected component.
11.13.21The system shall be able to compute a diffusive flux on a boundary, using cylindrical coordinates in a Cartesian frame of reference.
11.13.22The system shall compute specific impulse from conditions on a boundary

thermal_hydraulics: Problems
11.14.1
The system shall be able to model an abrupt area change in a liquid flow
1. with a junction.
2. without a junction.
11.14.2The system shall be able to simulate 1D single phase compressible flow in a channel with an area constriction.
11.14.3The system shall be able to simulate 1D single phase compressible flow in a channel with an area constriction, modeled using a junction between two components of different areas.
11.14.4The system shall be able to model an open Brayton cycle
11.14.5The system shall be able to model a closed Brayton cycle
11.14.6The system shall be able to model an open recuperated Brayton cycle
11.14.7The system shall be able to solve with 1D single phase compresible flow a Riemann problem with a double rarefaction solution.
11.14.8The system shall be able to simulate fluid free fall in a channel with 1D single phase compressible flow.
11.14.9
The system shall produce an accurate solution to the Lax shock tube benchmark problem
1. using an explicit temporal discretization, and
2. using an implicit temporal discretization.
11.14.10The system shall be able to compute the convergence order of its 1D single phase compressible flow discretization.
11.14.11
The system shall simulate a natural circulation loop using flow channels and
1. one-to-one junctions.
2. volume junctions.
11.14.12
The system shall compute a pressure drop solution
1. without a junction, and
2. with a junction.
11.14.13The system shall be able to solve the Sedov blast wave problem using a 1D single phase compressible flow formulation.
11.14.14The system shall be able to solve the Sod shock wave problem using a 1D single phase compressible flow formulation.
11.14.15The system shall be able to solve the Sod shock wave problem using a 1D single phase compressible flow formulation for a few time steps.
11.14.16The system shall be able to solve the Sod shock wave problem using a 1D single phase compressible flow formulation when the shock tube is not aligned with the X axis.
11.14.17The system shall be able to solve the Sod shock wave problem using a 1D single phase compressible flow formulation using a first order time integration scheme and a Newton nonlinear solver.
11.14.18The system shall be able to solve a square wave problem with a 1D single phase compressible flow discretization with a minmod flux limiter.
11.14.19The system shall be able to solve a square wave problem with a 1D single phase compressible flow discretization with no flux limiter.
11.14.20The system shall be able to solve a square wave problem with a 1D single phase compressible flow discretization with a MC flux limiter.
11.14.21The system shall be able to solve a square wave problem with a 1D single phase compressible flow discretization with a Superbee flux limiter.
11.14.22The system shall be able to model a 3-pipe shock.
11.14.23The system shall be able to simulate a water hammer with 1D single phase compressible flow.
11.14.24The system shall be able to model an open, 3-pipe shock tube.
11.14.25The system shall be able to model a closed, 4-pipe shock tube.
11.14.26The system shall be able to solve the Woodward Colebella blast wave problem with 1D single phase compressible flow.

thermal_hydraulics: Scalarkernels
11.15.1The system shall be able to add a time derivative to a scalar ordinary differential equation.
11.15.2The system shall be able to add source term in an ordinary differential equation, computed from a postprocessor.

thermal_hydraulics: Userobjects
11.16.1The system shall be able to integral a function in a dedicated element loop.
11.16.2The system shall be able to compute layered averages along a boundary, using cylindrical coordinates in a Cartesian frame of reference.
11.16.3The system shall allow computing changes in channel flow areas from deformation.

thermal_hydraulics: Utils
11.17.1The system shall be able to output warnings in a batch.
11.17.2The system shall be able to output errors in a batch.
11.17.3The system shall be able to compute a smooth cubic transition between two functions of a variable.
11.17.4The system shall be able to compute a smooth weighted transition between two functions of a variable.
11.17.5The system shall be able to compute a numerically accurate Jacobian when performing a smooth cubic transition between two functions of a variable, showing that derivatives were computed accurately.
11.17.6The system shall be able to compute a numerically accurate Jacobian when performing a smooth weighted transition between two functions of a variable, showing that derivatives were computed accurately.
11.17.7The system shall be able to compute a smooth cubic transition between two functions of a variable and conserving derivatives with automatic differentiation.
11.17.8The system shall be able to compute a smooth weighted transition between two functions of a variable and conserving derivatives with automatic differentiation.

thermal_hydraulics: Vectorpostprocessors
11.18.1The system shall provide a vector post-processor to sample regular material properties in one or more blocks.
11.18.2The system shall provide a vector post-processor to sample AD material properties in one or more blocks.
11.18.3The system shall report an error if a non-existent material property is requested for the block material property sampler vector post-processor.
11.18.4The system shall be able to sample a vector material property in a 1D mesh.

Usability Requirements

No requirements of this type exist for this application, beyond those of its dependencies.

Performance Requirements

No requirements of this type exist for this application, beyond those of its dependencies.

System Interfaces

No requirements of this type exist for this application, beyond those of its dependencies.

System Operations

Human System Integration Requirements

The Thermal Hydraulics module is command line driven and conforms to all standard terminal behaviors. Specific human system interaction accommodations shall be a function of the end-user's terminal. MOOSE (and therefore the Thermal Hydraulics module) does support optional coloring within the terminal's ability to display color, which may be disabled.

Maintainability

The latest working version (defined as the version that passes all tests in the current regression test suite) shall be publicly available at all times through the repository host provider.
Flaws identified in the system shall be reported and tracked in a ticket or issue based system. The technical lead will determine the severity and priority of all reported issues and assign resources at their discretion to resolve identified issues.
The software maintainers will entertain all proposed changes to the system in a timely manner (within two business days).
The core software in its entirety will be made available under the terms of a designated software license. These license terms are outlined in the LICENSE file alongside the Thermal Hydraulics module source code. As a MOOSE physics module, the license for the Thermal Hydraulics module is identical to that of the framework - that is, the LGPL version 2.1 license.

Reliability

The regression test suite will cover at least 90% of all lines of code within the Thermal Hydraulics module at all times. Known regressions will be recorded and tracked (see Maintainability) to an independent and satisfactory resolution.

System Modes and States

MOOSE applications normally run in normal execution mode when an input file is supplied. However, there are a few other modes that can be triggered with various command line flags as indicated here:

Command Line Flag	Description of mode
`-i <input_file>`	Normal execution mode
`--split-mesh <splits>`	Read the mesh block splitting the mesh into two or more pieces for use in a subsequent run
`--use-split`	(implies -i flag) Execute the simulation but use pre-split mesh files instead of the mesh from the input file
`--yaml`	Output all object descriptions and available parameters in YAML format
`--json`	Output all object descriptions and available parameters in JSON format
`--syntax`	Output all registered syntax
`--registry`	Output all known objects and actions
`--registry-hit`	Output all known objects and actions in HIT format
`--mesh-only` (implies -i flag)	Run only the mesh related tasks and output the final mesh that would be used for the simulation
`--start-in-debugger <debugger>`	Start the simulation attached to the supplied debugger

note

The list of system-modes may not be extensive as the system is designed to be extendable to end-user applications. The complete list of command line options for applications can be obtained by running the executable with zero arguments. See the command line usage.

Physical Characteristics

The Thermal Hydraulics module is software only with no associated physical media. See System Requirements for a description of the minimum required hardware necessary for running the Thermal Hydraulics module.

Environmental Conditions

Not Applicable

System Security

MOOSE-based applications such as the Thermal Hydraulics module have no requirements or special needs related to system security. The software is designed to run completely in user-space with no elevated privileges required nor recommended.

Information Management

The core framework and all modules in their entirety will be made publicly available on an appropriate repository hosting site. Day-to-day backups and security services will be provided by the hosting service. More information about MOOSE backups of the public repository on INL-hosted services can be found on the following page: GitHub Backups

Polices and Regulations

MOOSE-based applications must comply with all export control restrictions.

System Life Cycle Sustainment

MOOSE-based development follows various agile methods. The system is continuously built and deployed in a piecemeal fashion since objects within the system are more or less independent. Every new object requires a test, which in turn requires an associated requirement and design description. The Thermal Hydraulics module development team follows the NQA-1 standards.

Packaging, Handling, Shipping and Transportation

No special requirements are needed for packaging or shipping any media containing MOOSE and Thermal Hydraulics module source code. However, some MOOSE-based applications that use the Thermal Hydraulics module may be export-controlled, in which case all export control restrictions must be adhered to when packaging and shipping media.

Verification

The regression test suite will employ several verification tests using comparison against known analytical solutions, the method of manufactured solutions, and convergence rate analysis.

Introduction
System Overview
References
Definitions and Acronyms
System Requirements
Verification