Level Set 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 Level Set module.

Framework System Requirements Specification

Introduction

System Purpose

The purpose of the MOOSE Level Set module is to provides basic functionality to solve the level set equation. The Level Set module can be very easily coupled with other physics modules in MOOSE. The level set method has become popular in many disciplines, such as image processing, computer graphics, computational geometry, optimization, computational fluid dynamics, and computational biology.

System Scope

The MOOSE Level Set module provides capabilities for solving a set of level set equations. The level set method is commonly used for front tracking problems. The advection of the level set equation is solved using the Galerkin finite element method, and is stabilized with streamline Upwind/Petrov-Galerkin method. To preserve the smooth profile of the regularized level set variable, a re-initialization step can be used through the MOOSE multi-app system. The solutions are verified against classical benchmark problems.

System Overview

System Context

The Level Set 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 Level Set 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 Level Set module and other MOOSE-based applications.

System Functions

Since the Level Set 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 Level Set 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 Level Set module:

Level Set module Developers: These are the core developers of the Level Set 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 Level Set 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 Level Set 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 Level Set module is developed using MOOSE and can itself be based on various MOOSE modules, as such the SRS for the Level Set 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 Level Set module is designed with the fewest possible constraints on hardware and software. For more context on this point, the Level Set module SRS defers to the framework Assumptions and Dependencies.

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"
}

Elin Olsson and Gunilla Kreiss. A conservative level set method for two phase flow. Journal of computational physics, 210(1):225–246, 2005. URL: http://dx.doi.org/10.1016/j.jcp.2005.04.007.

@article{olsson2005conservative,
    author = "Olsson, Elin and Kreiss, Gunilla",
    title = "A conservative level set method for two phase flow",
    journal = "Journal of computational physics",
    volume = "210",
    number = "1",
    pages = "225--246",
    year = "2005",
    publisher = "Elsevier",
    url = "http://dx.doi.org/10.1016/j.jcp.2005.04.007"
}

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

level_set: Functions
8.1.1The level set module shall include the bubble function defined in Olsson and Kreiss (2005).
8.1.2The Olsson bubble function shall return correct derivatives for dual number points.
8.1.3The level set module shall include the plane function defined in Olsson and Kreiss (2005).
8.1.4The level set module shall include the vortex function defined in Olsson and Kreiss (2005) with an instantaneous reverse feature.
8.1.5The level set module shall include the vortex function defined in Olsson and Kreiss (2005) with an cosine reverse feature.

level_set: Kernels
8.2.1The LevelSetAdvection Kernel shall converage at the correct rate as tested by the method of manufactured solutions.
8.2.2The level set module shall include the reinitialization scheme presented by Olsson and Kreiss (2005).

level_set: Reinitialization
8.3.1The level set module shall be capable of solving the level set equation with original reinitialization.
8.3.2The level set module shall be capable of solving the level set equation with modified reinitialization.

level_set: Transfers
8.4.1The level set module shall include the ability to transfer a non-linear variable between the parent and a sub-application.
8.4.2The level set module shall include the ability to transfer refinement patterns, with multiple levels of refinement, to a sub-application.
8.4.3The level set module shall include the ability to transfer refinement patterns, with a single level of refinement, to a sub-application.
8.4.4The system shall return an error if parameters for an unsupported direction are passed to a transfer

level_set: Verification
8.5.1The level set module shall use the method of manufactured solutions to test convergence of the level set equation and ensure that the level 0 solution is consistent.
8.5.2The level set module shall use the method of manufactured solutions to test convergence of the level set equation and ensure that the level 1 solution is consistent.
8.5.3The level set module shall use the method of manufactured solutions to test convergence of the level set equation and ensure that the level 2 solution is consistent.
8.5.4The level set module shall use the method of manufactured solutions to test convergence of the level set equation and ensure that the level 3 solution is consistent.
8.5.5The level set module shall use the method of manufactured solutions to test convergence of the level set equation and ensure that the level 4 solution is consistent.
8.5.6The level set module shall use the method of manufactured solutions to test convergence of the level set equation with SUPG and ensure that the level 0 solution is consistent.
8.5.7The level set module shall use the method of manufactured solutions to test convergence of the level set equation with SUPG and ensure that the level 1 solution is consistent.
8.5.8The level set module shall use the method of manufactured solutions to test convergence of the level set equation with SUPG and ensure that the level 2 solution is consistent.
8.5.9The level set module shall use the method of manufactured solutions to test convergence of the level set equation with SUPG and ensure that the level 3 solution is consistent.
8.5.10The level set module shall use the method of manufactured solutions to test convergence of the level set equation with SUPG and ensure that the level 4 solution is consistent.

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 Level Set 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 Level Set 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 Level Set module source code. As a MOOSE physics module, the license for the Level Set 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 94% of all lines of code within the Level Set 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 Level Set module is software only with no associated physical media. See System Requirements for a description of the minimum required hardware necessary for running the Level Set module.

Environmental Conditions

Not Applicable

System Security

MOOSE-based applications such as the Level Set 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 Level Set 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 Level Set module source code. However, some MOOSE-based applications that use the Level Set 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