MOOSE (Multiphysics Object Oriented Simulation Environment) is an

object-oriented Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of pro ...

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

finite element framework for the development of tightly coupled

multiphysics In computational modelling, multiphysics simulation (often shortened to simply "multiphysics") is defined as the simultaneous simulation of different aspects of a physical system or systems and the interactions among them. For example, simultaneous ...

solvers from

Idaho National Laboratory Idaho National Laboratory (INL) is one of the national laboratories of the United States Department of Energy and is managed by the Battelle Energy Alliance. While the laboratory does other research, historically it has been involved with nu ...

. MOOSE makes use of the PETSc non-linear solver package and libmesh to provide the finite element discretization. A key design aspect of MOOSE is the decomposition of weak form residual equations into separate terms that are each represented by compute kernels. The combination of these kernels into complete residuals describing the problem to be solved is performed at run time. This allows modifications such as toggling of mechanisms and the addition of new physics without recompilation. MOOSE comes with an extensive library of kernels providing residual terms for

solid mechanics Solid mechanics, also known as mechanics of solids, is the branch of continuum mechanics that studies the behavior of solid materials, especially their motion and deformation under the action of forces, temperature changes, phase changes, and ot ...

Navier–Stokes equations In physics, the Navier–Stokes equations ( ) are partial differential equations which describe the motion of viscous fluid substances, named after French engineer and physicist Claude-Louis Navier and Anglo-Irish physicist and mathematician Geo ...

phase field models A phase-field model is a mathematical model for solving interfacial problems. It has mainly been applied to solidification dynamics, but it has also been applied to other situations such as viscous fingering, fracture mechanics, hydrogen embrittleme ...

and more. MOOSE uses

VTK The Visualization Toolkit (VTK) is an open-source software system for 3D computer graphics, image processing and scientific visualization.''Visualization Handbook'', Academic Press, 2005, Chapter 30: the Visualization Toolkit/ref> VTK is distrib ...

Background

The development of MOOSE at

(INL), beginning in May 2008, has resulted in a unique approach to computational engineering that combines

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

with a strong underlying mathematical description in a unique way that allows scientists and engineers to develop engineering

simulation A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model, models; the model represents the key characteristics or behaviors of the selected system or proc ...

tools in a fraction of the time previously required. The heart of MOOSE is the Kernel. A Kernel is a "piece" of

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

. To add new physics to an application built using MOOSE, all that is required is to supply a new Kernel that describes the discrete form of the equation. It's usually convenient to think of a Kernel as a

mathematical operator In mathematics, an operator is generally a mapping or function that acts on elements of a space to produce elements of another space (possibly and sometimes required to be the same space). There is no general definition of an ''operator'', but ...

, such as a

Laplacian In mathematics, the Laplace operator or Laplacian is a differential operator given by the divergence of the gradient of a scalar function on Euclidean space. It is usually denoted by the symbols \nabla\cdot\nabla, \nabla^2 (where \nabla is the ...

or a

convection Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convec ...

term in a

partial differential equation In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a Multivariable calculus, multivariable function. The function is often thought of as an "unknown" to be sol ...

(PDE). Kernels may be swapped or coupled together to achieve different application goals. These Kernels, which now number in the hundreds, allow a

scientist A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branches of science, area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, ...

engineer Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the l ...

to develop an application rapidly. For a new application, existing Kernels are selected as-is, or modified as necessary, and "plugged" in. An

advection In the field of physics, engineering, and earth sciences, advection is the transport of a substance or quantity by bulk motion of a fluid. The properties of that substance are carried with it. Generally the majority of the advected substance is al ...

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

reaction Reaction may refer to a process or to a response to an action, event, or exposure: Physics and chemistry *Chemical reaction *Nuclear reaction *Reaction (physics), as defined by Newton's third law *Chain reaction (disambiguation). Biology and me ...

equation is of the same mathematical form no matter what application it is being used for. Typically, only the form of the coefficients or the dependencies on other physics need to be defined; rarely must complete Kernels be constructed from scratch. With MOOSE, only the Kernel development is required from the scientist or engineer (

application developer A computer programmer, sometimes referred to as a software developer, a software engineer, a programmer or a coder, is a person who creates computer programs — often for larger computer software. A programmer is someone who writes/creates ...

). MOOSE is designed to do everything else for the application developer, such as finite element

discretization In applied mathematics, discretization is the process of transferring continuous functions, models, variables, and equations into discrete counterparts. This process is usually carried out as a first step toward making them suitable for numerical ...

of the PDEs, the nonlinear solver, and the parallel

high performance computing High-performance computing (HPC) uses supercomputers and computer clusters to solve advanced computation problems. Overview HPC integrates systems administration (including network and security knowledge) and parallel programming into a multid ...

. The idea of naming MOOSE-based applications after

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

indigenous Indigenous may refer to: *Indigenous peoples *Indigenous (ecology), presence in a region as the result of only natural processes, with no human intervention *Indigenous (band), an American blues-rock band *Indigenous (horse), a Hong Kong racehorse ...

animal species is loosely based on

Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, ...

's 1970s – 1990s approach to naming their codes after Native American tribes and artifacts, such as APACHE, CONCHAS, and the

KIVA A kiva is a space used by Puebloans for rites and political meetings, many of them associated with the kachina belief system. Among the modern Hopi and most other Pueblo peoples, "kiva" means a large room that is circular and underground, ...

series of codes. There are now over twenty MOOSE-based application animals in various stages of development, ranging from recently obtaining preliminary results to being nationally recognized as

state-of-the-art The state of the art (sometimes cutting edge or leading edge) refers to the highest level of general development, as of a device, technique, or scientific field achieved at a particular time. However, in some contexts it can also refer to a level ...

efforts (such as BISON and MARMOT for fuels performance modeling & simulation activities).

Description

Multiphysics Object-Oriented Simulation Environment (MOOSE)

MOOSE is a development and run-time environment for the solution of multi-physics systems that involve multiple physical models or multiple simultaneous physical phenomena. The systems are generally represented (modeled) as a system of fully coupled nonlinear partial differential equation systems (an example of a multi-physics system is the thermal feedback effect upon neutronics cross-sections where the cross-sections are a function of the

heat transfer Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...

). Inside MOOSE, the Jacobian-Free Newton Krylov (JFNK) method is implemented as a parallel nonlinear solver that naturally supports effective coupling between physics equation systems (or Kernels). The physics Kernels are designed to contribute to the nonlinear residual, which is then minimized inside of MOOSE. MOOSE provides a comprehensive set of

finite element The finite element method (FEM) is a popular method for numerically solving differential equations arising in engineering and mathematical modeling. Typical problem areas of interest include the traditional fields of structural analysis, heat t ...

support capabilities (libMesh) and provides for mesh adaptation and parallel execution. The framework heavily leverages

software libraries In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subro ...

from the

Department of Energy A Ministry of Energy or Department of Energy is a government department in some countries that typically oversees the production of fuel and electricity; in the United States, however, it manages nuclear weapons development and conducts energy-rel ...

(DOE) and the

National Nuclear Security Administration The National Nuclear Security Administration (NNSA) is a United States federal agency responsible for safeguarding national security through the military application of nuclear science. NNSA maintains and enhances the safety, security, and e ...

(NNSA), such as the nonlinear solver capabilities in either the Portable, Extensible Toolkit for Scientific Computation ( PETSc) project or the

Trilinos Trilinos is a collection of open-source software, open-source software libraries, called ''packages'', intended to be used as building blocks for the development of scientific applications. The word "Trilinos" is Greek and conveys the idea of "a st ...

project.

ELK (Extended Library of Kernels)

ELK is a library for common Kernels, boundary conditions and material base classes.

YAK (Yet Another Kernel)

YAK is a library of common actions, Kernels, boundary conditions, and material base classes for radiation transport applications. YAK is currently linked with RattleSnake (multi-group radiation Sn transport), Pronghorn (multi-group diffusion), and Critter (multi-length scale temperature feedback).

Applications

BISON

BISON was the first MOOSE-based application "animal," and is a finite element-based nuclear fuel performance code applicable to a variety of fuel forms including

light water reactor The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron reacto ...

fuel rods,

TRISO Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing ...

fuel particles, and metallic rod and plate fuel. It solves the fully coupled equations of thermomechanics and species diffusion and includes important fuel physics such as fission gas release and material property degradation with burnup. BISON is based on the MOOSE framework and can therefore efficiently solve problems on either

two-dimensional In mathematics, a plane is a Euclidean (flat), two-dimensional surface that extends indefinitely. A plane is the two-dimensional analogue of a point (zero dimensions), a line (one dimension) and three-dimensional space. Planes can arise as s ...

axisymmetric Rotational symmetry, also known as radial symmetry in geometry, is the property a shape has when it looks the same after some rotation by a partial turn. An object's degree of rotational symmetry is the number of distinct orientations in which i ...

three-dimensional Three-dimensional space (also: 3D space, 3-space or, rarely, tri-dimensional space) is a geometric setting in which three values (called ''parameters'') are required to determine the position of an element (i.e., point). This is the informal ...

geometries using standard workstations or large high performance computers.

Plasticity Plasticity may refer to: Science * Plasticity (physics), in engineering and physics, the propensity of a solid material to undergo permanent deformation under load * Neuroplasticity, in neuroscience, how entire brain structures, and the brain it ...

, irradiation growth, and thermal and irradiation creep models are implemented for clad materials. Models are also available to simulate gap heat transfer, mechanical contact, and the evolution of the gap/

plenum Plenum may refer to: * Plenum chamber, a chamber intended to contain air, gas, or liquid at positive pressure * Plenism, or ''Horror vacui'' (physics) the concept that "nature abhors a vacuum" * Plenum (meeting), a meeting of a deliberative assem ...

pressure with plenum volume, gas temperature, and fission gas addition. BISON is also coupled to a MOOSE-based mesoscale phase field material property simulation capability.

MARMOT

MARMOT is a finite element-based phase field code for modeling irradiation-induced

microstructure Microstructure is the very small scale structure of a material, defined as the structure of a prepared surface of material as revealed by an optical microscope above 25× magnification. The microstructure of a material (such as metals, polymers ...

evolution. MARMOT predicts the effect of

radiation damage Radiation damage is the effect of ionizing radiation on physical objects including non-living structural materials. It can be either detrimental or beneficial for materials. Radiobiology is the study of the action of ionizing radiation on living ...

on microstructure evolution, including void

nucleation In thermodynamics, nucleation is the first step in the formation of either a new thermodynamic phase or structure via self-assembly or self-organization within a substance or mixture. Nucleation is typically defined to be the process that deter ...

and growth, bubble growth,

grain boundary In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and thermal ...

migration, and gas diffusion and segregation. The phase field equations can be coupled with heat conduction and

from ELK to consider the effect of temperature and stress gradients on the evolution. In addition, MARMOT calculates the effect of the microstructure evolution on various bulk material properties, including

thermal conductivity The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...

and

porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...

. Once the bulk properties have been calculated, they can be passed to BISON for a fuel performance simulation. This coupling between MARMOT and BISON has been achieved in the hybrid code BARMOT.

FALCON

FALCON is being developed to enable simulation of the tightly coupled fluid-rock behavior in

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

and engineered geothermal system (EGS)

reservoirs A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

, targeting the dynamics of fracture stimulation, fluid flow, rock deformation, and heat transport in a single integrated code, with the ultimate goal of providing a tool that can be used to test the viability of EGS in the United States and worldwide. Reliable reservoir performance predictions of EGS systems require accurate and robust modeling for the coupled thermal-hydrological-mechanical processes. Conventionally, these types of problems are solved using

operator splitting This is a list of operator splitting topics. General *Alternating direction implicit method — finite difference method for parabolic, hyperbolic, and elliptic partial differential equations * GRADELA — simple gradient elasticity model * Matrix ...

methods, usually by coupling a subsurface flow and heat transport simulator with a

simulator via input files. FALCON eliminates the need for using operator splitting methods to simulate these systems, and the scalability of MOOSE supported applications allows for simulating these tightly coupled processes at the reservoir scale, allowing for examination of the system as a whole (something the operator splitting methodologies generally cannot do).

RAT

ReActive Transport (RAT) has been developed to solve reactive transport problems in subsurface

porous media A porous medium or a porous material is a material containing pores (voids). The skeletal portion of the material is often called the "matrix" or "frame". The pores are typically filled with a fluid (liquid or gas). The skeletal material is usua ...

that involves highly nonlinearly coupled physical processes of

fluid flow In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) an ...

solute In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. If the attractive forces between the solvent ...

transport,

biogeochemical Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the cryosphere, t ...

reactions and media-solution interactions. These problems are common in various subsurface-engineered systems, such as engineered

environmental remediation Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. Remedial action is generally subject to an array of regulatory requirements, and may al ...

, enhanced geothermal systems and carbon dioxide geological sequestration. Currently, the physics that could be coupled in RAT include: single-phase fluid flow in porous media,

, dispersion and diffusion transport, aqueous kinetic reaction, aqueous equilibrium reaction, kinetic mineral precipitation/dissolution reaction, and Carmen-Kozeny porosity-permeability relationship. This software is not to be confused with the Reactor Analysis Tool (RAT) which is a toolkit based on ROOT and GEANT4 for microphysical simulations of scintillation detectors used in neutrino and dark matter experiments including Braidwood, SNO+, and DEAP-3600.

RELAP-7

RELAP-7 is the next-generation tool in the RELAP safety/systems analysis application series and is based upon the MOOSE development and

runtime environment In computer programming, a runtime system or runtime environment is a sub-system that exists both in the computer where a program is created, as well as in the computers where the program is intended to be run. The name comes from the compile t ...

framework. RELAP-7 will retain and improve the basic analysis capability of RELAP5. The four major improvements are 1) A well-posed seven-equation two-phase flow model (liquid, gas, and interface pressures) versus the obsolete ill-posed six-equation flow model (non-physical mixture sound speed) found in RELAP5; 2) Improved numerical approximations resulting in second-order accuracy in both space and time versus the first order approximations in RELAP5; 3) Implicit tightly coupled time integration for long duration transients, such as providing plant behavior for full life fuel cycle evaluations; and 4) the ability to easily couple to multi-dimensional core simulators being developed in other programs (NEAMS, CASL, ATR LEP).

Pronghorn

Pronghorn was originally developed for simulation of the gas-cooled pebble-bed

VHTR A high-temperature gas-cooled reactor (HTGR), is a nuclear reactor that uses a graphite moderator with a once-through uranium fuel cycle. The HTGR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of ...

concept. The current capabilities of Pronghorn include transient and steady coupled porous fluid flow and solid-state heat conduction with a standard multi-group diffusion model (i.e., fixed-source, criticality, and time-dependent). Recently added capabilities include a nonlinear acceleration scheme for criticality problems and a simple thermal-fluid model for the prismatic reactor concept. Future capabilities will include a more advanced multi-phase flow type of model (to study thermal boundary layer effects) and a radiation transport model. The physics can be solved in three-dimensional

Cartesian Cartesian means of or relating to the French philosopher René Descartes—from his Latinized name ''Cartesius''. It may refer to: Mathematics *Cartesian closed category, a closed category in category theory *Cartesian coordinate system, modern ...

(x, y, z) or cylindrical ( r, q, z) space, with precursor and adiabatic thermal feedback models. This code has been validated against the PBMR400 benchmark problem. Using Pronghorn, rod ejection simulations have been conducted for thermal-fluids/neutronics for both pebble-bed and prismatic gas-cooled reactors and simple thermal-neutronics coupled LWR benchmark problems.
/ref>

Features

* Fully coupled, fully implicit multiphysics solver * Dimension independent physics * Automatically parallel (largest runs >100,000 CPU cores) * Modular development simplifies code reuse * Built-in mesh adaptivity * Continuous and Discontinuous Galerkin (DG) (at the same time) * Forward-mode automatic differentiation for Jacobian matrix computation * Intuitive parallel multiscale solves (see videos below) * Dimension agnostic, parallel geometric search (for contact related applications) * Flexible, pluggable graphical user interface * ~30 pluggable interfaces allow specialization of every part of the solve

Notes

References

* * * L. Guo, H. Huang, D. Gaston, and G. Redden. "Modeling of calcite precipitation driven by bacteria-facilitated urea hydrolysis in a flow column using a fully coupled, fully implicit parallel reactive transport simulator". In Eos Transactions American Geophysical Union, 90(52), Fall Meeting Supplement, AGU 90(52), San Francisco, CA, Dec 14-18 2009. * *

External links

MOOSE Homepage

Idaho National Laboratory's Technology Deployment Office
*
MOOSE publications
- List of publications on the MOOSE framework. {{DEFAULTSORT:MOOSE (Multiphysics Object Oriented Simulation Environment) C++ software Computational fluid dynamics Computer-aided engineering software for Linux Finite element software Free software programmed in C++ Idaho National Laboratory Industrial software Nuclear reactors Physics software Scientific simulation software Software that uses VTK