AnalyticMGOpac: An analytic opacity integrator for multigroup calculations

This C++14 code numerically integrates the opacity formulas for the test problem described in

• Thomas A. Brunner, "A Family of Multi-Dimensional Thermal Radiative Transfer Test Problems", 2023, LLNL-TR-858450-REV-1, DOI 10.2172/2280904

Please see that document for a full description.

Getting started

This code mainly consists of two implementation files for the opacity and integrator. The there is a test file that will output sample data used in LLNL-TR-858450 and a Python file to make the plots.

• AnalyticEdgeOpacity.cc and AnalyticEdgeOpacity.hh: C++14 code to compute the frequency dependent opacity for a given set of parameters
• MultiGroupIntegrator.cc and MultiGroupIntegrator.hh: C++14 code to integrate a given instance of AnalyticEdgeOpacity for a particular set of group bounds.
• opacTest.cc: An optional C++20 test driver. This language version was chosen to help reduce some boilerplate in order to help make it clearer how to use the library.
• Makefile: A simple makefile to build the test driver, assuming you have clang++ installed.
• plotOpacs.py: A matplotlib based script to plot the results from opacTest.cc which can be seen in LLNL-TR-858450.

Prerequisites

The opacity integrator only requires C++14. The test file opacTest.cc which documents the usage of the integrator relies on the {fmt} library.

Installing

A simple Makefile is included for this project. You can edit it to fit your compiler.

git clone [email protected]:fmtlib/fmt.git
make

Running the tests

After building the test code, you can generate opacity plots by running

% ./opacTest
% python3 plotOpacs.py

Release

The code of this site is released under the MIT License. For more details, see the LICENSE file. All new contributions must be made under this license.

See the NOTICE file for other important information.

LLNL-CODE-858992