Orion is a Navier-Stokes solver written in Python. It uses finite-difference method for calculating spatial derivatives and parallelized geometric multigrid method for solving the pressure Poisson equation.
The solver is written in separate modules, which are listed below:
main.py- This is the main file which needs to be executed to run the solver.fluidSolverNU.py- This is the solver called by main when computing hydrodynamics simulation on non-uniform grids.fluidSolverUG.py- This is the solver called by main when computing hydrodynamics simulation on uniform grids.globalVars.py- All the global parameters which the user needs to set are contained in this file.calculateFD.py- This module contains the functions to compute first and second derivatives of field variables.meshData.py- Grid data, like coordinates of collocated and staggered points, and grid transformation metrics are stored in this module.poissonSolverNU.py- The geometric multi-grid solver used to compute pressure correction on non-uniform grids is written in this module.poissonSolverUG.py- The geometric multi-grid solver used to compute pressure correction on uniform grids is written in this module.writeData.py- This module offers options to write solution data in either ASCII or HDF5 format.boundaryConditions.py- The boundary conditions to be applied on velocity and pressure are written in this module.vortexLES.py- The stretched spiral vortex LES model is implemented in this module to compute sub-grid stress terms.
To install Orion, you need to first clone the git repository into your local machine
git clone https://github.com/roshansamuel/orion.git
Orion is compatible with Python3, and can be executed by one of the following commands at the root folder of the solver, in the terminal.
./main.py
or
python main.py
Before executing the solver, please set the appropriate parameters for the Navier-Stokes problem by editing the globalVars.py file.
Brief descriptions of the parameters are given in comments within the file.
Please make sure that the following Python modules are installed before executing the solver.
numpy- All array manipulations are performed using NumPyh5py- Solution files can be written in HDF5 format using this modulemultiprocessing- Parallel processing is performed using this module (parallelization is under development)
Orion is an open-source package made available under the New BSD License.
Below is a list of useful articles that explains the multigrid-method used by Orion