Swirl

A grid solver for fluid dyanmic equations - includes the fifth order WENO-JS and modified Roe solver.

A test project to learn and document hydrodynamics code.

Features

• WENO-JS fifth order
• Roe solver with WENO-Z fifth order
• Written in JAX

Installation

Dependencies:

  jax
  python
  numpy
  matplotlib

It uses the "cpu" version of jax by default. To change that, edit the following code:

  $ swirl-solver.py
jax.config.update('jax_platform_name', "cpu")

#can change it to "gpu"

Running Tests

To run tests, run the following command

  python swirl-solver.py

At the top of swirl-solver.py

# For a Density wave solution:
# Set up the test
BC, u0, rd, xlims, Tfinal = setup_test(1)

# For a Riemann solution (Sod Shock Tube):
# Set up the test
BC, u0, rd, xlims, Tfinal = setup_test(2)

To change flux method, solver type or time integration method, edit the following code:

flux_type, slvr, integ = laxf, weno5, RK4

# flux_type: laxf || slvr: solverf, weno5, roe || integ: RK1, RK3, RK4

Plotting

To activate plotting, in swirl-solver.py:

plots = True

Solver Parameters

In swirl-solver.py:

Z =  # No. of grid points
Co =  # CFL number