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Setup for the FLASH hydrodynamics code to simulate flow around objects embedded in stellar envelopes. Written by Morgan MacLeod (@morganemacleod) and Andrea Antoni (@andreaantoni).

Installation

This repository contains two folders:

• cewt: The common envelope wind tunnel setup. This folder should go inside source/Simulation/SimulationMain/.
• cewindgrav: A physics module dependency of the main setup. This folder should go inside source/physics/Gravity/GravityMain/.

Example FLASH setup line

./setup cewt -3d -auto -maxblocks=1000 -objdir=obj_cewt +pm4dev +uhd
    cd obj_cewt; make

Important flash.par parameters

Simulations are mostly characterized by (see publications below for definitions)

• sim_q: mass ratio between the embedded object and the mass enclosed by its orbit.
• sim_epsilon_grad: dimensionless density gradient (number of density scale heights within an accretion radius).
• sim_radius: ratio between geometrical and gravitational radii for the embedded object.
• sim_bctype: whether the surface of the object behaves as a reflective (sim_bctype=1) or sink (sim_bctype=2) boundary. The reflective boundary requires the unsplit solver (+uhd in the setup line).

Citation

If you use this setup please cite the following publications:

• MacLeod et al. 2015
• MacLeod et al. 2017
• Yarza et al. 2022