How to import an STL file and run a simulation with an immersed body

This tutorial is designed for an Ubuntu workstation for the simulation around a sphere.

Install the xcompact3d toolbox

First you need to make sure to have conda installed on your machine. See for instance here for an installation on Ubuntu. We only tried to install the xcompact3d toolbox with Python 3.10 and Python 3.12.

conda create -n x3d python=3.XX
conda activate x3d
pip install xcompact3d-toolbox

Install and compile Xcompact3d

git clone https://github.com/xcompact3d/Incompact3d.git
cd Incompact3d/
export FC=mpif90
cmake -S . -B build
cd build/
cmake --build . -j 8

The executable file is in the build/bin directory

Bug fix in the xcompact3d_toolbox package

open /home/username/anaconda3/envs/x3d/lib/python3.12/site-packages/xcompact3d_toolbox/sandbox.py and change all instances of longdouble to double (lines 438-441)

Generate the initial conditions including the epsilon function

cd examples/Sphere
python3 generate_initial_conditions.py

Run the simulation on 8 cores (~7minutes)

mpirun -np 8 ../../build/bin/xcompact3d