Lattice boltzmann solver for 2D flow problems with an immersed particle (fsi through the external boundary force method, c.f. Wu and Aidun (2010), Simulating 3D deformable particle suspensions using lattice Boltzmann method with discrete external boundary force). The main.c file is an implementation for an ellipse in an oscillating Couette flow, which also computes the largest Lyapunov exponent for the particle orbit. More information about the methodology and implementation can be found here: https://www.diva-portal.org/smash/get/diva2:1078075/FULLTEXT01.pdf .