132 Megapixel image of simulated raindrop impact

132 Megapixel image of simulated raindrop impact

by Moritz Lehmann

This is a 132 Megapixel (16K) image of a simulated 7 mm diameter raindrop impacting the ocean at 9.55 m/s terminal velocity and 20° inclination, 1.5 milliseconds after impact. The physically accurate simulation with 169 million voxels was done with the FluidX3D software and took 6 minutes on an Nvidia Titan Xp GPU, including raytracing of the image.
The numerical method used is the lattice Boltzmann method (LBM) with a Volume-of-Fluid extension. To fit such a large grid into GPU memory, a custom in-place streaming scheme together with FP32/FP16S mixed precision compression is used: https://doi.org/10.48550/arXiv.2112.08926
Such simulated raindrop impacts have been used to study how microplastics may transfer from the ocean into the atmosphere: https://doi.org/10.1186/s43591-021-00018-8