This exceedingly simple two dimensional simulation of a rising bubble took 15 hours and 350 processors on a supercomputer, representing 4 seconds of physical time.
Why did it cost so much?
ANSWER: The resolution of this simulation is approximately 1 mm which corresponds to 500 points covering the bubble (Diameter = 0.5m). Additionally the Reynolds Number (Re), which quantifies relationship between inertial and viscous forces, is very low (35 and 3.5 in liquid and gas respectively), requiring in a time-step of 0.5 microseconds. This results in a configuration dominated by diffusion and is designed to test limitations of our open-source software, Flash-X, which uses a fully explicit method for solving Multiphase Navier-Stokes equations.
@software{akash_dhruv_2023_10215417,
author = {Akash Dhruv},
title = {{Lab-Notebooks/Outflow-Forcing-Revised: zenodo
archive}},
month = nov,
year = 2023,
publisher = {Zenodo},
version = {zenodo},
doi = {10.5281/zenodo.10215417},
url = {https://doi.org/10.5281/zenodo.10215417}
}