Perspectives on OpenFOAM numerical simulations of slope winds in Mars

Abstract

Planetary boundary layer phenomena, such as slope winds and nocturnal low-level jets, are frequent on Mars, e.g., whenever diurnal surface temperature variations are significant, and large-scale winds are weak. In particular, thermally-driven winds are very common over sloping regions; they can reach significantly high speeds for steep slopes, and govern near-surface winds in many sites. Simulations of this type of flows on Earth have usually been conducted using commercial computational fluid dynamics software (CFD). In this work, a set-up is described for numerically simulating slope flows on Mars within the framework of the open-source code OpenFOAM CFD. For this purpose, thermally-driven winds are analysed in an idealised 2D Martian mountain-valley system with realistic values of parameters such as the slope angle, temperature difference between the atmosphere and slope, etc. The fluid domain dimensions, and the temperature and pressure initial and boundary conditions used in this work were tested and proven suitable in previous similar investigations for Earth applications. Large-eddy simulations (LES) turbulent model is used here. The results obtained for velocity and temperature profiles are shown both for anabatic (up-slope) and katabatic (down-slope) winds. This study shows the potential of the proposed methodology and the performance of OpenFOAM. Future work aims at facilitating the screening of large numbers of candidate landing sites for future Mars missions, and at estimating the thermally-driven wind speeds for wind resource assessment.This work has been supported by the project PID2019-105162RB-I00 funded by MCIN/AEI/10.13039/501100011033 and by the project 2017 SGR 1278 from the AGAUR from Generalitat de CatalunyaPeer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.2 - Per a 2030, augmentar substancialment el percentatge d’energia renovable en el con­junt de fonts d’energiaObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.1 - Per a 2030, garantir l’accés universal a serveis d’energia assequibles, confiables i modernsPostprint (published version