Numerical investigation of the influence of the “ExoMars” spacecraft propulsion system jets on erosion of the Mars surface

The paper presents results of mathematical modeling of the effect caused by supersonic propulsion system jets on the surface of Mars during the descent of the ExoMars module. The action of propulsion system supersonic jets on the Mars surface was investigated numerically using the OpenFOAM software. According to results of the force action of supersonic jets on the Mars surface, the possible erosion of the Mars soil is estimated using Coulomb's law of shearing resistance. The soil model involves empirical constants which were obtained from previous Viking, Pathfinder, and MER space programs. The soil erosion during the landing of the spacecraft on the surface of Mars under the influence of the propulsion system at the maximum and minimum mode for loose, lumpy soil, and sand was investigated. During the numerical research, the distance from which soil erosion begins was revealed. The destructive force of propulsion system supersonic jets is greatest at one meter height and below. At the time of the spacecraft contacts with the surface of Mars at the maximum mode of the propulsion system, erosion of all soil types is possible except for the loose soil; for the minimum mode of the propulsion system, erosion is not observed.