RESEARCH ON PARTICLE MOTION CHARACTERISTICS UNDER HYPERSONIC MARS ENTRY ENVIRONMENT

Dust storms of varying degrees frequently transpire within the Martian atmosphere, and the dust particles present in the atmosphere will cause erosion on the surface of high-speed entering Mars vehicles, leading to increased wall heat flux. Consequently, the design of the vehicle's thermal protection system is confronted with a formidable challenge. In this paper, focusing on the two-phase flow problem in the hypersonic Mars entry environment, a non-equilibrium flow field and particle one-way coupling calculation method based on the Euler-Lagrange framework are established. Moreover, a Mars atmospheric particle distribution model with a modal radius of 0.35 μm is adopted to investigate the motion trajectories of particles with different sizes in the flow field. The effects of the high temperature phase change model on the particle motion and the impact energy distribution of particles with different particle sizes were obtained. The numerical simulation results show that particles are prone to melt or even vaporize during their moving in high-temperature flow fields, and it was confirmed that the high-temperature phase change model engenders a more pronounced effect on the trajectory of smaller particles due to their diminished dimensions. Conversely, particles with diameter above 3 μm exhibited a larger Stokes number, and their motion trajectory remained relatively unaffected by the surrounding flow field, and the radii of these particles remained relatively constant during motion. Particles with a diameter larger than 3 μm account for more than 95% of the impact fraction on the wall, which is the main source of wall impact. The results of the impact energy fraction indicate that particles with diameters between 3 and 10 μm are the main source of impact energy, accounting for approximately 80% of the total impact energy.