Speaker
Description
Planetary dust particles are a severe threat to different sensitive surfaces of landers and rovers. The success of future missions requires tools for modelling such environments. Technical challenges are linked to accurately model major factors influencing the contamination transport: reconstruction of the plume flow field, regolith erosion, electrostatics, and particle-surface interactions.
A DUSTFLOW simulation tool was developed under the ESA Technology Development Element (TDE) programme [1] to address the complex multiphysics conditions characteristic of the lunar environment. While primarily intended for lunar applications, the tool is also adaptable to other extraterrestrial environments, such as Mars. Its core functionality lies in predicting particulate contamination transport and surface deposition during landers' descent and ascent phases.
Additional applications include risk assessment for assets in proximity to the landing zone and analysis of internal contamination within habitats.
One of the most computationally challenging tasks is to simulate particle movement and interactions due to the enormous number of transported particles. The Apollo lander's number of moved particles can reach up to 1011, assuming an erosion rate of the regolith is at 50 kg/s and a specific size distribution [2]. Storage of such data, assuming 6 DOF (degrees-of-freedom), would require 104 TB, and the computational expense of such a simulation would also be a significant obstacle to obtaining valuable results. A combined Eulerian-Lagrangian simulation approach is applied to reduce the number of particles in the simulation. Larger particles are simulated as 6 DOF, and an advected scalar field is considered for lower diameters.
The presentation will cover the software design and selected contamination simulation results for the full-scale test cases.
References
[1] ‘Particle modelling inside fairings during pre-launch and launch - CCN’, CCN1 to ESA Contract 4000131165.
[2] J. E. Lane and P. T. Metzger, ‘Estimation of Apollo Lunar Dust Transport using Optical Extinction Measurements’, Acta Geophys., vol. 63, no. 2, pp. 568–599, Apr. 2015, doi: 10.1515/acgeo-2015-0005.
