AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Influence of Back Electrostatic Field on the Collection Efficiency of an Electrostatic Lunar Dust Collector
NIMA AFSHAR-MOHAJER, Chang-Yu Wu, Nicoleta Sorloacia-Hickman, University of Florida
Abstract Number: 86 Working Group: Aerosol Physics
Abstract Dusty environment of the lunar surface and deposition of the charged particles were troublesome in previous NASA explorations. An electrostatic lunar dust collector (ELDC) was demonstrated earlier as a highly efficient way of protecting exposed surfaces from the falling lunar particles. However, the ELDC collection plates attract particles continuously, and a layer of deposited particles carrying the opposite charge builds up on the plates. In this study, the effects of back electrostatic field on the performance of an electrostatic lunar dust collector (ELDC) were investigated.
First, the relationships between ELDC dimensions, collection efficiency and electrical properties of lunar dust particles were derived to develop a comprehensive model for any size of the ELDC. Then, a Lagrangian-based discrete element method (DEM) was applied to track particle trajectories, and sensitivity analyses were conducted for the concentration of the incoming particles and the number of the pre-collected particles at 50 V and 100 V. The obtained results from tracking particle trajectories confirmed the formation of eddies in proximity of the collection plate. The continuous particles introduced into the ELDC reduced the collection efficiency, and ultimately led to a suspended regime. The maximum duration the ELDC can run without significant loss in collection efficiency was estimated to be 10 days for the studied ELDC size and applied voltage. Since the electrical power consumption of the ELDC was found to be negligible, increasing the applied voltage was found to be the best option to counter the back electrostatic growth.
Keywords: Lunar dust, Particle collection, Electrostatic field