Plume Impingement Analysis On The LunarLion

Open Access
Yeh, Shiang-ting
Area of Honors:
Aerospace Engineering
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Deborah A Levin, Thesis Supervisor
  • Philip John Morris, Honors Advisor
  • Robert Graham Melton, Faculty Reader
  • Lunar Lion
  • plume impingement
  • DSMC
Currently, Penn State is combining its interdisciplinary expertise to compete in a global race to land and operate a robotic spacecraft on the Moon by 2015 as part of the Google Lunar X-Prize Competition. My research aims to analyze the contamination and possible damages of the plumes coming from the spacecraft’s exhaust which will reflect off the lunar surface, implementing plume impingement analysis for the landing of the Penn State Lunar Lion spacecraft. The direct simulation Monte Carlo (DSMC) method will be used to model selected thruster configurations anticipated for the Lunar Lion project. My goal for researching and writing this thesis is to quantify plume impingement and determine the conditions that would cause impingement to be an operational problem. The SMILE code was used to implement the DSMC method. Calculations for the exit conditions were made from the specifications of the MR-107 thruster on the assumptions that the expansion of the gases from the nozzle throat to the exit was isentropic. Chemical reactions were assumed to be negligible aft of the nozzle exit. The SMILE code ran the DSMC for different scenarios with these initial conditions. The results indicate that there will be impingement upon the spacecraft. Although the major concern lies in the amount of ammonia that strikes the spacecraft and this number is the least of the three species involved. It is recommended that either the thrusters be positioned lower to give the gas plumes more room or that sensitive sensors not be placed in the plume contaminated areas of the spacecraft and the manufacturing of spacecraft shell take this potential contamination into account.