NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA DISSERTATION OPTIMAL CONTROL OF SHOCK WAVE ATTENUATION IN SINGLE- AND TWO-PHASE FLOW WITH APPLICATION TO IGNITION OVERPRESSURE IN LAUNCH VEHICLES by Nathan D. Moshman December 2011 Dissertation Supervisor: Sivaguru S. Sritharan Committee Chair/Co-Supervisor: Garth V. Hobson Approved for public release; distribution is unlimited