Investigation of Supersonic Retro Propulsion Flow Fields for Central Jets and Peripheral Jets on Re-Entry Bodies

NASA's Entry, Descent, and Landing (EDL) space technology is introduced new techniques to achieve human exploration of Mars in the coming decades. One of those technologies, termed Supersonic Retropropulsion (SRP), involves initiation of propulsive deceleration at supersonic Mach numbers. The potential benefits afforded by SRP to improve payload mass and landing precision make the technology attractive for future EDL missions. NASA's EDL project spent two years advancing the technological maturity of SRP for Mars exploration. To model the flow field that exists for a vehicle employing SRP, multiple simulation method has been examined. Wind tunnel testing on scale model allows for visualization of the actual flow field structures using schlieren or shadowgraph images. Pressure ports on the body allow for data to be taken to characterize the effects of configuration and thrust level on the aerodynamics of the vehicle. In addition to characterizing the SRP environment, this datasets provide a validation database against with other modeling techniques can be compared. CFD approaches numerically solve the underlying flow equations to generate the solution of the expected flow structure and vehicle aerodynamics. This paper deals with the investigation on the effects of retro propulsion on the blunt body reentry vehicle in an opposing supersonic free stream. The focus is on aerodynamic properties for the application of EDL design and computational simulation development .This paper does not discuss non propulsive supersonic decelerators, detailed aero thermodynamic issues, slender body geometries or exhaust plumes in direction other than the free stream direction. This it also compare the results obtained in central peripheral nozzle locations as well as the computational simulation of supersonic retro propulsion flow fields and limitations of this work.