Publication Date:
2019-07-13
Description:
Computations are performed to study the boundary layer instability mechanisms pertaining to hypersonic flow over blunt capsules. For capsules with ablative heat shields, transition may be influenced both by out-gassing associated with surface pyrolysis and the resulting modification of surface geometry including the formation of micro-roughness. To isolate the effects of out-gassing, this paper examines the stability of canonical boundary layer flows over a smooth surface in the presence of gas injection into the boundary layer. For a slender cone, the effects of out-gassing on the predominantly second mode instability are found to be stabilizing. In contrast, for a blunt capsule flow dominated by first mode instability, out-gassing is shown to be destabilizing. Analogous destabilizing effects of outgassing are also noted for both stationary and traveling modes of crossflow instability over a blunt sphere-cone configuration at angle of attack.
Keywords:
Aerodynamics
Type:
AIAA Paper 2011-3303
,
NF1676L-11713
,
41st AIAA Fluid Dynamics Conference and Exhibit; Jun 27, 2011 - Jun 30, 2011; Honolulu, HI; United States
Format:
application/pdf
