Separation mitigation using pressure feedback technique for hypersonic shock wave boundary layer interaction

Abstract

Present studies are focused on the use of pressure feedback technique as a separation control technique for ramp induced flow separation at hypersonic speed. Numerical simulations portrayed that though pressure feedback technique can reduce the flow separation, further cooling of the feedback channel enhances its potential for separation control. Marginal cooling of channel walls to 175 K has reduced separation bubble size by 18.18% while strong cooling of those walls to 50 K reduced the separation by 30%. Such low enthalpy perfect gas simulations also showed the lower effectiveness of pressure feedback technique with increased ramp angle. Further, it has been noticed from the perfect and nonequilibrium gas flow simulations that the cooling of pressure feedback channel introduces differential separation size for the same wall-to-total temperature ratio cases. Integration of cooled pressure feedback channel with blunt leading edge configuration showed reduced separation size for any bluntness radius. Effectiveness of this integration is seen in lowering the values of inversion and equivalent radii. Thus, use of cooled pressure feedback technique in conjunction with leading edge bluntness is not only seen to have reduced the intensity of shock wave boundary layer interaction but also has enhanced the controllability of blunted leading edge without altering the entropy layer–boundary layer interaction.

A computational study of leading-edge wall cooling effect on shock wave–boundary layer interaction in forward-facing step

“…The four different configurations show a clear difference in the size of the separation bubbles. Since the fluid solver for the forward-facing step has proven that the cooling channel has a larger potential for reducing separation bubble size, 41 the cooled leading-edge arrangement has been used.…”

Shock/expansion fan interaction with real gas effects for Earth and Mars atmospheric conditions

“…For the present study, the supersonic inlet and supersonic outlet boundary conditions are used for inlet and outlet of flow computational geometry while the free‐slip boundary condition is considered for wall surfaces. The real gas solver is validated with different numerical and experimental findings as reported in the literature 30–33 . In addition, a well‐validated perfect gas 31,34,35 solver is also employed for the present investigation.…”

“…The real gas solver is validated with different numerical and experimental findings as reported in the literature. [30][31][32][33] In addition, a well-validated perfect gas 31,34,35 solver is also employed for the present investigation.…”