SBLI in supersonic flow over a compression ramp
Supersonic air-breathing propulsion is characterized by high speed flow, aerodynamic heating, high heat fluxes into the structure, and strong shocks interacting with laminar or turbulent boundary layer leading to shock-boundary layer interactions (SBLI).
The compression ramp forms the basis of intakes in hypersonic air breathing flight vehicles . The supersonic free stream flow is de-accelerated and compressed before it enters the scramjet for combustion. The change in slope at the leading edge of the compression ramp gives rise to flow separation. Shock-boundary layer interactions (SBLI) gives rise to separation and reattachment shock and compression fan.
Shadowgraph of M = 2.9 supersonic turbulent flow over a 25 deg rigid compression ramp. RANS simulation using SST turbulence model.
Static fluid-structure interaction (FSI) simulation. 𝐸/𝜌∞𝑈2 ∞ = 3.18 × 103. Shadowgraph of M = 2.9 supersonic turbulent flow over a 25 deg flexible compression ramp. RANS simulation using SST turbulence model. Flexible ramp is modeled as a hyperelastic solid with a plane strain nonlinear strain-displacement relation.
Mid-point deflection. Dynamic FSI. M = 2.9 turbulent flow over a 25 deg flexible compression ramp. RANS simulation using SST turbulence model. Flexible ramp is modeled as a hyperelastic solid with a plane strain nonlinear strain-displacement relation. There is no flutter instability.
Streamlines over pressure contours
Shadowgraph
Sangeet Sourav Sunderroy, Tumkur Pradeepa Karnick and Kartik Venkatraman (2022). Shock boundary layer interactions in a supersonic flow over a flexible compression ramp in 2022 AIAA Aviation Forum, Chicago, IL, June 27-July 1, 2022. https://doi.org/10.2514/6.2022-4049.
Flutter instability sets-in when the flexible ramp is most flexible using a linear elastic plane stress element at Mach 2.9 and 25 deg wedge angle.
Numerical schlieren of supersonic flow over a flexible 25 deg flexible compression ramp when fluttter instability sets-in.
Sangeet Sourav Sunderroy, Magan Singh, Pradeepa Tumkur Karnick and Kartik Venkatraman (2023). Flutter instability in supersonic flow over a flexible compression ramp. In: 57th 3AF International Conference (AERO2023), Bordeaux, France, March 29-31, 2023.