Flow in a Y-Intake at Supersonic Speeds

Numerical simulation of the flow in a twin intake via solution to unsteady viscous compressible equations using a stabilized finite-element method has been carried out for various sideslip angles and backpressure ratios. Various flow regimes that are possible in the entire parameter space are identified. They are classified on the basis of shock structure and their locations and the unsteadiness in the flow. Buzz instability is observed in the intake at low system mass rates for nonzero sideslip angles. The onset of buzz is identified by zero mass flow rate in the leeward duct. It is associated with asymmetric movement of the bow shocks upstream of the duct entry. The onset of buzz is accompanied with a loss in static and total pressure recovery and increase in flow distortion. The effect of initial condition is studied. The flow in a certain regime is sensitive to the time history of the backpressure. Hysteresis in the flow as well as in the onset of buzz are observed. The effect of bleed is studied. The...

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