Pulsating Coolant Ejection Effects Downstream of a Supersonic Trailing Edge

Trailing edge blowing is used in a great variety of applications. In particular, high-pressure turbines bleed about 3% of the engine core massflow through a rear slot of the inlet guide vanes. At transonic conditions the coolant flow alters substantially the base region characteristics, and therefore the wake and shocks. Certain pulsating coolant frequencies give rise to exotic vortical shedding structures, not observed when the coolant is continuous. A detailed analysis of the flow field near the trailing edge region has been performed using the in-house HybFlow code. Blunt and circular trailing edges, exposed to continuous blowing (at different rates) were compared by using steady simulations. Both shock intensity and wake loss are discussed in this paper considering pulsating coolant ejection at various frequencies and blowing ratios