Stress-blended eddy simulation of shock and film cooling for trailing edge cutback in supersonic flow

Abstract

This study employs stress-blended eddy simulation to examine shock interference and film cooling behavior in a supersonic crossflow. Coolant coverage and fluid dynamics are evaluated at two mass flow ratios (MFR) and four typical lip shapes. Numerical schlieren techniques effectively capture shock-expansion wave dynamics, providing the flow behavior visualization. The complete wave system includes the strong shock-separation shock on the pressure lip and symmetric lip-shocks accompanied by an expansion fan on the suction lip. Notably, the weak shock II is identified as a key factor influencing transient heat transfer and coolant mixing downstream of the cutback. Film cooling efficiency in supersonic crossflow is shown to depend strongly on coolant momentum. Quantitatively, the area-averaged cooling efficiency increased by a maximum of 28.5 % as the MFR increased. At lower MFR, variations in the recirculation zone and the interaction with Shock II reveal how lip geometry impacts cooling performance. Additionally, instantaneous film instability is analyzed to understand their impact on wall thermal integrity. Among the designs examined, the down-round lip design offers superior cooling performance at lower coolant. These findings provide new insights into supersonic cutback film cooling and contribute to advancements in managing compressible flow for improved thermal protection.