Sensitivity Of Compressor Performance And Tipleakage Vortices To Inhomogeneous Casing Heatflux Distributions

Abstract

Compressor cooling is a promising method for increasing the efficiency of aero engines. This paper shows that the application of this method is not limited to the thermodynamic effect of extracting the net heat flow, but also extends to the heatflux distribution provided by the cooling. To demonstrate this, we conducted an extensive numerical study featuring a wide range of heating and cooling distributions applied to the casing of a compressor rotor in a singlestage model, which was taken from the last stage of an experimentally validated fourstage highspeed compressor model. The results show that the benefit – or detriment – of these variations may be significantly impacted by the heatflux distribution applied. We show that, while the net heat flux proves to be the dominant factor, the local distribution may account for up to 14% in the massflow variability and up to 21% of the variation in the adiabatic rotor efficiency. The results suggest an influence of the heatflux distribution on the tipleakage vortex.

Robust Numerical Operating-Map Prediction through Systematic Selection of Turbulence Models

“…This also results in a decrease in the isentropic efficiency η is . Experimental data from Mimic et al (2021) allow for evaluating the shifts in the operating points due to different turbulence modeling. Turbulence model-wise, the speed lines predicted by k-ω SST setups are clustered densely towards the high mass-flow rates and, thus, partially lie within the measurement uncertainty from near choked conditions to the point where the peak experimental total-pressure ratio is reached.…”

“…Deformation of the blades due to rotational forces is taken into account, leading to an accurate representation of bladecurvature and tip-clearance at 95% of the design speed. The geometry corresponds to the setup used by Mimic et al (2021).…”