Performance Analysis of a Compressor Leading Edge without Pressure Spike at High Subsonic Speed

Abstract

This paper describes an experimental investigation on a state-ofthe-art compressor airfoil with three different leading edges at high subsonic flow conditions. In addition to a conventional circular and elliptical geometry which possess curvature discontinuities at the blend points, a continuous curvature leading edge is studied. The investigation considers the performance at design incidence, as well as the impact of off-design incidences. Pressure spikes near the leading edge can lead to early transition associated with higher profile losses. Goodhand and Miller [1] showed that in low subsonic conditions the avoidance of curvature discontinuities can diminish pressure spikes and therefore reduce the profile losses and enlarge the working range. In this paper, measurements are conducted to assess the potential of this concept for a high-pressure jet engine compressor airfoil operated at high subsonic conditions (M 1 = 0.7, Re d/2 = 20, 000). The results show that, at design incidence, the total pressure loss coefficient of the continuous curvature leading edge reduces by up to 15.4 % compared to the circular leading edge and by up to 3.1 % for the elliptical geometry. At off-design incidence, the reduction can be up to 40.2 % at maximum positive incidence under consideration.

Calibration of Spalart-Allmaras model for simulation of corner flow separation in linear compressor cascade

“…The linear compressor cascade recently tested in RWTH Aachen university (Lang et al, 2019) was used in this work to provide the experimental results for both calibration and validation of the calibrated turbulence model. To represent the compressor flow physics as closely as possible, the Reynolds number based on chord length of the experimental setup was set to 10 6 while the inlet Mach number was set to 0.7.…”

“…The experimental uncertainty of total pressure measurement was determined to be +150 Pa (corresponding to a +0:003 uncertainty in Mach number). For additional details regarding experimental setup and measurements, see (Lang et al, 2019).…”