Steady-state aerodynamics tip gap influence in atransonic linear cascade at near stall

A comparison of steady-state aerodynamics for two tip gap configurations in the KTH transonic linear cascade is presented. The experimental campaign is performed for 1% and 2% tip clearances. The operational point is representative of an open-source virtual compressor (VINK) operating near stall at part speed. The inlet Mach number (Mach 0:81) is above its airfoil critical value with a high incidence angle, producing a leading edge separation bubble. The measurement plane is at 85% span for each tip gap configuration. Steady-state aerodynamic measurements are presented at the passage and downstream the blades. The blade loading at the passages of interest is mapped by a set of instrumented blades containing 15 pressure taps. The downstream conditions are reconstructed by five-hole probe measurements. Numerical results are computed by the commercial software ANSYS CFX. A comparison of experimental and numerical data is presented to identify correlations and limitations. The scope of this paper is to experimentally and numerically determine the influence of tip gap variation in the steady-state aerodynamics in a transonic linear cascade where leading edge separation occurs.