The Effects of Mach Number Control Precision on Airfoil Pressure Measurement in a Transonic Wind Tunnel

摘要

Mach number is one of the most important similarity parameters in wind tunnel experiments, and the control precision on it directly influences the credibility and accuracy of test data. This paper, based on the analysis of Mach number control method, puts forward a measure which may probably improve the control precision on Mach number. By designing and conducting airfoil pressure measurement test, the feasibility of the measure was verified. The results show that, the control precision of Mach number can be improved by raising the control precision of total and static pressures of wind tunnel tests. With the measure, the maximum Mach number fluctuation is reduced from ±0.003 to ±0.001, correspondingly the measured pressure distribution is more accurate, the lift and drag curves are more reasonable in post-stall region.