Reynolds Number Effects on the Surface Pressures on a 5.2%-Scale High Lift Common Research Model

A 5.2%-scale High Lift Common Research Model (CRM-HL) semispan wind tunnel model was tested at the National Transonic Facility (NTF) wind tunnel in Hampton, VA. One of the primary objectives of the NTF test was to determine the effect of varying Reynolds number on the configuration. Using a combination of air and cryogenic nitrogen during testing, Reynolds numbers, based on the mean aerodynamic chord of the model, from 1.6 to 30 million were obtained. The focus of this work was on the landing configuration, which was tested at a speed of Mach 0.2. Surface pressure data were obtained at 10 chord stations on the wing, using static pressure taps distributed across the slat, main element, and flap. Comparisons of the surface pressure data at an angle of attack in the linear range of the lift curve (8 degrees) and at the maximum lift coefficient (����,������) were studied and compared at each Reynolds number tested. Trends in the surface pressures were also examined with respect to measured lift and pitching moment data to determine the most likely aerodynamic contributors. Overall, the surface pressure results for the landing configuration corroborated lift coefficient changes seen with different Reynolds numbers in both the linear and ����,������ regions of the lift curves.