Experimental Investigations of the NASA Common Research Semispan Model in the NRC 5-Foot Trisonic Wind Tunnel

摘要

An experimental aerodynamic investigation of the 2.7 percent scale NASA Common Research Model (CRM) in a semispan configuration was conducted in the National Research Council, Canada (NRC) 5-Ft. Trisonic Wind Tunnel. Data were obtained at a chord Reynolds number of 5 million for five model configurations. Model forces and moments, wing surface pressures and wing bending and twist were obtained in the current investigation. No semispan support corrections were made to the data published in this paper. Comparison of the data acquired in the semispan investigation are made with the published wall interference corrected data from the NASA fullspan tests conducted at both the NASA National Transonic Facility and 11-Ft. Transonic Wind Tunnel Facility. Comparison of the force and moment data in an absolute sense is made for the Wing-Body (WB) configuration while most of the remaining configurations are compared with the fullspan data in an incremental sense using the WB configuration as the baseline. For the WB configuration, the angle of attack and pitching moment coefficient as a function of lift coefficient were found to be within 0.1° and 0.01 of the fullspan data, respectively. However, the measured semispan drag coefficient was significantly higher compared with the fullspan data. The incremental effects of the nacelle/pylon to the WB on all force and moment coefficients were found to be consistent with the fullspan tests within the estimated experimental uncertainty. The incremental and absolute pitching moment effects of the horizontal stabilizer in the semispan test were found to be significantly different compared to the fullspan experiments. However, assessment of the biases or limitations of the semispan support interference on the aerodynamic characteristics of a fuselage mounted horizontal tail plane are not yet clearly understood as the reference fullspan data contain the blade sting support interference.