Wind Tunnel Support System Influence on NASA Common Research Model at Low Speed Conditions

Abstract

Computational studies were conducted in order to gain an understanding and to quantify the impact of the model support system and aeroelastic wing deformation on the Common Research Model at subsonic inflow conditions at Re∞ = 11.6 • 10 6. Comparisons between results obtained in the European Transonic Windtunnel and from simulations using TAU reveal the extent of the modeling error introduced by neglecting the support structure. RANS simulations with and without the support system show that it has a near-field effect on the model's rear fuselage, significantly altering the pressure field and thereby impacting the force coefficients, most significantly drag and pitching moment. Aeroelastic wing deformation was also included in the investigation, showing non-negligible impact on the forces. The inclusion of the support system and wing deformation, as well as the use of advanced turbulence models, were shown to promise considerable error reduction potential in comparative studies between wind tunnel and simulation data.

Upstream wind tunnel model mounting: The forgotten method for road vehicle aerodynamics

“…), with significant alteration to local pressure distributions. [38][39][40] Rear-mounted ground vehicles can also be adversely affected in this way within the sensitive base wake, making true and accurate reproduction of the natural flow-field difficult to achieve. Mercker and Knape 41 identified this effect on a passenger car model, with a rearward-mounted sting entering at an angle through the back window shown to reduce drag by up to 4%.…”