1968 · 20 citations · 0 references
EngineeringAerospace EngineeringMechanical EngineeringAcousticsAerodynamicsTunnel EngineeringAeroacousticsExperimental AerodynamicsHypersonic AerodynamicsSupersonic AerodynamicsWind-tunnel TestingAerodynamic NoiseBoundary Layer NoiseBoundary Layer Transition EffectsBoundary-layer TransitionDisplacement ThicknessReynolds Number EffectsSupersonic Wind TunnelsTurbulent Boundary Layers
Abstract : Boundary-layer transition and aerodynamic noise measurements were made on sharp leading-edge two-dimensional models in supersonic wind tunnels (1 ft to 16 ft). These data showed, conclusively, a significant and continuous increase in transition Reynolds number and a significant decrease in radiated aerodynamic noise (generated by the tunnel wall turbulent boundary layer) with increasing tunnel size. Results obtained in the AEDC-VKF Tunnel A from a shroud configuration placed concentrically around a hollow cylinder transition model and a flat plate microphone model further demonstrated the strong adverse effects that radiated aerodynamic noise will have on transition. A correlation of transition Reynolds numbers based on transition data from nine wind tunnels (3 or = M or = 8) was developed. The correlation was dependent only on the tunnel wall, turbulent boundary layer, aerodynamic noise parameters (displacement thickness and skin friction), and the tunnel test section circumference.