AIAA Journal · 1975 · 103 citations · 12 references
EngineeringAerospace EngineeringAcousticsAerodynamicsTunnel EngineeringAeroacousticsBoundary-layer TheorySupersonic AerodynamicsTurbulenceTurbulent FlowWind-tunnel TestingAerodynamic Noise CharacterizationBoundary Layer NoiseBoundary Layer Noise ControlPower Spectra Of TurbulencePressure LoadsSupersonic Wind TunnelsTurbulent Boundary LayersTurbulent Transition
High noise levels in conventional supersonic and hypersonic wind tunnels prevent further advances in transition research. The study presents experimental data on noise‑reduction techniques in supersonic and hypersonic wind tunnels, including laminarization of nozzle wall boundary layers and noise‑radiation shields. The data show that tunnel noise dominates transition and turbulent pressure loads when rms pressure exceeds about 1 %, can alter the structure of turbulent boundary layers, and, together with observed Taylor‑Gortler vortices, set limits on the quiet performance of a proposed 20‑in tunnel.
High noise levels in conventional supersonic and hypersonic wind tunnels prevent further advances in transition research. Recent data confirm previous results that transition is dominated by tunnel noise when the rms pressure intensities exceed about 1%. High facility noise levels also dominate fluctuating pressure loads under fully turbulent boundary layers. Recent data on the power spectra of surface pressures indicate that the basic structure of turbulent boundary layers may be modified by high facility noise levels. Experimental data for current techniques to control and reduce noise levels in supersonic and hypersonic wind tunnels by laminarization of nozzle wall boundary layers and by noise radiation shields are presented. These results and possible effects of Taylor-Gortler vortices observed in a nozzle wall boundary layer are used to predict the limits of quiet performance for a proposed 20-in. quiet tunnel.
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