Supersonic wind tunnel

About: Supersonic wind tunnel is a research topic. Over the lifetime, 3942 publications have been published within this topic receiving 43834 citations.

Low-Speed Wind Tunnel Testing

Abstract: Wind Tunnels Wind Tunnel Design Pressure, Flow, and Shear Stress Measurements Flow Visualization Calibration of the Test Section Forces and Moments from Balance Measurements Use of Wind Tunnel Data: Scale Effects Boundary Corrections I: Basics and Two- Dimensional Cases Boundary Corrections II: Three-Dimensional Flow Boundary Corrections III: Additional Applications Additional Considerations for Aerodynamic Experiments Aircraft and Aircraft Components Ground Vehicles Marine Vehicles Wind Engineering Small Wind Tunnels Dynamic Tests Appendices Index

Strouhal numbers of rectangular cylinders

Abstract: Experiments on the vortex-shedding frequencies of various rectangular cylinders were conducted in a wind tunnel and in a water tank. The results show how Strouhal number varies with a width-to-height ratio of the cylinders in the range of Reynolds number between 70 and 2 × l04. There is found to exist a certain range of Reynolds number for the cylinders with the width-to-height ratios of 2 and 3 where flow pattern abruptly changes with a sudden discontinuity in Strouhal number. The changes in flow pattern corresponding to the discontinuity of Strouhal number have been confirmed by means of measurements of velocity distribution and flow visualization. These data are compared with those of other investigators. The experimental results have been found to show a good agreement with those of numerical calculations.

Linear Stability Theory and the Problem of Supersonic Boundary- Layer Transition

Abstract: Compressible linear stability theory is first reviewed and then used to calculate the amplitude ratio of constant-frequency disturbances as a function of Reynolds number for insulated and cooled-wall flat-plate boundary layers between Mach numbers 1.3 and 5.8. These results are used to examine the consequences of using a fixed disturbance amplitude of the most unstable frequency as a transition criterion. The effect of the freestream Mach number M1 on the transition of insulated-wall boundary layers is calculated using two different assumptions concerning the initial boundary-layer disturbance amplitude A0. It is found that the shape of the transition Reynolds number Ret vs MI curve observed in wind tunnels can be closely duplicated. As a second example, the effect of wall cooling at MI = 3.0 is calculated. A much faster increase of Re, with cooling is obtained than is observed experimentally. However, when A0 is determined from the forced response of the boundary layer to irradiated sound and from the measured freestream power spectrum, a rise in Re, similar to what is observed is obtained for a certain amplitude criterion.

Wind Tunnel Experiments Relating to Supersonic and Hypersonic Boundary-Layer Transition

Abstract: Hot-wire anemometry is used to study the origin and growth of "natural" fluctuations in zero pressure-gradient boundary layers for several Mach numbers between 1.6 and 8.5. The importance to transition of certain physical mechanisms is examined through comparison of the fluctuation growth with the sound-forcing and stability theories of Mack. Flow fluctuations of substantial amplitude were observed within the laminar layer ahead of stations where instability amplification is expected to be important. These fluctuations were found to be cross-correlated with the sound field for the higher supersonic speeds, but not for the lower ones. The fluctuation growth rates in the unstable Reynolds number range ahead of the nonlinearity region were in reasonably close agreement with the theory for Mach 4.5; the agreement for Mach 2.2 and 8.5 was qualitative. The second mode of instability was predominant at Mach 8.5.