Anthony L Laganelli; John R Howe; Air Force Flight Dynamics Laboratory (U.S.); General Electric Company. Re-entry and Environmental Systems Division.
ADB023441 (from http://www.dtic.mil).
Research supported by the Air Force Flight Dynamics Laboratory, Air Force Wright Aeronautical Laboratories, Air Force Systems Command, United States Air Force, and performed by General Electric Company, Re-entry and Environmental Systems Division.
|描述：||xvii, 224 pages : illustrations ; 28 cm.|
|丛书名：||Technical report (Air Force Flight Dynamics Laboratory (U.S.)), AFFDL TR 77-59.|
|责任：||Anthony L. Laganelli, John R. Howe.|
An experimental program was conducted at the AEDC vonKarman facility, Tunnels A and B, in which acoustic pressure fluctuation data were acquired on a 7 degree half-cone-angle model featuring a control surface. The objective was to define the aeroacoustic environment applicable to re-entry vibration response analysis for both ballistic and maneuvering vehicles. Wind tunnel measurements were obtained at Mach 4 and 8 for several values of freestream Reynolds number and model angle of attack. Stationary zones of laminar, transitional, and turbulent flow over the model were achieved. Acoustic data were reduced to rms fluctuating pressure, and power and cross-power spectral densities. Results were normalized using local boundary layer parameters for comparison with previous high speed measurements. The present study re-examined the aeroacoustic environment prediction capability relative to compressible flow conditions. Moreover, boundary layer characteristic lengths and velocities were reviewed in order to develop normalization procedures required for development of appropriate aeroacoustic scaling laws. It was determined that fluctuating pressure characteristics described by incompressible theory as well as empirical correlations could be modified to a compressible state through a transformation function. In this manner, compressible data were transformed to the incompressible plane where direct use of more tractable prediction techniques are available for engineering design analyses.