Comparing Compressibility Effects in Turbulence at Various Mach Numbers
Compressibility effects in a high speed turbulent flow were examined experimentally within a novel pressure vessel equipment setup. The equipment was assembled, validated and utilized in a series of air and SF6 test cases. Using these two gases allowed Reynolds Number to be adjusted separately from Mach Number. In this way, the boundary conditions and nature of the turbulence determined by Reynolds Number were maintained, however the compressibility effects determined by Mach Number were changed. The turbulent flows consisted of a solenoidal component generated by a high speed fan and a dilatational component by high sound pressure level (SPL) speakers. Large scale turbulence dynamics, including axial, radial and power profiles, remained similar for both gas cases. However, small scale turbulence dynamics, including velocity energy spectra and velocity derivative skewness, revealed compressibility effects at work for the high speed and high SPL cases in SF6.
Mach Number; Reynolds Number; Fluid Mechanics; Experimental; turbulence; compressible; energy spectra
Bewley, Gregory Paul
Cowen, Edwin Alfred, III
M.S., Mechanical Engineering
Master of Science
dissertation or thesis