Numerical study of three dimensional acoustic resonances in open cavities at high Reynolds numbers

Abstract

We present two and three dimensional numerical simulations over open cavities at high Reynolds (Re=8.6×105) and various Mach numbers (0.2<M<0.8). Various turbulence closures are compared and the effect of the Mach number and three-dimensionality assessed. Results show that an implicit LES approach provides more accurate results that classic RANS models (e.g. k–epsilon variants) when analyzing the spectra associated to Rossiter's acoustic resonances (regular self-sustained oscillations). In addition, we show that the simulations require relatively high Mach numbers to compare favorably to experimental data, showing the importance of compressibility effects. Finally, to capture qualitatively the dynamical content, we show that 2D simulations are not accurate enough and three dimensional simulations are necessary.