摘要
The pressure fluctuations in turbulent shear flows were investigated with the theory of spectral analysis. An expression for pressure spectra was analytically derived in terms of velocity spectra based on a formal solution of Navier-Stokes equation and on quasi-normal assumption to express the third and fourth order velocity correlations in terms of double velocity correlation. Then, a turbulent model for computing the pressure fluctuation intensity with Reynolds stress and mean flow velocity gradients was established. The turbulent constants in the model were calculated from the assumptions about the general behaviour of velocity spectra in high Reynolds number flows. Comparison with direct simulation of turbulent boundary layer was made. It was found that the turbulent-turbulent, cross correlation, and turbulent-shear source terms for mean square value of pressure fluctuation are of the same magnitude.
The pressure fluctuations in turbulent shear flows were investigated with the theory of spectral analysis. An expression for pressure spectra was analytically derived in terms of velocity spectra based on a formal solution of Navier-Stokes equation and on quasi-normal assumption to express the third and fourth order velocity correlations in terms of double velocity correlation. Then, a turbulent model for computing the pressure fluctuation intensity with Reynolds stress and mean flow velocity gradients was established. The turbulent constants in the model were calculated from the assumptions about the general behaviour of velocity spectra in high Reynolds number flows. Comparison with direct simulation of turbulent boundary layer was made. It was found that the turbulent-turbulent, cross correlation, and turbulent-shear source terms for mean square value of pressure fluctuation are of the same magnitude.
