Turbulent pressure statistics in the atmospheric boundary layer from large-eddy simulation

Turbulent pressure fluctuations advected past a sensor contribute to wind noise and can thus significantly degrade acoustic signals. In this study, large-eddy simulation is used to calculate the turbulent pressure field in three types of atmospheric boundary layers. A Poisson equation is used to represent turbulent pressure as the sum of mean-shear, turbulence-turbulence, subfilter-scale, Coriolis, and buoyancy parts. At variance-containing scales in the free-convection case, turbulent-turbulent pressure dominates over the entire boundary layer. It dominates also up to midlayer in the forced-convection case; above that mean-shear pressure dominates. In the stable case mean-shear pressure dominates over the entire layer. Part of the inertial subrange of the pressure spectrum is resolved in the forced- and free-convection cases; it is dominated by the turbulence-turbulence pressure and has a three-dimensional spectral constant of 4.0. This agrees well with quasi-Gaussian predictions but is a factor of 2 less than results from direct numerical simulations at moderate Reynolds numbers. Although past measurements of turbulent pressure have been hampered by instrumental problems, such measurements that could be used to determine the inertial subrange pressure spectral constant would be most useful.