Characteristics and Mechanism of Fluctuating Pressure on Turbulent Wall Surface in Planar Channel Flow
The objective of this investigation is to study the characteristics of the fluctuating wall pressure and the con-tribution of the velocity-field source terms in the boundary layer to the fluctuating wall pressure in a planar channel flow.Based on the DNS results of the channel flow in the Johns Hopkins turbulence databases,the Green's function was used to solve the Poisson equation to build the theoretical relationship between the velocity-field source terms in the boundary layer and the fluctuating wall pressure.The fluctuating wall pressure and the partial pressure spectrum were calculated by Fourier transform to reveal the characteristics of the fluctuating wall pressure in wavenumber-frequency domain and analyze the rela-tive contribution of different source terms in different regions of the boundary layer to the fluctuating wall pressure.Results show that the auto-power spectrum of the fluctuating wall pressure has the shape of ω2 at low frequencies,ω-0.775 at medium frequencies andω-5 at high frequencies.In the wavenumber-frequency spectrum of fluctuating wall pressure,there is a con-vection ridge with a high spectral level at the wavenumber of 130 rad/m and the frequency of 120 rad/s,which reveals that the convection velocity of turbulent vortex structure is about 0.54 times of the flow velocity.The wall fluctuating pressure is mainly affected by the mean shear turbulence term Pms and turbulence-turbulence term Ptt in the velocity-field source terms,and the contribution of the mean shear term is the dominant.
vibration and wavechannel flowfluctuating wall pressurecharacteristicsmechanismboundary layer
万方数据
维普
