Anisotropic filter for synthetic turbulence
Zhen Shen
Last updated on March 24, 2020
To develop a new method of synthetic anisotropic turbulence by deriving a general form of anisotropic filter that generates the homogeneous anisotropic turbulence. To investigate the influence of anisotropy on turbulence-airfoil interaction noise by applying various stretching ratios.
The effectiveness of pseudo three-dimensional anisotropic filter is verified by comparing with Amiet’s analytical solution. The turbulent velocity field induced by the anisotropic filters can be regarded as the pseudo three-dimensional anisotropic turbulence, which will reproduce the major statistics of three-dimensional turbulence
Through an integral solution of the three-dimensional FW-H equation, the far-field SPL spectra is obtained, which shows good agreement with the theoretical solution, to within 1.5 dB accuracy. It can be concluded that doubling of the tangential turbulent length scale leads to 9 dB increase in SPL spectra, which is attributed to the octupling of one-dimensional energy in the transverse direction.
