The direct numerical prediction of broadband noise radiating from realistic turbulent flows interacting with solid surfaces is still in infancy. The main drawback is related to the computational efficiency - both in terms of processing time and storage capacity - but equally important is the accuracy of imposing turbulent inflow boundary conditions or the initiation of the solution with a realistic turbulent flow. In this paper, we introduce a divergence-free synthetic turbulent eddy model based on the assumption that turbulence can be considered as a superposition of random eddies convected with the mean flow. The vector potential and the requirement that the individual eddies must satisfy the linearized momentum equations about the mean flow are used to enforce the divergence-free condition. Experimental benchmark data for spatially decaying isotropic turbulence and nonhomogeneous rotor-wake turbulence are used to evaluate the proposed synthetic eddy method.
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