[MarkelRF]

I am analyzing the non-reacting turbulent flow over a triangle-shaped cylinder similar to the one studied in the paper "Modeling of Volvo Bluff Flame Experiment and Comparison of Finite-Volume and Discontinuous-Galerkin Schemes" by means of the KSKL-SAS model.

I have monitored wall total pressure at the station x/l = -0.1, with the origin placed immediately behind the triangle and at the line y=0. This leads to having 2 monitors, one for the cylinder wall located at y>0 and another one for the cylinder wall located at y<0.

I have first to determine the spectral density function of the wall pressure fluctuations, which I have done by means of a FFT performed over 20 time data-sets of 256 time-values for each data-set. A total of 5120 = 256 x 20 time steps have been taken.

My problem arises when trying to calculate the transfer function which relates the approaching flow velocity (U_inf) and the vortex shedding frequency (f_v). I am supposed to calculate this transfer function from the analysis of the wall total pressure at these two locations, and I am completely lost on how to do it.

I would really appreciate any help or indication on how to proceed.