I am trying to predict the far-field noise for aerofoil numerically using LES simulation and compare the simulation results to experimental data. To cut the computational cost, the simulation span is less than the experimental aerofoil span. The far-filed noise is corrected to account for short simulation span compared to experimental span depending on coherence length in the span-wise direction.

I have found these equations for calculating the span-wise coherence length. Does anyone has used these equations before?