From Simple to Full Numerical Approaches to Compute Fan Noise

2.5 Noise Prediction by Analytical or Numerical Models

It is now possible to approach the estimation of the noise radiated by a fan in a full numerical way, thanks to the constant increase of computer capacities. However, these full numerical approaches stay difficult to carry out, due to the high computational resources and the high level of skill needed. Some simpler methods, based partially on experimental data and empirical models, still retain their interest, and are by far more affordable for industrial applications.
The CETIM's contribution to a common study involving three partners VKI, CETIAT and CETIM, is presented. The goal of this study is to compare different methods allowing to estimate the noise radiated by fan, from semi-empirical to full numerical approach. The pro and cons of the semi empirical approach based on a database of wing profile noise are reviewed, and compared to the results obtained by the others partners of the study, which involve stationary or transient CFD computation.