Aero-Acoustic Design of Fan Using Inverse Method
A multi-dimensional inverse algorithm was developed to design low noise fan. In this approach, mean-line analysis, 3-D CAD, automatic grid generation method, and CFD solver can be integrated with aero-acoustic inverse design method. The overall sound pressure level distributions obtained from specified sets of unsteady blade loading distribution serve input data to the multi-dimensional acoustic inverse module, and may be used to design optimal geometry to satisfy the aerodynamic and aero-acoustic performance. To execute an effective inversion of non-minimum phase system, SVD is introduced. With the inverse design concept used in the developed software, the design phase of an optimal blade geometry, which yields a required aerodynamic performance with minimal acoustic noise, may be significantly shortened. The experimental result of prototype fans, designed by using this software, showed that the aerodynamic and aero-acoustic performance is reasonably well predicted.