Aeroakustische Optimierung eines Geblaeses

Abstract

This is the third part of basic numerical research work conducted by the Institute of Design Aerodynamics at DLR Braunschweig, in order of the company AEG Kleinmotoren GmbH, Oldenburg, Germany. The numerical investigations have been made to optimize the aeroacoustics of ducted radiator fans. To find improved geometries of ducted fans, a design method is developed consisting of a validated singularity method and an optimization code. In the case of periodic signals the singularity method is a lifting surface method for both, aerodynamics and acoustics. In the case of random signals the method is a semi-empirical code for acoustics only. By optimization studies based on periodic and stochastic acoustic signals different improved blade geometries were found. The twist and airfoil geometry were kept fix. The first improved blade geometry is characterized by a forward.