Influencing factors on acoustical simulations including manufacturing tolerances and numerical strategies

This paper deals with some significant aspects of numerical sound calculation and measurement of electrical machines, using a claw-pole alternator as illustration. An acoustical simulation method is used to calculate the effects of manufacturing tolerances, which primarily influence the air gap geometry. To compare the acoustical measurements with calculations, important aspects of force transformation within models of very different mesh densities and variations of mechanical material properties are investigated in this paper.