Abstract
Environmental and amenity are keywords in recent design of automobile. In this situation improvement of performance of automobile air-conditioner is one of the important topics. This can be realized by optimization of design of each element composing the air-conditioner. Centrifugal fan (e.g., multiblade fan) is one of the basic elements of it. Noise reduction, improvement of efficiency, and down-sizing are important factors required for the improvement of the centrifugal fan being used to the air-conditioner. Experimental technique developed recently, e.g. PIV, provides us useful data for new design concept of the centrifugal fan. For example, PIV measurements of the blade passage flow in the impeller of the fan give practical knowledge for the blade shape design and for the noise analysis.