抄録
It is cleared in relating to interaction noise from cross flow fan with experiments and numerical simulation that the tongue shape affects the characteristic of sound source. Interaction noise becomes remarkable large at the operating point. There are three parts of sound sources on the tongue of the interaction noise. The first one is located at the end edge, the second one is located at the middle of the tongue and the third one in the round corner when the flow from impeller reaches to the tongue. The large interaction noise isn't generated at the round corner of the tongue where the very large pressure fluctuation is emerged. But the middle part of the tongue is the main source of interaction noise. It is proposed that the tongue shape is shortened at middle part of the tongue and the interaction noise is reduced with it.
