气动-声学风洞热交换器的气动噪声

Aero-noise of Heat Exchanger in Aero-acoustic Wind Tunnel

为了评估矩形翅片椭圆管热交换器的声学性能,用传声器在模型风洞中分别测量5个风速下热交换器进出口声学特性.通过试验发现,在所测量风速下,热交换器自身产生的气动噪声大小约为8.9～10.7dB,其能量主要集中在中低频.相同管排数下漩涡脱落频率随迎面风速呈线性增加,表明对于给定热交换器存在1个不变的斯托拉哈尔数.

In order to estimate the acoustic performance of the heat exchanger, microphones are used to test the acoustic performance of the heat exchanger inlet and outlet at a model wind tunnel. The test results show that the difference of total sound pressure level between heat exchanger inlet and outlet is almost 8. 9 - 10. 7 dB at five test velocities, and the frequency of aero-noise generated by heat exchanger is mainly in the low and middle frequency range. Further discussion shows that with the increasing in the upstream flow velocity, the frequency of shedding vortex increases linearly, suggesting the existence of a constant Strouhal number for a given heat exchanger.