涡轮增压器双流道涡轮壳喉舌结构对静压和BPF噪声的影响

Influence of the throat structure of turbocharger double-volute turbine housing on static pressure and BPF noise

为降低涡轮增压器涡轮机叶片通过频率(blade passing frequency,BPF)噪声,设计4种喉舌距离方案,仿真和试验研究喉舌结构对涡轮进口静压分布及涡轮机BPF噪声的影响。结果表明:气流在涡轮壳2个流道内的流动状态存在较大差异,靠近涡轮轮背的流道内气流压力高于远离涡轮轮背流道;涡轮进口静压在周向和轴向分布不均匀,尤其涡轮壳流道几何角为300°~30°时;流道喉舌结构是导致周向静压在涡轮壳流道几何角为300°~30°时剧烈变化的关键;适当增加2个流道喉舌距离,可以改善涡轮进口周向静压不均匀性和涡轮机BPF噪声,但轴向静压不均匀性无改善;2个流道喉舌距离增加12.1 mm,涡轮壳流道几何角为300°~30°时,静压分布极限偏差由4.21%减小到3.35%,涡轮机BPF平均噪声由98.13 dB降低到90.14 dB,降低了12.8%,主观评价噪声明显改善。该研究可以为改进喉舌结构设计及降低涡轮机BPF噪声提供参考。

In order to reduce the noise of turbine blade passing frequency(BPF) of turbocharger,4 throatdistance schemes are designed,and the effects of turbine housing throat structure on the static pressure distribution of turbine inlet and turbine BPF noise are investigated by simulation and experiment.The results shows that the flow state in the two flow volutes is quite different,the pressure in the volute near the turbine wheel back is higher than the one far away from the turbine wheel back.The static pressure distribution at the turbine inlet is non-uniformity in circumferential and axial,especially when the geometric angle of turbine housing is between 300° and 30°.The flow volute throat structure is the key factor that leads to the drastic change of static pressure when the angle is between 300° and 30°.The non-uniformity of the circumferential static pressure at the turbine inlet and turbine BPF noise can be decreased by appropriately increasing the distance between two throats,but the axial non-uniformity is not improved.The distance between the throats is increased by 12.1 mm,the maximum deviation of static pressure distribution between 300° and 30° decreases from 4.21% to 3.35%.The average turbine BPF noise is reduced from 98.13 dB to 90.14 dB,decreasing 12.8%.The subjective evaluation of noise is significantly improved.This study can provide a reference for improving the structure design of the throat and reducing the BPF noise of the turbine.