南水北调天津干线湖沼相软粘土物理力学特性探讨

通过对南水北调中线一期工程天津干线软粘土的分布、成因、物理性质的综合分析,提出了临时基坑边坡开挖建议参数.     

Turbocharger Noise Prediction Using Broadband Noise Source Model

The noise prediction of the turbocharger is studied. The broadband noise source model is employed to predict the near-field noise of the turbocharger. The 3D software Solidworks is adopted to establish the model blades and inlet of turbocharger compressor, then this 3D model is introduced into the software CFD to calculate the flow-field under different inlet shapes, different blades shapes and different clearances between casing and impeller. On the base of the above simulation, the broadband noise source model is employed to calculate and analyze the near-field noise. The calculation shows that compressor static pressure values and the sound power values near the impeller outlet are the largest. Through the noise calculation by using broadband noise source model under different inlet shapes and blade shapes, we find that the noise level of the inlet of cylindrical and cone types are smaller. Compared with the current widespread used backward skewed or radial blades, there is little difference of the noise value of the inlet of the forward skewed blades.