发动机进气歧管的气动噪声预测方法研究
Prediction Method Research of Aerodynamic Noise for Engine Intake Manifold

为更加准确预测发动机进气噪声，发展了采用瞬态边界计算进气歧管流场的方法，并联合声学软件进行声场预测。从一维仿真模型获得可靠的压力和速度边界用于流场计算；采用大涡模拟（LES）和分离涡模拟（DES）两种求解算法模拟歧管内的流场；通过声学有限元方法计算进气口辐射的气动噪声。LES和DES两种方法的流场结果对比表明，DES结果与LES非常接近，同时耗时更少；声场结果与实验结果吻合较好，证明了本文预测方法的准确性；模拟结果和压力边界频谱图的对比分析使空滤器和进气歧管设计更具针对性。
In order to predict the engine intake noise accurately, transient analysis is used in aero-acoustics calculations of intake manifold flow, and the acoustics field distribution is simulated in acoustics software. Establish a one-dimensional engine model which is calibrated by experimental data to output reliable pressure and velocity results for flow field calculation. Two turbulence models, the large eddy simulation (LES) and detached eddy simulation (DES) methods are used separately to simulate the flow field in the manifold accurately. The aerodynamics noise is calculated by acoustic FEM method using surface pressure distribution. Comparisons between two algorithms indicate that DES can get results of similar accuracy with LES while DES using less time. The results are compared with NVH test data and the accuracy of simulation method is verified. The spectrum analysis between simulation results and pressure boundary in frequency domain make the design of vacuum filter and intake manifold more specific