基于拓扑优化和形状优化的低噪声齿轮室罩盖设计

Design of a Low Noise Engine Gear Cover Based on Topology and Shape Optimization

为了降低发动机齿轮室罩盖的噪声辐射，进行了齿轮室罩盖的噪声频谱分析和模态分析，确定了齿轮室罩盖噪声主要频率区域，使用HyperWorks／Optistruct软件，采用拓扑优化和形状优化的方法，对第5阶移频和重量最小为目标进行了优化设计。优化后的齿轮室罩盖重量减轻了0．46kg，第5阶模态频率被移出了危险区域，其余各阶模态频率均得到了提高。声学模拟计算结果表明：在1600～1700Hz频率区域内，优化后的齿轮室辐射噪声得到明显降低。

The noise frequency analysis and modal analysis were used to determine the critical frequencies of an engine gear cover in order to reduce the radiated noise of the gear cover. By using the method of shape optimization and topology optimization, both the shift of 5th order frequency and the weight of the gear cover were optimized through the software Hyper Works/Optistruct. As result, the weight of the gear cover is reduced by 0.46 kg and the 5th order frequency is shifted out from the risk area, and modal frequencies of the other orders are raised. The results of acoustic simulation show that in the frequency range of 1 600 1 700 Hz, the noise radiated from the gear cover is dramatically reduced.