基于流固耦合与多目标拓扑优化的低噪声塑料机油冷却器盖优化设计

机油冷却器盖属于薄壁件，距离振动激励源较近，容易产生较大的振动噪声，且内腔冷却液的存在对机油冷却器盖的振动噪声有着很大的影响。为有效的对塑料机油冷却器盖的振动噪声进行仿真研究及优化，将流体冲击压力作为预应力的同时，结合塑料机油冷却器盖与内腔流体的流固耦合模型，采用流固耦合的方法对塑料机油冷却器盖的振动噪声水平进行了预测评估；根据预测结果，识别出对噪声贡献度较大的耦合模态频率；以降低塑料机油冷却器盖整体噪声为总目标，以提高各贡献度较大的耦合模态频率为子目标，利用加权指数法建立了多目标优化函数，对塑料机油冷却器盖结构进行了多目标拓扑优化。结果表明，优化后降噪效果明显，总声功率级降低了1.79 dB。

Low noise optimization design of plastic oil cooler cover based on the liquid-solid coupling method and multi-objective topological optimization

It has been proved that oil cooler cover is a main source of surface radiated noise for engine. And the existence of cooling liquid has a great influence on the vibration of oil cooler cover. Taking the fluid pressure as pre-stress and using the liquid-solid coupling method, a liquid-solid coupled model is established and used to predict the vibration and radiated noise of plastic oil cooler cover firstly. According to the prediction results, the main coupling modal frequencies that have great contribution to the radiated noise of the plastic oil cooler cover are identified. Then the multi-objective optimization is applied to structure topography optimization using the exponential weighted method. Compared with the initial plastic oil cooler cover, it has a higher performance: the overall noise is reduced 1.79 dB.