飞轮壳结构刚度对机体NVH性能的影响

以某柴油机为例,研究飞轮壳结构刚度对柴油机机体振动问题的影响.建立发动机整机多体动力学计算模型,并对发动机虚拟样机模型进行试验验证；引入拓扑优化计算方法,以飞轮壳结构刚度最大为优化目标,飞轮壳体积比为约束条件,单元密度为设计变量对飞轮壳结构进行优化设计；并结合工程设计经验对优化后的飞轮壳模型重新建模.分析在安装新飞轮壳之后发动机机体振动和声学特性,计算结果表明,在对飞轮壳结构进行优化设计之后,机体振动问题得到了有效的缓解,辐射声功率级降低了0.3 dBA,提高飞轮壳结构刚度能够有效降低机体振动,改善机体振动、声学性能.

Influence of flywheel cover structural stiffness on engine body NVH performance

Used one diesel engine as an example, the affect of fly wheel cover structure stiffness to diesel engine vibration performance was studied. First, the engine computational model was established, and validated by experiments. Then, the topology optimization for flywheel cover was carried out, taking the structural stiffness for optimization objective, the volume ratio for constraints, and element density for variable. Combined engineering experience, the optimized model was rebuilt. Finally, the new engine computational model was established, and the vibration and acoustic performance of the new engine was simulated. The simulation results showed that, the vibration of the engine body was obviously decreased, and the radiated sound power level was reduced 0.3 dBA. The optimization for the flywheel cover could effectively improve the vibration and the acoustic performance of the engine body.