压缩机壳体的低噪声优化技术研究

发布时间：2018-12-19 11:49

【摘要】：声辐射结构的拓扑优化问题是近年来结构优化领域的一个热点。目前的研究多集中于结构厚度分布的拓扑优化和固定位置筋板厚度、高度等参数的优化,且主要集中于具有解析解的结构,对于筋板布局的拓扑优化较少,鲜见对压缩机壳体这种非规则形状的加筋板的布局优化。本文着重研究基于快速边界元法求解拓扑声学灵敏度实现筋板最优分布的板壳拓扑优化方法。以减少结构辐射声为目标的优化设计,通过改变结构的形状、筋肋的位置和尺寸等,降低结构的辐射声功率,由于声功率计算需要对结构的振动速度分布函数作表面积分,优化设计的计算成本巨大。本文将快速多极子边界元法与拓扑声学灵敏度分析方法相结合,大大降低了优化过程的计算量,实现了筋板的最优分布。本文利用快速多极子边界元计算效率高的特点,以辐射声功率为目标函数,单元刚度为设计变量,通过全局有限差分法求解结构的拓扑声学灵敏度,基于灵敏度的分布获得需增加刚度的优化区域。并以一球壳为例分析了结构在简谐力作用下的声辐射拓扑优化,在分析声学灵敏度的基础上通过实现筋的最优布局,降低了结构的辐射声功率。本文根据压缩机噪声声功率测试分析结果,确定噪声的主要频率,以主要频率段的辐射声功率为目标函数,对冰箱压缩机壳体作拓扑优化设计,通过局部加筋,提高壳体刚度,减小壳体表面的法向振速,改变法向速度分布,降低壳体声辐射效率,成功实现了对压缩机壳体筋板布局分布的拓扑优化,并通过试验验证了数值仿真的结果,表明了本文方法的有效性。结果表明,基于快速边界元法求解拓扑声学灵敏度提高了拓扑声学灵敏度的求解效率,实现了结构筋板的最优布局设计,从而有效降低结构的辐射声功率,适用于工程实际应用。
[Abstract]:The topology optimization of acoustic radiation structures is a hot topic in the field of structural optimization in recent years. The current research focuses on the topology optimization of the thickness distribution of the structure and the optimization of the thickness and height of the stiffened plate at fixed position, and mainly focuses on the structure with analytical solution, but the topology optimization of the stiffened plate layout is less. It is rare to optimize the layout of stiffened plate with irregular shape of compressor shell. This paper focuses on the optimization method of plate and shell topology based on the fast boundary element method to solve the topological acoustics sensitivity of stiffened plates. By changing the shape of the structure, the position and the size of the rib, the radiated sound power of the structure can be reduced. Due to the calculation of the sound power, the vibration velocity distribution function of the structure needs to be integrated on the surface. The calculation cost of optimization design is enormous. In this paper, the fast multipole boundary element method is combined with the topological acoustic sensitivity analysis method, which greatly reduces the computational complexity of the optimization process and realizes the optimal distribution of stiffened plates. In this paper, the global finite difference method is used to solve the topological acoustic sensitivity of the structure by using the fast multipole boundary element with high efficiency, taking the radiated sound power as the objective function and the element stiffness as the design variable. Based on the sensitivity distribution, the optimal region for increasing stiffness is obtained. Taking a spherical shell as an example, the sound radiation topology optimization of the structure under the action of harmonic force is analyzed. Based on the analysis of acoustic sensitivity, the radiated sound power of the structure is reduced by realizing the optimal arrangement of the ribs. In this paper, the main frequency of the noise is determined according to the test and analysis results of the noise power of the compressor. Taking the radiated sound power of the main frequency segment as the objective function, the topology optimization design of the compressor shell of the refrigerator is made, and the stiffness of the shell is improved by local reinforcement. By reducing the normal vibration velocity of the shell surface, changing the normal velocity distribution and reducing the acoustic radiation efficiency of the shell, the topology optimization of the distribution of the stiffened plate of the compressor shell is successfully realized, and the results of numerical simulation are verified by experiments. The effectiveness of the proposed method is demonstrated. The results show that solving the topological acoustic sensitivity based on the fast boundary element method improves the efficiency of solving the topological acoustic sensitivity, realizes the optimal layout design of the structural stiffened plate, and thus effectively reduces the radiated acoustic power of the structure. It is suitable for engineering application.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH45

【相似文献】