求解声辐射问题的微分求积法与微分求积单元法
The differential quadrature method and differential quadrature element method for the acoustic radiation
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摘要: 基于无限域中的Helmholtz波动方程,将微分求积法与微分求积单元法应用于二维及三维声辐射问题的求解,对最外层节点施加不同阶数的人工边界条件,区域内使用均匀及非均匀的节点分布方式,分析了节点分布方式及人工边界条件对计算结果的影响,比较了两种数值方法的计算精度。研究结果表明:微分求积法与微分求积单元法,前者精度更高,而后者耗时更少,在频率较低时,具备较高的效费比。人工边界条件对计算结果的影响主要体现在低频段,而节点分布方式的影响主要体现在高频段。非均匀的节点分布方式在不同频段都具备更好的计算精度。Abstract: Based on the Helmholtz equation in unbounded domain, the differential quadrature method and differential quadrature element method were applied to the calculation of two-dimension and three-dimension acoustic radiation. The different orders of artificial boundary conditions were applied to the nodes in the outer layer, and the uniform and nonuniform node distributions were used in the calculation domain. The influence of different node distributions and approximate boundary condition orders on the numerical results was presented. And the precision of these two numerical methods was compared. The results show that for the differential quadrature method and differential quadrature element method, the former has the higher precision while the latter has the less calculation time and quality benefit-cost radio in the low-frequency. The approximate boundary conditions are mainly taking effect in the low-frequency, while the nodes distributions are mainly taking effect in the high-frequency. The nonuniform node distribution has the higher precision in the different frequencies.