车内辐射噪声计算的非连续等几何边界元法

Discontinuous isogeometric boundary element method in automotive radiation noise calculation

针对车内辐射噪声计算中几何和边界条件不连续的角点,连续等几何边界元法无法实现精准模拟,在角点处会有较大的计算误差问题,提出了一种非连续等几何边界元法.基于边界元中的“双节点”思想建立非连续单元,避免了法向量或变量值不连续的现象,解决了角点问题.利用非连续单元的特性将原包含强奇异积分的边界积分方程降为弱奇异,并使用并行技术加速计算.数值算例表明:与连续边界元和等几何边界元法相比,非连续等几何边界元法在计算精度和效率上均有显著提高.声压响应实验结果表明数值计算和实验结果高度一致,验证了该方法的正确性.

Corner problems where geometry and values of boundary conditions exhibiting discontinuities in automotive radiation noise calculation,cannot be calculated precisely using continuous isogeometric boundary element method and large calculation error problems at the corner nodes will arise,a discontinuous isogeometric boundary element method formulation was proposed,invoking the idea of“double nodes”in conventional boundary element method to avoid the corner problems,the discontinuity of normal vectors or variable values is avoided,and the corner problem is therefore solved.The strongly singular integral in the original boundary integral equation was reduced to weakly singular,and parallel techniques were employed to accelerate the proposed method.Numerical example of a car passenger compartment subjected to realistic boundary conditions illustrates that accuracy and efficiency of discontinuous isogeometric boundary element method has been improved obviously over continuous boundary element method and isogeometric boundary element method.Additionally,the sound pressure response experimental shows that the result of the numerical calculation agrees well with the test result,so the accuracy of the method is verified.