【摘要】 边界元法用于计算轴对称管道及消声器内部声场与管口声辐射问题.对内部域和外部域有效的边界积分方程由管口处的连续性条件来耦合.轴对称边界积分方程被简化为沿母线的积分.采用三节点二次等参元对具有外插进出口管的膨胀腔消声器的传递损失、厚壁圆管内外声场及圆直管的辐射阻抗进行了计算并与其它方法结果进行了比较.作为应用实例,文中对简单膨胀腔消声器的插入损失进行了计算.更多还原

【Abstract】 The BEM is applied to calculating the acoustic field in axisymmetric ducts and mufflers as well as the sound radiation from open end.The pair of boundary integral equations which is valid for the interior and exterior domain is coupledby continuity conditions at opening.The surface integral can be reduced to an integral along the generator.The transmission loss of expansion chamber muffler with extended inlet and outlet, the interior and exterior acoustic field of a duct, the radiation impedance of sound from circular pipe have been calculated using quadratic isoparametric element with three nodes and compared with the results obtained by means of other method.Take an example, the insertion loss of simple expansion chamber muffler has been calculated.更多还原