弧形体挠性接管声学传递损失计算与分析

Theoretical calculation and analysis of transmission loss of flexible arc pipe

为提高弧形体挠性接管的声衰减能力,首先分析了管壁橡胶的粘弹性对其内部介质声速的影响;然后,基于一维声传播理论,推导了弧形体挠性接管的传递损失理论模型,并将理论计算值与有限元分析结果进行了对比;最后,利用弧形体挠性接管传递损失理论公式,分析了弧形体挠性接管结构参数对其传递损失的影响。研究结果表明:弧形体挠性接管内声速随频率增高而递增,以其中心频率为分界点,传递损失曲线分别向低频方向和高频方向移动;弧形体挠性接管传递损失的理论计算与有限元仿真结果在中低频率范围内吻合良好;减小弧形管的壁厚可使其传递损失曲线向低频移动;减小弧形曲率半径能够增大弧形管的传递损失;增加弧形管的长度,可以增加弧形管的传递损失,同时使其传递损失曲线向低频移动。

To improve the acoustic transmission loss of flexible pipe,the influence of flexible arc pipe on the speed sound of inner fluid is analyzed.The transmission loss theoretical model of flexible arc pipe is proposed based on one-dimensional plane wave theory.The calculated values are contrasted with the three-dimensional finite element model(FEM)acoustic simulation results.The influence of structure parameters of flexible arc pipe on its transmission loss is analyzed according to the theoretical formulas of transmission loss.The findings are shown as follows:The speed sound of inner fluid increases with frequency,and the flexible arc pipe′s transmission loss curve moves towards lower and higher frequency,with its center frequency as a dividing point.The theoretical calculation and FEM acoustic simulation results are found to be in fair agreement in low and medium frequency.The transmission loss curve moves towards lower frequency with the decrease of shell thickness while the transmission loss can be improved with the decrease of curvature radius.The transmission loss curve moves towards lower frequency and the transmission loss increases as well with the increase of the length.