在流动管道中有限振辐波的传播

THE PROPAGATION OF WAVES WITH FINITE AMPLITUDE IN FLOW DUCTS

本文讨论了在流动管道中有限振幅波传播的一种计算方法。该方法基于:(1)如果知道管道某位置的压力和速度的同步时间历程:利用特征线方法,就能计算管道任何位置的压力和速度的时间历程。(2)由于速度时间历程的测量难度很大,故利用管道上相邻两点的压力同步时间历程来计算该两点的速度时间历程。(3)速度的初值可用控制流量,多次迭代计算得到。(4)管端参数λ和β是研究管端反射的重要参数。本方法取得了理论与实验结果十分一致的良好结果。

This paper discusses a numerical technique and acomptuer progran developed for the prediction of the acoustic energy propaga-tion with finite amplitude in flow ducts.The investigation shows that(1)In order to apply the method of characteristics to predict wave propa-gation in a uniform duct,one requires a simultaneous pressure and avelocity time history record,observed at some reference plane acrossthe duct.(2)It is difficult to obtain a velocity time history record.Itcan be calculated from a pair of pressure time history records fromadjacent wall-mounted pressure transducers spaced certain apart on thepipe.(3)In order to get a velocity time history record,one also requirean initialn velocity which can be calculated from controling mass flux.(4)To study wave reflection at an open pipe termination,one requiresβandλwhich can be calculated from this paper.This paper presents a second-approximation method which has withthe more calculating points.The results show that the theory agreesexperiment.