单管传输特性的改进模型与实验研究

Modified model for transmission characteristic of single tube and its experimental verification

为了描述单根圆形管道的传输特性,在流体网络理论的基础上,参考Rott的波动方程和Swift对紊流的修正方法,提出单管传输特性的改进模型.在模型中讨论了流动为紊流时的修正方法:当R/δv较小时,利用Swift的修正方法进行修正;当R/δv较大且修正因子n>1时,利用n对紊流进行进一步修正.为了对模型进行验证,以声压放大器这一典型的单管道为例开展了实验研究.紊流时在R/δv较小的情况下,改进模型和DeltaE的计算结果一致,与实验吻合良好;在R/δv较大的情况下,改进模型由于充分考虑了径向上的对流换热损失,其计算结果与Del-taE相比更加接近实验结果.

A modified model was proposed based on the fluid network theory,Rott＇s wave equation,and Swift＇s correction method for turbulence in order to describe the transmission characteristic of a single circular tube.The correction methods for turbulence were discussed.Swift＇s correction method is used when R/δv is small,and further correction is made using factor n when R/δv is large and n1.An acoustic amplifier was taken as example.The calculation results of the turbulence flow at small R/δv by the model and DeltaE agreed well with the experimental results.When the flow was turbulent at large R/δv,the results of the model were closer to the experimental results than DeltaE because the model considered convective heat transfer loss in radical direction.