一种间接测量惯性管阻抗的方法

惯性管是脉冲管制冷机的一个重要部件,需要保证其在脉冲管热端提供合适的阻抗幅值和相位。如何准确确定惯性管阻抗一直是个难点。本文利用直线压缩机背腔内压力波动计算体积流率,从而间接得到惯性管入口体积流率,进而得到惯性管阻抗特性,并与DeltaEC计算做了详细对比,为进一步优化脉冲管制冷机打下基础。本文首先介绍了惯性管的热声计算模型及其湍流修正方法,并详细介绍利用压缩机了测量体积流率的方法。实验中重点考察了频率、惯性管入口压力波动、气库体积大小对阻抗的影响,并对实验结果进行了分析。实验结果表明,阻抗幅值及相角跟湍流模型计算结果总体而言相当吻合,但在某些区域还需进一步修正。

An Indirect Method for Measurement of Inertance Tube Impedance

The inertance tube is an important component of the pulse tube cooler,which must provide appropriate impedance amplitude and phase at the hot end of pulse tube.It is still difficult for direct measurement of the impedance through experiments.In this paper,an indirect method is introduced.Using a linear compressor to drive the inertance tube,the impedance could be deduced through measurement of the piston swept volume due to the interaction between compressor dynamics and the tube impedance.A series of experiments with different frequencies,inlet pressure wave amplitudes and reservoirs have been done.The results have also been compared with calculations based on DeltaEC software,which shows relatively good agreement.