介质弹性对风洞液压控制系统影响的分析与测试

电液伺服系统广泛应用于风洞各种执行机构的控制中。随着风洞试验技术的发展，以及对机构小型化的要求，电液伺服系统的工作压力、控制精度不断提高。这种情况下，液体的弹性是不能忽略的。本文提出对液体体积弹性模量进行测试的两种工程方法，并进行了实际测量。对于风洞常用电液伺服系统，液体体积弹性模量在900～1000MPa。针对某风洞执行机构调试中发生的问题，利用油液弹性模量的测量结果进行了计算、分析，结果与现象吻合。

Influence of the fluid elasticity on hydraulic systems in the wind tunnel and its measurement methods

The electro-hydraulic systems are widely applied in control of many kinds of mecha- nism in wind tunnels. With the development of wind tunnel test technique, and the requirement of miniaturization of the structure, the working pressure and the control precision of the hydraulic servo systems need to be improved. Under this condition, the elasticity of the fluid can not be neglected. In this paper, two engineering oriented methods of measurement of the module of elasticity are presented, and applied to the experiment in the lab. It shows that the module of elasticity of the fluid is in the range of 900MPa to 1000MPa in hydraulic systems in wind tunnels. The results are used in analysis of the problem accounted in a new built model supporting mechanism in a supersonic wind tunnel. The calculation keeps accordance with the Dhenomencn.