高压交变流动下热线风速仪标定方法研究

热线风速仪是重要的测速手段之一,但在高压交变流动条件下缺乏有效的标定方法。提出了一种通过测量气库内压力变化并按绝热热力学过程计算进出气库气体流速从而标定热线风速仪的方法。为了对该标定方案的误差进行分析,建立了该标定方案的数值模型,运用CFD软件FLUENT对该方案气库壁面分别设为绝热和等温边界条件时的热力过程进行了数值模拟,结果表明标定方案中采用绝热物理模型所引起的误差最大不超过2%。由于在热线探针两侧布置了一定量丝网作为均流元件,热线探针所测速度与管路截面平均速度误差不超过1.4%。该标定方法总误差不超过3.37%。

Investigation on calibration method of hot-wire anemometer in high pressure reciprocating flow

Hot-wire anemometer is one of the most important velocity measuring device,but there is no good calibrating method in reciprocating flow.A calibrating method is presented when a hot-wire anemometer is used in reciprocating flow by measuring the pressure of the gas reservoir.Thermal process of the gas in the reservoir is assumed to be adiabatic process.In order to analyze the error of the presented calibrating method,a numerical simulation was carried out by the CFD software FLUENT at the adiabatic and isothermal boundary conditions respectively.The numerical results show the error of the usage of adiabatic physical model in the calibrating method is smaller than 2%.Because of the arrangement of stainless-steel woven wire screens at two sides of the hot wire probe,the difference of the velocity measured by hot-wire anemometer and the average velocity of the cross section of the tube is less than 1.4%.The total error of the calibration system is smaller than 3.37%.