بررسي بازه عملكردي پراب دو حسگري فيلم داغ استوانه اي موازي در جريان هاي معكوس

Evaluation of the Range of Performance for a Probe Consisting of Two Parallel Hot-Film Cylindrical Sensors in Reverse Flows

Abstract- Hot wire Anemometer (CTA) can be used to measure instantaneous flow velocity with high frequency. Since the principle of opearation of CTA is based on convective cooling, determination of the air flow direction is difficult. In this Research paper, we have used two cylindrical hot-film sensors placed in parallel to determine the flow direction. The wake effect and the heat due to the upstream sensor on the downstream sensor has been used to identity the flow direction. Effect of wake and presence of the upstream sensor on the downstream sensor has been studied. The results have been used to construct a probe consisting of two parallel sensors, sepereated by 1mm distance. Performance of the probe has been evaluated at various flow angles for laminar and turbulant flows. Findings of this study show that this probe provides the best performance at ±10 0 flow angles. Keywords: Hot Wire Anemometer, Cylindrical Hot Film Sensor, Reverse Flow. Wake, Thermal Effect. av