飞机热气防冰系统笛形管流动特性研究OA

To address the issue that the Perry correlation does not account for the coupled effect of orifice scale and gas temperature,leading to significant design deviations under complex operating conditions and failing to meet the detailed design requirements of modern aircraft anti-icing systems,a variable-temperature piccolo tube flow test platform was established,and a full-process one-dimensional simulation model for the piccolo tube was constructed.Systematic investigations were conducted on the discharge coefficient and pressure drop characteristics under different orifice diameters and pressure ratios within the temperature range of 20℃to 260℃.The results indicate that the Perry formula exhibits notable deviations under both normal temperature(20℃)and high temperature(260℃)conditions,with maximum relative errors in mass flow prediction reaching 12%and 10%,respectively,failing to accurately describe the flow variation law over a wide temperature range.The discharge coefficient increases monotonically with the pressure ratio.The macroscopic variation is essentially the result of the competition between the microscale effect and the high-temperature viscous effect.At normal temperature,the orifice scale effect dominates:the smaller the orifice diameter,the larger the discharge coefficient.At high temperatures,the gas viscous effect is significantly enhanced,forming a complex interaction with the scale effect.Based on multi-condition experimental data,a new empirical correlation for the discharge coefficient was fitted,comprehensively considering the pressure ratio,temperature,and geometric dimensions.The prediction accuracy of the new correlation is better than 4%within the experimental range,reducing the error level by more than 60%compared with traditional correlations.The new correlation meets the high-precision design requirements of aircraft hot-air anti-icing systems.