超临界压力下航空煤油在并联管中流量分配特性

研究了超临界压力下国产航空煤油RP-3在竖直并联U型管中的流量分配特性,分析了工质温度、系统压力以及加热热流密度不对称性对流量分配特性的影响规律.其中实验段内、外径分别为1.8mm和2.2mm, 实验中质量流量保持为4g/s,系统压力变化范围为3~5MPa,热流密度变化范围为q=60~240kW/m2. 实验结果表明:较低系统压力下,等热流密度加热至管路油温达到拟临界温度附近时会诱发支管流量的较大变化,从而导致并联管系统各支路流量的重新分配;加热不均对支路流量的影响非常显著;另外,提高系统压力可以有效抑制并联管系统中各支路流量分配失衡,增强系统的稳定性. 

Characteristics of flow distribution of aviation kerosene in parallel pipes under supercritical pressure

Flow distribution characteristics of China No.3 kerosene (RP-3) in vertical parallel U-turn tubes were experimentally investigated under supercritical pressures.Based on the experimental results,the effects of temperature,pressure and asymmetrical heat flux to the flow distribution characteristics of the RP-3 were analyzed.In the experiments,the inner and outer diameters of the test tube are 1.8mm and 2.2mm respectively;the mass flow rate is maintained at 4g/s under the pressure from 3 to 5MPa,and the heat flux changes from 60 to 240kW/m².The test results indicate that static unsteady phenomenon will be induced when fuel temperature is close to its pseudo-critical point under the lower pressure,which leads to flow imbalance and flow redistribution between the two tubes.In addition,the mass flow in the branch tube is significantly affected by the non-uniformity of heat flux,and the system stability can be improved effectively by the increase of pressure and which will inhibit the flow distribution differences in the parallel pipes.