超临界压力下国产航油RP-3导热系数的流动法测量

为了测量高温高压条件下航空燃料的导热系数,基于恒热流密度条件下,常物性不可压缩流体在圆管层流充分发展时的努塞尔数为常数原理,搭建了导热系数测量装置。通过牛顿冷却定律测量管内流体充分发展时的换热系数,可以在线测量流体的导热系数。经不确定度分析得到实验条件下最大相对不确定度为5.76%。使用乙苯和正十烷验对实验装置进行了标定,结果表明实验值与参考值比较的最大绝对偏差为5.36%。最后对2.5、3和3.5MPa下,不同温度范围的国产航油RP-3导热系数进行了测量。

Measurement of thermal conductivity of domestic aviation fuel RP-3 by dynamic method at supercritical pressure

In order to measure the thermal conductivity of aviation fuel under high temperature and press-ure,based on invariant heat flux condition and constant physical property hypothesis,Nu is a fixed valu-e when the fluid flow is fully developed,the thermal conductivity measurement device was built.The o-nline thermal conductivity can be achieved by measuring the heat transfer coefficient in the way of Newt-on's law of cooling when the fluid flow is simultaneously thermally and hydrodynamically fully develop-d in the horizontal circular tube.According to uncertainty analysis,the max relative uncertainty in this e-xperimental scope is 5.76%.Ethylbenzene and n-decane were used to calibrate experiment device,the res-ults showed that the maximum absolute deviation was 5.36%.And then the thermal conductivity of RP-3 was measured in the range of 310K to 410K at 2.5,3 and 3.5MPa.