论文部分内容阅读
通过实验装置研究了系统压力对水平管内超临界碳氢燃料RP-3流动换热特性的影响规律,并对管内燃油径向热物性变化、浮升力以及热加速对流动换热特性的作用机理进行了分析.结果表明:管内燃油表面传热系数随主流温度升高而增大,不同系统压力下,燃油在相同无量纲温度点热物性变化速率的不同导致了表面传热系数和Nux峰值的差异;燃油主流温度与内壁温度之间的差异而导致的热物性差别是造成管内换热规律变化的主要原因,浮升力和热加速作用对换热特性的影响可以忽略;无量纲参数Grq/Grth可以更好地反映超临界压力碳氢燃料RP-3在水平管内的沿程流动换热特性变化规律.
The influence of system pressure on the flow and heat transfer characteristics of supercritical hydrocarbon fuel RP-3 in horizontal tubes was studied by means of experimental equipment. The mechanism of radial thermal property change, lift force and thermal acceleration on the heat transfer characteristics of flow in the tube was studied. The results show that the surface heat transfer coefficient increases with the increase of the mainstream temperature, and the difference of the thermal transfer coefficient and the Nux peak at the same dimensionless temperature is caused by the different system pressures . The difference of thermal properties caused by the difference between the main fuel temperature and the inner wall temperature is the main reason for the change of heat transfer rule in pipe. The influence of lift force and thermal acceleration on heat transfer characteristics can be ignored. The dimensionless parameter Grq / Grth Which can better reflect the changing rule of the flow and heat transfer characteristics of supercritical pressure hydrocarbon fuel RP-3 in the horizontal pipe.