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本文采用湍流模拟方法结合煤油的10组分替代模型对国产RP-3航空煤油在水平圆管中的超临界态流动及对流传热特性进行了研究.湍流模拟采用RNGk-两方程模型以及增强壁面处理方法,煤油热物性和输运参数的确定基于10组分替代模型,并采用广义状态对应法则(ECS)结合考虑真实气体效应的Benedict-Webb-Rubin方程计算.同时,通过网格无关性研究以及与煤油加热圆管实验数据的比较验证了数值方法的可靠性.在本文研究的流动条件下,对于壁面热流为1.2和0.8MW/m2的算例,当管壁温度略超过煤油的拟临界温度时将发生传热恶化现象,并且恶化程度随着热流密度的降低而减小;而在壁面热流为0.5MW/m2时则不再出现传热恶化.通过分析传热恶化前后近壁区湍流强度可知,传热发生恶化以及传热性能的再次恢复与近壁湍流强度的变化有关.经典的传热公式如Sieder-Tate公式、Gnielinski公式可以基本反映亚临界区煤油的传热关系,但不能预测煤油的传热恶化现象.而考虑超临界特性的Bae-Kim修正公式可以描述煤油的传热恶化.另外,研究发现:当煤油进入超临界态时,管道摩擦阻力将显著增加.
In this paper, the supercritical and convective heat transfer characteristics of domestic RP-3 aviation kerosene in a horizontal tube were studied by turbulent simulation combined with the 10-component alternative model of kerosene.The turbulence model was simulated by RNGk-two equation model and the enhanced wall The treatment method, kerosene thermophysical properties and transport parameters were determined based on the 10-component substitution model and calculated by the generalized state correspondence rule (ECS) combined with the Benedict-Webb-Rubin equation considering the real gas effect. At the same time, And the comparison with the experimental data of kerosene heating pipe to verify the reliability of the numerical method.With the flow conditions studied in this paper, for the case of wall heat flow of 1.2 and 0.8MW / m2, when the pipe wall temperature slightly exceeds the kerosene to be critical The heat transfer will be worsened at the temperature, and the degree of deterioration will decrease with the decrease of the heat flux density. When the wall heat flow is 0.5MW / m2, the heat transfer will no longer be deteriorated. By analyzing the turbulence The intensity shows that the deterioration of heat transfer and the renewal of heat transfer performance are related to the changes of the intensity of turbulent flow near the wall.The classical heat transfer formulas such as Sieder-Tate formula, Gnielinski formula Which can basically reflect the heat transfer relationship of kerosene in the subcritical zone, but can not predict the heat transfer deterioration of kerosene.Bae-Kim correction formula considering the supercritical characteristics can describe the deterioration of kerosene heat transfer.In addition, the study found that: Critical state, the pipeline friction resistance will be significantly increased.