一种高密度碳氢燃料替代模型及其热物性分析

Thermophysical Property Analysis and Surrogate Model of a High-Density Hydrocarbon Fuel

关键词:  高密度碳氢燃料  替代燃料模型  热物性参数  超临界态  多目标寻优

Key words:  High-density hydrocarbon fuel  Surrogate fuel model  Thermophysical property  Supercritical state  Multi-objective optimization

摘要:

针对一种应用于高超声速飞行器再生冷却的高密度碳氢燃料，提出适用于其超临界态流动及换热特性研究的替代燃料模型。基于实验获得的碳氢燃料高温裂解的产物组分及现有航空煤油替代模型，提出三组分替代模型，以多物性参数分子摩尔质量、密度、运动黏度、比热容和导热系数为遴选指标，通过多目标优化寻出一种替代燃料模型（71.1%反式十氢化萘、19.4%正十二烷、9.5%正十三烷）。基于碳氢化合物的混合热物性参数数据库（NIST SUPERTRAPP），通过二次开发对替代燃料模型的超临界态热物性进行预测和分析，发现在临界压力2.8MPa，临界温度700K附近，该种碳氢燃料的热物性参数变化最明显，并且随着压力的升高，变化逐渐变小。

Abstract:

The high-density endothermic hydrocarbon fuel was developed for the application of regenerative cooling in hypersonic vehicles， and a surrogate model of this fuel was proposed for studying fuel flow and heat transfer in supercritical state. A three-component model was chosen based on the product components captured in high-temperature pyrolysis experiments of this endothermic hydrocarbon fuel， as well as the surrogate models for current aviation kerosene. The molecular mass， density， kinematic viscosity， specific heat capacity and thermal conductivity were selected as the objectives， and the optimal surrogate model consisting of 71.1% trans-decalin， 19.4% n-dodecane and 9.5% n-tridecane was found by the multi-objective optimization method. The secondary development on the NIST SUPERTRAPP was applied to predict and analyze the thermophysical properties of the surrogate model in supercritical state， which showed that the most obvious change of thermophysical property was located around the critical pressure of 2.8MPa and the critical temperature of 700K. Besides， the change of that in the supercritical state decreased gradually with the increase of pressure.