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为了给氧气/煤油发动机设计和热防护设计提供必要的设计参数,针对氧气/煤油燃气进行热力学计算。运用吉布斯最小自由焓计算模型得到燃气平衡组成,通过拟合公式的方法得到燃气的热物理参数及输运系数。通过计算,得到氧气/煤油燃气的组分及比焓、密度、比熵、粘性系数等热物理参数和输运系数随温度和压力的变化特性。分析结果表明:水离解对氧气/煤油燃气组分变化存在显著影响,压力增大会导致水离解起始温度升高;氧气/煤油燃气比焓、比熵、定压比热、粘性系数、热传导系数变化在温度较低时受压力影响较小,当水开始离解后,压力的影响显著增强;组分在燃气中的扩散系数同时受到了温度和组分摩尔分数的影响;燃气普朗特数变化受热传导系数变化的影响较大,水离解后,热传导系数的迅速增大使燃气的普朗特数迅速减小。
To provide the necessary design parameters for oxygen / kerosene engine design and thermal protection design, thermodynamic calculations were performed for oxygen / kerosene gas. The Gibbs free enthalpy calculation model is used to obtain the gas equilibrium composition. The thermal physical parameters and transport coefficients of the gas are obtained by the fitting formula. Through the calculation, the components of oxygen / kerosene gas and specific enthalpy, density, specific entropy, viscous coefficient and other thermal physical parameters and transport coefficient with the temperature and pressure characteristics. The results show that water dissociation has a significant effect on the composition of oxygen / kerosene gas. When the pressure increases, the starting temperature of water dissociation increases. The specific enthalpy of oxygen / kerosene gas, specific entropy, specific heat at constant pressure, viscosity coefficient, heat transfer coefficient The change is less affected by the pressure at lower temperature. When the water begins to dissociate, the influence of pressure is significantly enhanced. The diffusion coefficient of the component in the gas is affected by both the temperature and the mole fraction of the component. The change of gas Prandtl number The influence of the change of heat transfer coefficient is large. After water dissociation, the Prandtl number of gas decreases rapidly with the rapid increase of heat transfer coefficient.