Abstract: Considering the deficiency of the physical parameters for endothermic hydrocarbon fuel in the research of aerospace propulsion systems，a density measuring device with a gas driven piston was designed for the density measurement of RP-3 aviation kerosene. The density values of the kerosene in the temperature range from 293K to 673K and the pressure range from 1.2MPa to 4MPa were experimentally measured，and the density varying with temperature and pressure was analyzed. Besides，a method based on the Peng-Robinson equation of state was derived for density calculation of real fluid，and the calculation process was calibrated based on the existing density data of n-decane (C10H22). Finally，the computational density values of the RP-3 aviation kerosene were found to be slightly lower than the experimental results，especially in low-temperature and near-critical stage. It is mainly caused by the limitations of this computational method for calculating the density of mixtures.

Key words: Density measurement；Equation of state；Supercritical；Critical parameters

摘要： 为了逐步改善高性能空天动力装置研究中液态碳氢燃料物性数据缺乏的现状，设计了一种气动活塞式的密度测量装置，对压力和温度范围分别为1.2～4.0MPa和 293～673K的常用液态碳氢燃料——RP-3航空煤油的密度进行了实验测量，并分析了其密度随温度和压力的变化规律。此外，基于PR状态方程进行了真实流体的密度计算，并结合已有的正癸烷(C10H22)密度实验数据对计算过程进行了修正。通过将采用修正后的方法计算出的RP-3航空煤油的密度值与实验测量值进行对比，发现计算值比实验值稍低，尤其在低温阶段和临界点附近。分析认为，这主要是由于此计算方法用于混合物计算时的局限性造成的。

关键词: 密度测量；状态方程；超临界；临界参数