二氧化碳在RP-3航空燃油中扩散系数实验

Experiment on diffusion coefficient of carbon dioxide in RP-3 aviation fuel

基于压力降落法原理,搭建扩散系数测试实验装置,测试了298.15K时CO_2在水中的扩散系数并与文献值比较,验证了实验系统的可靠性。实验测定了密闭容器中283.15~333.15K时CO_2-RP-3燃油体系中的压力随时间的变化值。实验测量曲线与数值拟合曲线完全稳合,计算得出不同温度下气体在燃油中的扩散系数值为10-8 m2/s数量级。由实验结果可知:气体扩散系数与温度之间符合化学反应阿伦尼乌斯定律,由此根据已有扩散系数值可建立CO_2在RP-3燃油中扩散系数预测模型。采用253.15、263.15K和273.15K时3组实验数据来验证模型的准确性,结果显示实验数据符合预测模型方程,模型具有一定的外延性。

A experiment apparatus based on the pressure decltion method was constructed,and the preliminary results concerning the carbon dioxide-Water diffusion system at298.15 K were in reasonable agreement with other report.Then it was used to measure the gas pressure versus time for carbon dioxide-RP-3 aviation fuel system under a temperature range from 283.15 Kto 333.15 K.The fitting curve agreed with the experimental data perfectly,the diffusion coefficient values at different temperatures were of magnititude 10-8 m2/s.From the experimental result,the relationship between the mass diffusion coefficientand temperature satisfied the Arrhenius rate law.A model of prediction of diffusion coefficient of carbon dioxide in RP-3 aviation fuel was built according to existing data in the experiment.To verify the accuracy of the prediction model,more experiments under the conditions of 253.15,263.15 Kand 273.15 K were conducted.The experiment results matched the fitting equation with accuracy and extensionality.