对流条件下环境压力对液滴蒸发的影响研究

通过建立单液滴蒸发的物理数学模型,采用数值方法研究了对流环境中压力对液滴蒸发的影响.模型中考虑了蒸发过程中液滴与周围气流物性随温度、压力的瞬态变化.在比较验证计算程序可靠性的基础上,以正庚烷燃料液滴在氮气中的蒸发为例,模拟计算了弱对流与强对流热条件下,环境压力不同时燃料液滴半径与温度的瞬态变化,分析了液滴蒸发的环境压力影响.研究结果表明,对初始温度较低的燃料液滴,压力对蒸发的影响与热环境密切相关,在不同的对流热环境中,压力的影响作用明显不同.

Effects of ambient pressure on fuel droplet evaporation in a convective environments

This paper explores a physical and mathematical model for the evaporation of a single droplet.The effects of ambient pressure on fuel droplet evaporation in different convective thermal environments was investigated using numerical methods.The evaporation model took account of instantaneous changes in physical properties of droplets,such as fuel droplet radius,and changes in gas flow with changes in temperature and pressure.The reliability of the computational program was checked.Then the evaporation of an n-heptane droplet in nitrogen gas flow was simulated.Two kinds of thermal environments-weak convection and intensive convection-were considered.The results show that the effects of ambient pressure on droplet evaporation are significantly dependent on the thermal environment.The effect of pressure differs a lot between weak convection and intensive convection conditions.