Numerical Simulation Of Spray Characteristics And Heat Transfer Characteristics Of A Pressure Swirling Nozzle

Spray cooling has many advantages.It is widely used in the electronic components,laser technology,the spray drying,gas trapping and other industries.The droplet diameter,velocity and wall heat transfer coefficient are important factors to determine the spray cooling effect.Therefore,it is significant to study the atomization characteristics and heat transfer characteristics of spray cooling.In this paper,the ANSYS FLUENT software is used to establish the three-dimensional numerical models of the atomization field.Based on the DPM model,the effects of spray pressure,spray height and spray angle on the droplet velocity,diameter and DPM concentration were analyzed;Simultaneous the effect of the nozzle distances is also discussed.The results show that when the spray pressure increases,the SMD decreases,the velocity and the volume flux increase;When the spray height increases,the change of droplet diameter is not obvious,and the average velocity becomes smaller.When the tilt angle is increased,the change of the droplet SMD is little,and the proportion of droplet with smaller velocity increases.The concentration of DPM on the right side of is equal to that of 0 degree,while the left droplet concentration is significantly smaller.With the change of the distance between the nozzle and the nozzle,the range of the interference area of the nozzle is changed,so the characteristic diameter of the nozzle is gradually smaller.When the nozzle spacing becomes larger,the range of interference between the spray becomes smaller,and the uniformity of the spray droplet distribution becomes worse.When the heat transfer is considered,the influence of the liquid film thickness,the heat transfer coefficient and the wall temperature on the heat transfer characteristics are analyzed.The results show that the heat transfer coefficient increases,the average temperature is lower,and the thickness of the liquid film decreases when the spray pressure increases.There is an optimal value of spray height.When the spray height is 6mm,the heat transfer effect is best,and the average wall temperature is lowest.When the spray angle is 30 degrees,the average wall heat transfer coefficient is the highest,the average temperature is lowest,and the temperature distribution is relatively uniform;When the nozzle spacing is small,the heat transfer in the atomization area is relatively uniform.The wall surface heat transfer coefficient is decreased with the increase of nozzle distance,but the temperature is increased.The spray cooling effect is better than liquid film flow,its heat transfer coefficient and wall temperature is lower.