【摘要】 利用拉格朗日法,结合水滴蒸发模型和凝固模型建立了冰风洞内从喷雾系统喷出的水滴与冷气流之间动量、质量和热量交换的数学模型,利用上述模型计算了不同直径水滴随气流运动过程中速度、温度和直径的变化规律,讨论了空气相对湿度和喷嘴出口处水滴温度对水滴参数沿程变化的影响及低温条件下水滴参数的沿程变化。结果表明,小水滴相对于大水滴来说对空气流场具有更好的跟随性;蒸发作用会导致水滴尺寸减小,并且小水滴尺寸减小的程度比大水滴严重;提高空气相对湿度,降低喷嘴出口处水滴温度可以有效抑制水滴的蒸发,有利于保持水滴尺寸与含量的稳定性;当气流温度较低时,水滴会发生结冰现象,结冰的位置和结冰时间随水滴尺寸发生变化。更多还原

【Abstract】 Numerical simulation was conducted for the air and water droplets two-phase flow along the icing wind tunnel. The mass and heat transfer models between droplets and cold air were built by using Lagrange method.Besides,water evaporation and solidification models were also considered. The velocity,temperature and diameter variation of droplets with different size were calculated. The parameter variations in different initial conditions and low air temperature were also considered. The results show that the small droplets have greater tracing property to the air field than the bigger ones; without icing,the largest temperature difference between droplets and air is less than 1%in the test section; the effect of evaporation on small droplets is larger than that of bigger ones; increasing the air relative humidity and decreasing the spray outlet temperature can reduce the evaporation of drops; water droplets can ice under low air temperature,and the icing location and time depend on droplets size.更多还原