【摘要】 针对气流辅助式喷杆喷雾机的风助风筒原始设计中存在耗气量大、效率低、风速变异系数大的缺点,采用计算流体动力学(CFD)对风助风筒内外流场的三维区域进行了仿真。仿真结果表明:原型风筒内流场存在强旋流、流道窄的缺点,并导致工作外流场风速变异系数大。针对上述两种流场的问题,提出改进设计方案:对于外流场风速变异系数大的问题,采用减小出口尺寸和出口间距,可大大减小风速变异系数,但不能从根本上改变流场结构;为克服内流场强旋流、流道窄的不足,在上述结构参数优化基础上,增加导流板装置,减小速度变异较大区域的出口间距,最终优化结果满足设计要求。样机试验表明设计方案实现了高效和风速变异小的风幕。更多还原

【Abstract】 To improve the drawbacks of original designed air-assisted duct of boom sprayer,such as huge wind consumption,low efficiency,large coefficient variation(CV) of wind velocity,3-D flow field of interior duct and exterior free flow region was simulated by using computational fluid dynamics(CFD).Flow field analysis of the simulation results showed that there were strong swirling and narrow flow channel in the flow field of prototype air-assisted duct.It also resulted in large CV in exterior free flow field.In response to these shortcomings,two kinds of improvement designs were proposed.Firstly,the outlet size and outlets spacing was decreased to greatly reduce the CV of wind velocity,but could not fundamentally change the flow structure.Secondly,on the basis of above optimization,a flow deflector was added to overcome the strong swirling flow and narrow flow channel.Prototype testing indicated that final scheme achieved high efficiency and small wind speed variations.更多还原