超音雾化中喷嘴结构对气体流场与雾化性能的影响  

Effect of atomizer structures on gas flow field in supersonic atomization

作　　者：司朝润[1,2] 王俊彪[1,2] 张贤杰[1,2] 袁帅[2] 

机构地区：[1]西北工业大学陕西省数字化制造工程技术研究中心,西安710072 [2]西北工业大学机电学院,西安710072

出　　处：《粉末冶金材料科学与工程》2014年第3期337-343,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51275420)

摘　　要：雾化喷嘴是喷射成形技术的关键部件，为验证喷嘴结构对雾化性能的影响，采用计算流体动力学方法研究不同Laval喷管喉口结构、导流管锥顶角和突出长度对喷射气体流场及导流管顶端静压强（ΔP）的影响规律。结果表明在设计紧耦合Laval喷嘴中：圆角过渡式喉口形状比尖角及柱体过渡更利于获得高速气流；较小的锥顶角可以减小导流管出口静压值，但速度衰减较大；导流管突出长度在7~8 mm时可以获得较好的气动效果。最后选定圆角过渡Laval形出气口形状，导流管锥顶角β=45°以及突出长度h=8 mm加工雾化喷嘴并进行雾化实验，在雾化压强0.8 MPa时7055合金粉末以球状或类球状形态存在，质量中径为42.3μm。Atomizer is the key component of spray forming. In order to investigate the impact of the structure parameters on the atomization performance, the computational fluid dynamics method was applied to study the flow characteristic （including gas velocity V and aspiration pressureΔP） of a Laval-type supersonic atomizer at different Laval nozzle throat structures, delivery tube tip angles and protrusion distances. Results show that in the three designed throat shapes such as：sharp-corner, smooth-corner and flat-corner, the comprehensive propulsion performance of the nozzle with smooth-corner throat is the best. For the studied atomizer, smaller delivery tube tip angleβcan reduce the aspiration pressure, but speed attenuation increases, and the atomizer with a protrusion distance h ranging 7~8 mm has better aerodynamic effect. For the smooth-corner Laval shape,β=45°; and h=8 mm are chosen for the atomizer used in the experiment, and rounded 7055 alloy powders with mass median diameter d50=42.3 μm are obtained by spray atomization progress at the atomization pressure of 0.8 MPa.

关 键 词：Laval管 导流管突出长度 锥顶角 抽吸压强 

分 类 号：TF123.2[冶金工程—粉末冶金]