CAJ | 학술논문

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。
무화분취시분사성형기술적관건부건，위험증분취결구대무화성능적영향，채용계산류체동역학방법연구불동Laval분관후구결구、도류관추정각화돌출장도대분사기체류장급도류관정단정압강(ΔP)적영향규률。결과표명재설계긴우합Laval분취중：원각과도식후구형상비첨각급주체과도경리우획득고속기류；교소적추정각가이감소도류관출구정압치，단속도쇠감교대；도류관돌출장도재7~8 mm시가이획득교호적기동효과。최후선정원각과도Laval형출기구형상，도류관추정각β=45°이급돌출장도h=8 mm가공무화분취병진행무화실험，재무화압강0.8 MPa시7055합금분말이구상혹류구상형태존재，질량중경위42.3μm。
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.