摘要
分析了旋芯喷嘴的雾化机理,运用三维相位多普勒粒子测速仪(3D-PDPA)设备测量了旋芯喷嘴喷出的细水雾雾滴速度及索太尔平均液滴直径(SMD)。试验结果表明,压力低于2 MPa时,喷雾状况符合表面波破碎理论规律。压力高于2 MPa时,喷雾在短距离内由旋芯强制呈空心锥形,最终变为引射方式下的实心锥形。随着喷雾压力升高,空心锥形形状保持的距离缩短。在空心喷雾阶段,随着喷射距离的增大,细水雾的轴向速度和径向速度在喷雾锥边缘处降幂下降。喷雾锥内部雾滴均系从边缘散溅所得,因此在各截面中心处,轴向速度服从普通射流规律,不存在稳定的径向扩散速度。雾滴SMD在各截面均远小于100μm。
Atomization mechanism of a type of nozzle is analyzed. The nozzle has a circular exit orifice, which is preceded by a swirl chamber with a multi-slotted, in-line distributor. Using three-dimensional phase doppler particle anemometer (3D-PDPA), water mist's velocity and Sauter mean diameter (SMD) is measured. Experimental result shows that the spray status at low working pressure can be explained by the wave breakup theory. When at high pressure, the spray is forced to a hollow cone by the distributor in a very short distance at first, and become a solid cone under stretch-jet way finally, such distance decrease with the rise of working pressure. On the status of hollow cone spray, with the extension of spray distance, water mist's axial and radial velocity decay exponential in the edge of spray cone. Mist inside the cone is caused by the splash of spray, so its axial velocity conform to the general rule of common spray, and a steady radial velocity is non-existence. Water mist's SMD is far less than 100μm in every section of the spray.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2004年第8期110-114,共5页
Journal of Mechanical Engineering
基金
国家自然科学基金(50005019)
国家'十五'科技攻关计划(2002BA208B04)资助项目。
