清洗用扇形喷嘴结构参数对其内部射流的影响

Research of Influence on Internal Flow Field of Structure of Fan-shaped Nozzles Used in Water Jet Cleaning

采用标准k-ε湍流模型,利用计算流体软件对扇形喷嘴的内部流场进行了数值模拟;研究了当扇形喷嘴出口投影面积一定时,入口结构、出口几何参数对喷嘴内部流场和出口射流速度的影响。研究表明:锥形入口结构最有利于射流在喷嘴内的加速,可使射流在喷嘴中始终处于加速运动状态。出口段的直径影响出口段内射流的速度,出口射流速度随出口圆柱段直径的增加而增加,但存在影响其变化趋势的一个阙值直径。出口盲端的长径比和V形切槽的夹角对喷嘴内射流流态无明显影响,对出口射流速度也无明显影响。

Adopting the standard k-ε turbulent flow model, the internal flow field of the fan-shaped nozzles with different structural parameters were simulated using computational fluid software. Keeping the projected area of the nozzles orifice constant, the influence on their internal stream flow state and velocity of the stream at the orifice of the nozzles＇ different inlet structure and geometrical parameters of outlet were studied. The results are as follow ： taper inlet structure facilitates the acceleration of the stream which assures the stream to be accelerated all the time uring moving in the nozzle. The velocity of the stream at the orifice increases as the diameter increases correspondingly, but there exists a critical value of the diameter which influences the increasing trend of the velocity of the stream, the ratio of length to radius of the blind end and the angle of the V-shaped groove have no significant influence on the flow field of the stream and the velocity of the stream at the orifice.