基于CFD的清洗用扇形喷嘴清洗参数研究

Study in Cleaning Parameters of Flat Fan Nozzle Used in Cleaning Based on CFD

扇形喷嘴因其均匀的扁平射流能提供其较大的清洗面积而被广泛应用在工业清洗中。打击力和动压是衡量清洗效果的重要参数，合理的匹配喷嘴直径、压力、流量，能更有效、更节能地进行清洗作业。在建立了扇形喷嘴及其外流场的三维模型的基础上，运用FLUENT的VOF两相流模型对不同出口直径的扇形喷嘴在不同压力下的打击力、动压进行了比较分析。结果表明：喷嘴直径和压力的增大都会使打击力增大，但不是二者越大打击力的增大的幅度就越大；同一个扇形喷嘴，射流压力在1～21 MPa之间，打击力会随着压力的增大而增大，但增大的幅度会随之减小，如3 mm喷嘴射流压力从1 MPa提升到2 MPa射流打击力增加率为101％，但从20 MPa提升到21 MPa射流打击力增加率只有5％；相同的射流压力下，扇形喷嘴出口直径在1～3 mm之间，打击力会随着出口直径的增大而增大，但增大的幅度会随之减小，如射流压力为2.5 MPa喷嘴出口直径从1 mm提升到1.5 mm射流打击力增加率为118％，但从2.5mm提升到3 mm射流打击力增加率只有42％。

Flat fan nozzles are widely used in industrial cleaning because of their large cleaning area provided by their uniform flat jet.Dynamic pressure and strike force are important parameters weighing cleaning efficiency, and reasonable matching nozzle diameter, pressure, and flow can make cleaning operations more efficient and save more energy.On the basis of established the three-dimensional （ 3D） model of fan nozzle and the external flow field, using FLUENT＇s VOF two-phase flow model to analyze and to compare the fan nozzles with different outlet diameters under different pressure, the strike forces and dynamic pressure were gotten.The results show that the nozzle diameter and pressure increase will both make strike force increase, but not the bigger of both of them, the higher rate of increase of strike force will be.With the same flat fan nozzles, jet pressure between 1~21 MPa, strike force will increase with in-creasing of pressure, but the magnitude of the increase will decrease.For example, the increase rate of jet strike force of 3 mm-nozzle is 101%from 1MPa to 2 MPa of jet pressure, but from 20 MPa to 21 MPa, it is only 5%.Under the same jet pressure, fan nozzle out-let diameter between 1~3 mm, strike force will increase with increasing of outlet diameter, but the magnitude of the increase will de-crease.For example, the increase rate of strike force under 2.5 MPa of jet pressure is 118%from 1 mm to 1.5 mm of increase, but from 2.5 mm to 3 mm of increase is only 42%.