响应面法优化空气喷嘴雾化流场的数值研究

Numerical Study on the Optimization of Atomization Flow Field in Air Nozzle Using Response Surface Methodology

为提高空气喷嘴的喷涂性能,采用计算流体力学对空气喷嘴与喷涂面之间的雾化流场进行数值模拟,并结合响应面法对喷嘴的结构参数与工况参数进行总体优化。首先搭建热线风速仪测速实验台验证数值计算模型的准确性,然后设计三因素的中心复合试验,建立以塑形气孔斜面倾角α、环形气孔压力p1、塑形气孔压力p2为设计变量,以喷涂面中心压力pc为目标变量的响应面回归模型与数学优化模型,进而对喷嘴的结构参数与工况参数进行优化,求得喷嘴特征参数的最优组合。结果表明:利用响应面法对喷嘴特征参数进行优化设计可有效改善喷嘴的雾化流场,优化后的喷涂面中心压力降低了57.6%,有利于均匀喷涂;通过分析响应面图,可总结出各特征参数对喷涂性能的交互影响规律。

In order to improve the spraying performance of the air nozzle,the atomization flow field between air nozzle and spray surface was numerically simulated by using computation fluid dynamics(CFD),and the structure parameter and operating parameters of the nozzle were optimized globally combined with the response surface methodology.Firstly,a hot-wire anemometer measuring system was set up to verify the accuracy of the numerical calculation model.Then,a three-factor central composite experiment was designed to establish the response surface regression model and mathematical optimization model with the inclination angleαof shaping air holes,the pressure p1 of annular air hole,the pressure p2 of shaping air holes as design variables and the center pressure pc of spray surface as target variable.Furthermore,the structural parameter and operating parameters of the nozzle were optimized,and the optimal combination of nozzle characteristic parameters was obtained.The results show that the optimization design of the characteristic parameters of air nozzle by response surface methodology can effectively improve the atomization flow field in the nozzle,the central pressure of the spraying surface after optimization is reduced by 57.6%,which is conducive to produce uniform coatings.By analyzing the response surface graph,the interaction law of each characteristic parameter on the spray performance can be summarized.