The geometric parameters of the D-jet spray gun are studied by numerically simulating the flow process of high-velocity oxy-fuel (HVOF) using computational fluid dynamics to predict their effects on the flow behavior of HVOF. The modeling results show that when the diameter of the parallel pipe is small,the flame velocity is high but the temperature is low. On the contrary,when the diameter of the parallel pipe is big,the flame velocity is slow but the temperature is high. And it is found that when the length of the parallel pipe is short(6,mm)or long(10,mm),the flame velocity is low but the temperature is up to 4,000,K,while when the length is 8,mm,the velocity is higher but the temperature is lower. It is also found that the flame velocity is lower than the sound velocity when the divergent angle of the gun is less than 1°.%以 D-jet 型喷嘴为研究对象，采用计算流体动力学方法对超音速火焰喷涂过程的火焰流进行数值模拟，研究喷嘴几何参数的变化对火焰喷射流的影响。研究发现，平行管的直径较短时，火焰的速度较高但温度较低；直径较大时，则刚好相反。当平行管长度为6,mm 和10,mm 时，火焰的温度可以达到4,000,K，但燃烧气流的速度较低；当平行管直径为8,mm 时，火焰的速度较高而温度较低。扩展角影响气体的膨胀，对火焰流的速度和温度影响较大。扩展角小于1°时，气体流动速度低，不能形成超音速流动。
展开▼
