激光光内复合送粉送丝熔覆气固两相流流场数值模拟

Numerical Simulation of Gas-Solid Two-Phase Flow Field of Laser Cladding with Coaxial Inside-Beam Composite Powder and Wire Feeding

应用ANSYS FLUENT 12.0软件的离散相模型,对研制的新型激光光内送粉、送丝复合喷嘴气固两相流流场进行了三维数值模拟,分析了保护气入口压力、载气流量等参数对流场的影响。模拟结果表明:激光光内送粉、送丝熔覆时,外围保护气对粉束有很好的集束、准直作用。保护气入口压力越大,粉末的集束效果越明显。而载气流量过大将造成粉末颗粒流在离喷嘴较远处发散角变大。

In this study, using dispersed phase model in ANSYS FLUENT 12.0, the gas-solid two-phase flow field of the developed new type of laser coaxial inside-beam composite powder and wire feeding is three-dimensionally numerically simulated. The effects on the flow field from inlet pressure of shielding gas and the carrier gas flow rate are analyzed. The simulation results indicate that during the coaxial inside-beam powder and wire feeding laser cladding, peripheral shielding gas has very good concentration and collimation effects on the powder beam. The higher the inlet pressure of shielding gas is, the better the powder beam is concentrated. However, too high carrier gas flow rate leads to an enlarged divergence angle of the powder grain flow which is a little far from the composite nozzle.