Simulation of Atomization Gas Flow Field During Constrained Spray Deposition Process

Double disks controller was used to constrain the size of spray plume. The flow field characteristics of the constrained spray technology under different gas inlet pressures were simulated by the computational fluid dynamics (CFD) software "Fluent", and the simulation result was experimentally verified. The results show that with the increase of atomization gas inlet pressure, the speed of reverse gas flow increases, and thus, the temperature of the nozzle tip decreases. In this case, solidification of the melt in the nozzle occurs. When the inlet pressures of the gas and metal are 2. 5 X 10(5) Pa and 2. 0X10(4)Pa respectively, the pressure acting on the melt decreases to minimum value of about 8. 99 X 10(3) Pa. At this condition, the molten metal flows out smoothly and no apparent oxidation phenomena appear in the deposition billet. Moreover, the effect of atomization is the best and the width of the deposition billet is exactly consistent with the width of the wheel groove of continuous extrusion machine.