MODELING OF DROPLET BEHAVIOR DURING SPRAY FORMING USING FLUENT

A control volume based fluid dynamics software program, FLUENT, has be en used to model the 2-dimensional dynamic and thermal behaviour of Ud imet 720 droplets during gas atomization and spray forming. The effect of atomizing gas pressure, spray distance and melt mass flow rate (MF R) on the equilibrated droplet spray temperature has been examined and the predictions compared with measured maximum deposit temperatures f rom spray forming experiments performed under the same process conditi ons. The predicted spray temperatures at the substrate were consistent ly higher than the measured deposit temperatures, and in both cases in creased with: (i) decreasing gas pressure; (ii) decreasing spray dista nce; and (iii) increasing MFR. Individual droplet temperatures and vel ocities were found to be strongly dependent on droplet size with dropl et temperature decreasing and mean droplet axial velocities increasing with decreasing droplet size.