Abstract: For existing problem of uneven spraying of mortar machine circle nozzle,a new kind of non-circle nozzle was designed.First,the speed changes and volume fraction changes of nozzle flow field were obtained by the CFD software Fluent and the Eulerian model in multiphase flow.On this basis,nozzle was optimized according to variance of speed and volume fraction.Then,more appropriate compressed air angle of incidence,number of compressed air inlet and tip of the nozzle length,width and thickness were selected.Finally,the nozzle structure to meet the requirements of automatic wall plastering machine was obtained.Finally,an optimized model sample made by 3D printing technology was test to verify optimized results.This study has important reference value for future optimization of nozzle of automatic wall plastering machine.

Key words: Fluent software, non-circle nozzle, multiphase flow, automatic wall plastering machine, variance