Simulation Study On The Spray Flow Field Of Air Atomized Paint Spray Gun

Spray is a process that the liquid is jetted into the gas medium through a nozzle, scattered and fragmented into small droplets. Spray technology is widely used in industrial areas and people's daily lives. And air atomized paint spray gun is a kind of spray tools which used in automobile and household industry. After years of research and development, the design of spray gun is relatively mature abroad. But the research of domestic in this area has less achievement, and most of the designs depend on imitating the products of foreign country. The need of theories and methods in spray gun design is urgent.In this regard, this paper summarizes the development status and trends of air atomized paint spray gun, and the current research status of spray flow field at home and abroad. And modeling and simulation of the spray flow field are finished by CFD (Computational Fluid Dynamics) technology. Then it analyzes the change of characteristics under the different parameters. At last a test bench for testing spray pressure of the spray gun is built. Through the research above, some useful methods and suggestions are put forward in the spray gun design, especially the nozzle design.The whole paper consists of four sections:Chapter one is the introduction of this paper. It first introduces the development status and trends of air atomized paint spray gun, and summarizes the current research status of spray flow field. Then it points out the main subjects and contents of the research work. Meanwhile, it briefly introduces the overview of the CFD and Fluent software.Chapter two introduces the atomization mechanism and the basic structure and working principle of spray gun, and discusses the basic equations to model and simulate the gas flow field of spray gun. Then modeling and simulation are made. At last, the simulation results under different parameters are compared and analyzed.Chapter three discusses the two-phase (gas-liquid) simulation model of the spray gun flow field, modeling and simulation are made. At last the simulation results are analyzed.Chapter four puts forward a experimental program based on the scanning and reproduction to the spray surface pressure field. And a spray gun pressure field scan test bench is built. The simulation results are compared with the test results, demonstrate the validity of the simulation model.