Abstract: Computational fluid dynamics and theoretical fluid dynamics, experimental fluid dynamics together constitute the fluid mechanics research field. With the development of computer science and technology, and the progress of mathematical theory and numerical method, computational fluid dynamics (CFD) is gaining more and more attention by researchers and engineering technicians. The prediction accuracy of CFD theoretical model is widely recognized, and CFD has become a research tool for complex flow and heat transfer problems, and an important design tool used in engineering fields and teaching tool of thermal fluid mechanics. CFD method has applied in vacuum engineering as a research tool to investigate the working mechanism of vacuum equipment. Numerical study of inner flow behavior in a steam-jet vacuum pump was carried out, the simulation results was analyzed to reveal the effect on the pumping performance by CFD approach, which can be used to optimize the structure and improve performance of the steam-jet pump.

Key words: computational fluid dynamics, steam ejector, flow behavior, numerical simulation