The Numerical Simulation on Steam-Water Two-Phase Flow Field of Car Exhaust Pipe

The flow field of car exhaust pipe using ethanol gasoline has been researched, the continuity equation of a mixed two-phase model have been established by means of the mathematical model of two-phase flow field, and the simulation for the velocity distribution of droplets radial slipping in exhaust gas have been achieved. By using the divided grid and setting these four boundary conditions as conditions of the entrance, flow conditions at the end of the export, overflow conditions of the export, solid-wall boundary conditions, the iterative steps of calculation process and the relationship among the residuals of various parameters have been obtained. State of exhaust flow have been calculated using algebraic slip model (ASM),obtaining the distribution rule of the internal flow field in exhaust pipe for the disconnection of steam-water,and the characteristics relationship of separation for two-phase flow field of steam-water. The characteristic relationship among flow, split ratio and separation efficiency have been numerically simulated. The existence of the best range of split ratio for a particular exhaust pipe has been confirmed.