Ansys12.0CFX官方教程14A.ppt

Chapter 14 Advanced Physics Overview,Introduction to CFX,Combustion,A wide range of models are available to simulation combustion reactions Eddy Dissipation Model suitable for fast reactions Finite Rate Chemistry Model suitable for slower reactions Single and multi-step reactions Laminar Flamelet Model suitable for diffusion flames (reaction occurs only at the flame surface) NOx and Soot models,Combustion combined with the SAS turbulence model,Combustion,Extended Coherent Flame Model Used for premixed or partially premixed combustion, where fuel and oxidizer do not immediately burn when mixed Includes wall quenching capability, where reaction stops when mixture touches a wall Recommended for Internal Combustion Engine studies,Combustion,Residual Material Model Unburned reactants from one combustion cycle can be burned in future cycles Can be used to model Exhaust Gas Recirculation Auto-Ignition When fuel and air is at sufficiently high temperature, ignition occurs Used for modelling compression-ignition engines (diesel engines) Can be used to predict premature ignition (“knock”) in spark-ignition engines,Particle Tracking,For simulating droplets and particulates Liquid sprays, solid particles erosion Breakup models simulate spray breakup after injecting from a nozzle Particle evaporation, e.g. spray drier Particle reactions, e.g. coal combustion Particle collisions Wall film modeling,Spray injection and wall film formation on a hot wall, followed by evaporation,Stochastic particle collision model,Internal Combustion Engines,A large range of capabilities in particle tracking, mesh deformation and combustion come together in the si