The Numerical Simulation Of Air Distribution Of The Underground Main Workshop In A Hydropower Station

Currently, there are three methods for predicting air distribution in underground hydropower station. They are jet formula method, CFD method and model experiment method Considering the great many merits of CFD method such as easily applying to complex geometric, independent of experiential parameters and easily simulate for many conditions and so on, this thesis use CFD method to study of the air distribution of certain pratical project. Choosing the turbulence model The correctness of the simulation are strongly dependent on the turbulent model you choose. More often, the standard k- ε turbulent model is used. But there are some disadvantages of it. In this article , the KNG- k-ε turbulent model is used which can make good result on transient flow and bend flow. A satisfying result is made though using this model. Simplify the problem and divide the mesh In numerical simulation, proper simplification of the physical problem can make the simulation simple. The object studying in this article is too large. The dimension is 53mX 15.4nX 15. 5m and the total mesh number is over one million which cannot be calculated by current personal computer. According the symmetry principle, minimize the model one third the size of the former model. The mesh number is greatly decreased which successfully solve theproblem of lacking of computer resource. Simulation for different types of air distributions The 3-D distributions of airflow and tenperature fields in large space are numerically calculated using the software of FLUENT. Through comparing the result of simulation, thinks that the delaminated air conditioning is better than the one of middle supply-up return air distribution. The air supply of low sidewall has large temperature efficiency and can supply the air with low temperature, as is a considerable type of air distribution.This thesis uses the CFD soft ware-FLUENT, realizes the simulation of airdistribution. The simulation offers guidance to the optional design of the air distribution of this type of problem.