Numerical Simulation And Optimum Design Of Air Distribution By Chair Supplying In Theatre

The local air conditioning by chair, which is one kind of displacement ventilation systems, begins to be used in high-ceiling pubic building in China. In the displacement ventilation system, the air is supplied with less temperature than the ambient and extracted at ceiling level. The aim of this ventilation principle is to create supply air conditions in the occupied zone, while the air with traditional mixing systems is to create extract-air conditions in the whole room. The local air conditioning by air has the best performance in buildings with large space such as theatres. The design of air distribution is very important for ventilation by chair supplying in big space, while there is no standard of this now, especially of design for air distribution.With the development of the computer technology and numeric computing technology, CFD has been widely applied in designs and analysis of airflow organization in HVAC engineering. Making numerical simulations on indoor air distribution with CFD has lower costs, shorter cycles and more exhaustive data than with experiential jets formula or model experiment. This paper introduces the theory and realization of CFD, as well as the advantage and disadvantage of some CFD codes.A theatre is simulated, with FLUENT software. A hexahedral Cartesian grid was generated in Gambit. A standard k ? ? model is used together with the algebraic equation of eddy viscosity directly in the near-wall region. The Reynolds averaged Navier-Stokes (RANS) equation, and averaged energy and mass conservation equations, together with species transportation equation are discretized by finite volume method (FVM). The difference scheme is power law scheme. Boussinesq approximation and SIMPLE algorithm is adopted while control equations are solved on non-uniform staggered grid.In this way, the simulation results were obtained, such as velocity vectors, and the contours of velocity, temperature and relative humidity. With the comparison of difference cases, the best case was chosen.From the results of simulation, it is feasible to simulation air distribution in theatre with standard k ? ?model. This approach can help designers predict space airflow results, improve air distribution. This guarantee good results in a room air conditioning and improve indoor air quality, reduce energy consumption has important significance.