| At all times and in all countries,in order to shape beautiful,the use of functions and other reasons,some of the housing structure are often designed as circular arc shape,oval shape and inclined structure etc.How to create comfortable indoor environment for these envelope structures with special shape,a new challenge is put forward to the design of air distribution distribution.The suitable comfortable environment needs reasonable air distribution,which can not only create a comfortable heat and humid environment for indoor occupants,but also provide a high air quality,and reduce the energy consumption of the system.Based on the years of research and accumulation for vertical wall-attached air curtain ventilation in the research group,this paper presents the application of attached air curtain ventilation to the brachistochrone curved wall was chosen as representative research for various curved surface,and to the inclined wall room,the “twice impingement” ventilation mode based on the attached plane jet.Using Computational Fluid Dynamics(CFD)method to simulate and analyze the three air supply mode,and study its applicability,air distribution and indoor thermal comfort.(1)For attached air curtain ventilation based on the brachistochrone curved wall room,the variation of velocity field and temperature field under different curvature,air supply velocity and temperature was studied,and compared and analyzed the vertical and horizontal axis velocity,temperature and regularity of air distribution.Meanwhile,the paper also compared the vertical and horizontal axis velocity at the isothermal condition,the vertical and horizontal axis temperature under non isothermal temperature of brachistochrone curved wall room and vertical wall room.The paper also obtained the engineering design method through the research production got from the air curtain ventilation based on the vertical wall.The results show the attached air curtain ventilation based on brachistochrone curved wall can form “air lake” phenomena of velocity and temperature in the work area,which is similar to the displacement ventilation.Therefore,attached air curtain ventilation can be applied to the room of brachistochrone curved wall.(2)For the attached air curtain ventilation based on inclined wall room under winter condition,the effect on the velocity field and temperature field of three inclination angle β,three kinds of air supply velocity and temperature was studied,and evaluated the indoor thermal comfort.The results show that the inclination angle β had a great influence on the velocity field,temperature field and thermal comfort under the same condition,the attached air curtain ventilation mode could be applied to the building space with inclined wall for relatively high air supply velocity in winter condition,so this ventilation mode for inclined wall room in winter was not the best choice.(3)In view of the space layout and the use of demand,the SST k-ω turbulence model was used to simulate all kinds of cases for the “twice impingement” ventilation mode based on the attached plane jet.The effect on velocity field and temperature field of the different outlet position,different air supply velocity and temperature was studied,and evaluated the indoor air distribution.The outlet in the lower middle position had a better performance in air distribution for different conditions,when the air supply velocity was u0=3m/s,the air jet could not form "twice impingement " in the room,but “plunge into” the indoor work area after attaching a distance at the top of the room,which was similar to the mixed ventilation.Only when u0=5m/s,stable “twice impingement” ventilation mode based on the attached plane jet could be got.However,this ventilation mode easily caused sense of draught in occupied zone,so application of this air supply mode should pay special attention to solving the problem of sense of draught. |
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