Simulation And Experimental Study Of The Cold Air Attached Jet

The paper has chosen the air distribution of the directly expansible evaporation cold family central air conditioner as a research object. It has a similar character between the cold supply-air system and norm supply-air system. However, so far, it is mechanical to adapt to the norm temperature experimental data and experiential formulas to apply to the cold air distribution. Unfortunately, the methods can't reflect correctly the real condition of the cold air-conditioning air distribution. The paper has used the CFD to do simulative study between 9℃cold temperature supply-air and 16℃norm temperature supply-air.Firstly, the paper has used N-points momentum model to simplify the double supply-air shutter model. Then for the same floor under the evenly distributed heat source intensity condition, we have investigated the effects of varying the supply-air volume, the distances between the center of double shutter and the ceiling, heat source height on the cold supply-air jet's decay of velocity and temperature and on the separation from the ceiling. Finally, the paper has taken an actual cold temperature supply-air air conditioned room as the tested object, and has done a comparative analysis on the core velocity decay and the core temperature trajectory of the experimental and simulative results.The numerical simulative results of the cold temperature supply-air and norm temperature supply-air indicts that the cold temperature supply-air jet is easier to sink than the norm temperature supply-air jet under the same supply-air volume. For the identical supply-air temperature, the greater the supply air velocity is, the farther the distance of going down and the separate point of air jet are. When h/H₀ is different, the temperature decay of 9℃cold temperature supply-air jet is slower than that of 16℃ norm temperature supply-air jet. With the increase of the heat source height, the eddy intensity near the wall corner opposite to the supply-air jet is more obvious. When X/D₀ is less than 6, the velocity decay is greater with the increase of the heat source height. Through the experiment, the result of the used Realizable k-ε model is identical for the experimental result of the cold temperature supply-air system.