A Computational Fluid Dynamic Modeling Analysis of Bladeless Air Curtain Performance to Save Cooling Load in Light Rapid Transit

摘要

The cooling loads of air conditioning systems in public transportation have high energy consumtion to achieve human comfort standard. This study was focus on computational fluid dynamic approach analysis the Bladeless Air Curtain Unit (BACU) of the automatic door in light rapid transit (LRT) for saving cooing load. The installation the Bladeless ACU as a variable is obtained by vertical installation in a horizontal position on the top of the doorway. The inlet air sources of the Bladeless ACU on the same side of installation or opposite side installation are studied. The geometry model was a redesign from a commercial the Bladeless fan. The diagonal ratio was the ratio between the long of airfoil size to the wide of cross section airfoil; they are 2.5, 3.33, 5 and 10. The airflow speeds from the outlet of airfoil were varied; they are 5, 10, 15 and 20 m/s. The other parameter was the slit thickness varied 1, 1.5, 1.75, 2, 3 and 4 mm. The simulation result was showed that the discharge ratio decrese significantly while the airflow speed less than 10 m/s. The optimum velocity in varied gradient temperature between inside and outside carriage of LRT was found as corresponding to the highest performance of air curtain barried efficiency. The current study resulted that the performance of horizontal installation was reached 81%.