Abstract：To solve the problem that water was easy to splash into automobile air condition from external circulating inlet on rainy day, CFD method was utilized to simulate the motion course of raindrops from inlet grille on external circulating ventilate cover of air condition to external circulating inlet with air flow. The mechanism of external circulating water intake for automobile air condition was also discussed. The simulation models were built up separately according to position of inlet grille on external circulating cover of air condition, opening area of grille and opening shape of grille. The motion morphology of air flow was optimized to reduce the amount of external circulating water intake within permissible range of intake resistance. The results show that motion morphology of air flow, size of raindrops and rainfall intensity are major affecting factors on the amount of external circulating water intake for automobile air condition. When the distance between inlet grille and inlet is enlarged with reduced opening area of grille and changed opening shape of inlet grille, the water intake at external circulating of automobile air condition may be decreased.
2017, Vol. 38 
