Currently,in the world wide industry,the most popular fin design of automotive heat exchangers is the louver type.However,its noticed in the industry that the fundamental researches of the fins on airside is pretty rear due to the difficulties of the tiny structures.This paper aims at employing Computational Fluid Dynamics(CFD)methodology to reveal the airflow characteristics of the louver fins and try to find connections to the macro performance of the coils.Based on 1:1 scale of 10 louver fins as a group in detailed geometry,to represent an overall heat exchanger,conduct simulation to explore the airside key heat transfer characteristics of the fins,including heat transfer flux,airside pressure drop,Reynolds number distribution at different louver angles etc.The findings have been validated with the tested data.Illustrations of the airflow pattern through the fins and louvers have been presented and an animation video of the air stream flow has also been created for tutorial purpose.