Numerical And Experimental Study On The Effect Of Dimple-Louvered Fins On Flow Efficiency In Compact Heat Exchangers

Numerical And Experimental Study On The Effect Of Dimple-Louvered Fins On Flow Efficiency In Compact Heat Exchangers

Numerical and experimental analyses are performed on a simple louvered and a dimpled-louvered fin bank geometry in low and medium Reynolds regimes to investigate the effects of dimples on flow efficiency which is a good representative of heat transfer rate. In order to properly investigate the flow characteristics, LES method is used to model the low Reynolds turbulence flow. Velocity field is discussed for various Reynolds numbers to obtain flow efficiency. A low turbulence wind tunnel with 460 x 460 mm cross section and 600 mm length for test section has been employed. In different Reynolds numbers the flow efficiency has been calculated numerically and experimentally by flow visualization method and the results show that dimples can increase flow efficiency more than 5% in fin banks. For higher Reynolds no this effect is more considerable because of more louver directed flow while in lower Reynolds no duct directed flow decreased this effect.