The study on the effect of offset flow control in wavy fin heat exchanger

In this study, the effect of offset length on a heat transfer performance in the offset applied wavy fin heat exchanger is assessed numerically. Numerical simulations are performed with non-dimensional steady governing equations. The working fluid are water and flow pattern is laminar in range of 100≤ Re ≤400. The geometry of simulations is 20 degree-five waved wavy fin. The parametric studies are performed to find optimum offset length and figure out the flow characteristics of internal flow. The offset is applied at third wave only. As a result, In case of Offset length 0.2Dh is the best case and heat transfer performance increase about 27%. Offset length 0.25Dh is the second-best case and heat transfer performance increases about 26.5%. The heat transfer performance is enhanced because of the offset flow control that makes relatively low temperature fluid at the middle of the channel attached to high temperature wall. The heat transfer performance of offset length 0.2Dh is especially superior to that of offset length 0.25Dh because the low temperature fluid flows less to recirculation zone. Once the offset applied at all wave, the heat transfer performance of offset length 0.2Dh enhances 3% greater than that of offset length 0.25Dh.