THE EFFECT OF FIN PITCH ON A CROSS-CUT FLOW CONTROL IN WAVY FIN HEAT EXCHANGERS
The effect of fin height on a cross-cut flow control in wavy fin heat exchangers is accessed numerically. The concept of cross-cut is cutting fin in a direction perpendicular to the flow direction. A two-dimensional five-waved wavy fin with the space ratio (fin pitch divided by wavelength) 0.1 and 0.2 each are used as simulation domain. The flow Reynolds number is 100 for space ratio 0.1 case and 200 for space ratio 0.2 case. If the inlet flow velocity is assumed to be the same, the situation, where Re and space ratio increase simultaneously, means that the fin pitch is increased but the wavelength is the same. Comparing two flow cases, we can confirm the effect of fin pitch on cross-cut flow control. The corrugation angle of simulation is 20 degree in all cases. The simulation is performed using non dimensional governing equations for a steady laminar flow rate with water (Pr = 6). The cross-cut is applied at third wave only with 0.292Dh length. As a result, the heat transfer performance increased 3.77% more than typical wavy at the space ratio 0.1 and Re = 100 case and 19.85% more at the space ratio 0.2 and Re = 200 case. That is, as the fin pitch increases, the effect of cross-cut flow control increases.