Performance Comparison of Modified Offset Strip Fins Using a CFD Analysis

Offset strip fins (OSF) have been widely used in plate-fin heat exchangers. Conventional OSFs are constructed with plain fins. Various design modifications to improve the performance of OSFs are compared here. The modifications suggested include perforations, dimples, vortex generators, and a double-layer design. The performance capabilities are evaluated using a computational fluid dynamics (CFD) analysis. The performances are compared in terms of the j-factor, f-factor, area goodness factor, and volume goodness factor. The f-factors of all modified designs appeared to be higher than that of the plain OSF, while the j-factor was found to be higher or lower than that of the plain OSF depending on the design modi fication used. The plain OSF has the largest area goodness factor, while OSFs with multiple perforations and dimples show a higher volume goodness factor than the plain OSF.