Performance analysis of a compound heat exchanger by screening its design parameters

Manufacturers of heat exchangers are continuously searching for new and better designs. A promising approach is to combine known enhancement techniques, resulting in so-called compound heat exchangers. In this paper the air-side of a round-tube heat exchanger with louvered fins and delta winglet vortex generators is studied. The contribution of five important design parameters to the thermal hydraulic performance of the compound heat exchanger was numerically investigated. Knowing which parameters have the biggest influence is important for the optimization. To limit the number of simulations, the Taguchi method was used. At high inlet velocities the performance is mainly determined by the louvers, while at lower inlet velocities also the delta winglet geometry has a significant contribution. To validate the simulations, an aluminum compound heat exchanger was made and tested in a wind tunnel. This validation experiment showed that there is an acceptable match between the numerical results and measurements.