Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
The goal of this investigation is to apply Taguchi and Grey relational methods, to a concentric heat exchanger application, in order to optimize the design parameters. Coil spring types of the turbulators are used in the experimental study. The design parameters are; Reynolds number (3000 ≤ Re ≤ 10000), outer diameter of the springs (Ds = 7.2, 9.5 and 12 mm), number of the springs (Ns = 4, 5 and 6) and the incline angle of the springs ( = 0, 7 and 10). Nusselt number and friction factor are the results of the study. As a result, the effects of Re, , Ns, and Ds on Nusselt number is found to be 79.9%, 3.11%, 1.70% and 13.8%, respectively. Furthermore effect of all told four parameters on friction factor is found as 56.72%, 2.98%, 13.16% and 22.57%.