Performance optimization of a wavy finned-tube heat exchanger with staggered curved vortex generators

Abstract

A novel configuration of staggered concave curved vortex generators is proposed for thermal performance enhancement in a wavy finned-tube heat exchanger. The change of transverse location of the couple of concave curved vortex generators is out of synchronous. The effect of different transverse locations of the concave curved vortex generators on the thermal performance is numerically reported. Results showed that the stagger-arranged concave curved vortex generators can generate counter-rotated longitudinal vortices and enhance the heat transfer. Compared with the wavy smooth channel and the wavy channel with plane vortex generators, the overall performance of the wavy channel with concave curved vortex generators is greatly improved. Nusselt number and the thermal performance factor of the proposed vortex generator arrangement can increase by 30.4% and 25.9%, respectively. Optimization of the vortex generator arrangement is carried out using a multi-objective genetic algorithm and neural network. The optimal transverse distances are calculated using the Pareto optimal strategy. The heat transfer power Qv can increase by 34.6% under the same pump power Pv. Correlations of Nu, f, and the optimal Qv and Pv are presented for engineering applications.