Maximization of heat transfer density from a single‐row cross‐flow heat exchanger with wing‐shaped tubes using constructal design

Abstract

AbstractA single‐row cross‐flow heat exchanger with wing‐shaped tubes is designed in this paper using the constructal design method. The wing‐to‐wing spacing and the wing thickness are free to morph while the chord of the wings remains constant. Wing‐to‐wing spacing optimization or heat transfer density maximization from the wings is the objective function in this design. Two directions of the free‐stream (incoming) flow are considered. The right‐ and left‐flow directions are considered with a constant drop in pressure. All wings are heated at a uniform temperature, and the air is used to cool these wings. The two‐dimensional conservation of mass, conservation of momentum, and the conservation of energy equations are solved by means of the finite volume method for steady and incompressible flow. The ratio of the wing thickness to the chord (dimensionless wing thickness) is changed from 0.2 to 1. For each wing thickness, three Bejan numbers (Be = 103, 104, and 105) are used in the numerical simulation. The results revealed that in the case of the flow direction to the left, the maximum heat transfer density is higher than that in the case of the flow direction to the right for all wing thicknesses and all Bejan numbers.