FINNED ELLIPTIC TUBES HEAT EXCHANGERS IN THE TURBULENT REGIME CONSTRUCTAL DESIGN

This work seeks numerically the heat exchanger structure direction of evolution in time, i.e., the general optimal that maximizes the total heat transfer rate between a fixed volume arrangement of finned tubes and a turbulent external flow governed by a pressure difference, both for circular and elliptic tube arrays. In this way, the dynamic, ever-changing heat exchanger design that provides easier access to the currents that flow through it is sought for any time reality (e.g., geometry, materials, environment), according to Constructal law. The optimization procedure began by recognizing the limited availability of the design space as a fixed volume constraint. The three-way optimized (3wo) arrangement concerning tube-to-tube distance, eccentricity, and fin density was found as (S/2b, e, ϕf)3wo ≅ (0.5; 0.4; 0.094). A relative heat transfer gain of up to 38% was noted with the elliptic compared to the 3wo circular arrangement, demonstrating that elliptical tube arrangements have potential for considerably better performance and lower cost than traditional circular arrangements.