Optimization of Fin Topology for Heat Transfer Within Lightweight Plate-Fin Heat Exchangers

This paper uses a multi-objective topology optimization method for thermal-fluid problems applied to the design of fins for primary use in plate-fin heat exchangers. The presented method was derived to obtain optimal fin topology for a wide range of design parameters and constraints, with the primary focus on aerospace applications. The performance of obtained fin topologies is evaluated based on the heat transfer and flow energy-loss objective functions. A level-set-based optimization is used, in which the sensitivity to the change in topology toward an optimal solution is obtained by the adjoint method. To reduce computational costs and allow for higher complexity designs, the design domain is reduced to a small two-dimensional (2-D) section of the overall fin structure. A three-dimensional (3-D) model is generated using 2-D topology optimization results, and the effects of model differences are analyzed. The results for various combinations of objective functions show similarity between the 2-D and 3-D models. Topologies consisting of multiple fins converge to a result that exhibits a novel cyclic motion of the topology, by which individual fins or segments of multiple fins cycle in a specific order. This behavior maintains the converged value of objective functions between cycles, indicating similarity among obtained topologies.