CFD-based shape optimization of a plate-fin heat exchanger

The plate-fin heat exchanger is common in aerospace applications because of its small size and lightweight. Heat exchangers are vital to aircraft applications such as jet engines, environmental control systems, and thermal management systems for electric components. The thermal management of waste heat from electric components in particular is becoming increasingly important as aircraft become more electric. Additionally, the prospect of new hydrogen-powered aircraft brings with it a new set of thermal management challenges. By minimizing the weight and drag penalties of heat exchangers, we can improve the overall efficiency of current and future aircraft. Analytical equations for heat exchanger performance are useful for rough sizing but lack the fidelity required to design improved shape configurations. In this work, we leverage gradient-based design optimization with high-fidelity CFD-based simulation to improve the detailed shaping of a plate-fin heat exchanger with plain fins. Furthermore, the results of our optimizations show that plate-fin designs optimized for minimum drag and mass differ substantially. The difference in mass between the drag-minimizing and mass-minimizing designs is largest (approximate to 50%) when the required heat load is largest. This suggests a greater potential mass savings for heat exchangers designed for higher heat loads. These results highlight the potential of gradient-based shape optimization methods to generate improved heat exchangers for weight-critical aerospace applications.