Claus Emmelmann

In aerospace, thermal applications demand compact, lightweight, and efficient heat exchangers. Additive manufacturing processes offer the potential to create highly complex structures that are not achievable through traditional manufacturing methods. This work presents the development of an additively manufactured fluid-fluid heat exchanger that shows the potential to enhance the performance, reduce weight, and increase compactness compared to a conventional plate heat exchanger. A numerical model of the conventional plate heat exchanger was created, and fluid dynamics simulations with heat transfer were performed. Validation of the simulations was done by experiments. Then, a novel heat exchanger was designed using a bottom-up approach and investigated at different levels of complexity using computational fluid dynamics. The internal structure of the final heat exchanger consists of a repeating triply periodic Schwarz diamond minimum surface elongated in the direction of flow. The heat exchanger was manufactured with laser powder bed fusion process using AlSi10Mg. It had a 108% higher compactness and 54% lower weight compared to the plate heat exchanger. Numerical analysis yielded the pressure loss in pascal was reduced by 50%–59% while heat transfer in watts was improved by 3%–5%. Future researches should experimentally investigate the thermal and fluid mechanical characteristics of the novel additively manufactured heat exchanger and increase compactness and heat transfer further by analyzing the minimum partition wall thickness and the impact of wall roughness and deposit formation.