The Boeing Company

Thermal regulation of power systems is critical to the performance and durability of many aerospace platforms. Such regulation is frequently accomplished by heat exchangers that are custom-designed to meet challenging thermal and form-factor requirements. In many aerospace systems, such as commercial aircraft, weight, compactness, system integration and cost are major drivers in the value proposition for the systems. Consequently, the development of lighter weight and/or lower cost heat exchangers via the application of new materials and/or manufacturing processes is of tremendous interest owing to their potential to enable, for example, lighter aircraft and correspondingly reduced fuel consumption.

The Boeing Company is developing a next-generation air-cooled heat exchanger by leveraging technological advances in additive manufacturing (AM). The work builds on a previous ARPA-E IDEAS award to the University of Maryland that included the fabrication of geometrically complex heat exchanger coupons. Boeing subsequently demonstrated AM fabrication of thin-walled structures with a thickness of 125 to 150 microns, which represents a 50% reduction relative to then-state-of-the-art AM processes. The high temperature heat exchanger currently under development employs complex internal geometries to achieve an expected 20-30% improvement in thermal performance and up to 20% reduction in weight. Current manufacturing techniques include manual stacking of heat exchangers, brazing in a thermal vacuum chamber, and welding of external features. Each of these manufacturing steps is time consuming, expensive, and may damage the part. A validated AM process for heat exchangers could lead to fabrication cost savings well in excess of 25% by eliminating these steps. If successful, these high performance, lightweight heat exchangers would enable more energy-efficient aircraft. AM can also expand the design space for heat exchangers, enabling advanced designs that conform to challenging form factor requirements. Advances in efficient air-side cooling could also have significant spillover benefits in additional industries such as power plant and distributed energy systems, automotive, air-conditioning and refrigeration, power electronics, and chemical processing.