A Turbo-Brayton Cryocooler for Aircraft Superconducting Systems

Hybrid turbo-electric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft design space by decoupling power generation from propulsion. Resulting aircraft designs such as blended-wing bodies with distributed propulsion can provide the large reductions in emissions, fuel burn, and noise required to make air transportation growth projections sustainable. The power density requirements for these electric machines can only be achieved with superconductors, which in turn require lightweight, high-capacity cryocoolers. We have developed a Cryoflight turbo-Brayton cryocooler concept that exceeds the mass and performance targets identified by NASA for superconducting aircraft. In Phase I of this project, we will extend our initial design study and develop modeling tools to support a system-level optimization and individual component designs. We will focus on the critical component for mass reduction?the recuperative heat exchanger?and perform risk reduction activities to demonstrate the feasibility of our concept for this component. In Phase II, we will design, build, and test a compact, lightweight, high-performance recuperator for the Cryoflight cryocooler. This development effort will provide an enabling technology for the superconducting systems needed for hybrid turbo-electric aircraft to be feasible.