Dr. Rodger Dyson has worked at the NASA Glenn Research Center for over 32 years in power, propulsion, and thermal technologies supporting both aeronautics and space missions. He currently serves as a power and propulsion technical lead developing megawatt scale electric aircraft propulsion, fault management, Mars nuclear electric propulsion, and lunar surface power. He also contributed to the James Webb Space Telescope cryocooler development and is currently leading the development of a high-power thermal energy management system to recycle aircraft powertrain waste heat using a new solid-state exergy amplification technology. He previously founded and served as the principal investigator for the NASA electric aircraft testbed, for a long-lived Venus surface duplex power system and for Glenn’s extreme environment rig. He also founded the Power and Propulsion Systems Alliance hybrid electric technical area team and served as domain lead for NATO hybrid electric aircraft technology.
A new thermal energy conversion power generation technology is presented that combines the historically higher power Brayton and lower power Stirling cycles into a new Strayton Quad cycle that has an overall higher system efficiency, specific power, and reliability than each individual cycle can achieve independently. The integration is achieved by installing an acoustic Stirling heat exchanger pair in the hollow shaft of a rotating Brayton cycle generator to provide both Brayton turbine conductive cooling and Brayton thermal recuperation. The Brayton cycle waste heat acts as a topping cycle delivering thermal energy to the shaft-embedded acoustic Stirling cycle. The four Strayton cycles are combined into a quad configuration to facilitate inter-stage cooling, reheating, and to complete a full acoustic wavelength multi-phase loop for significantly increased Stirling power, Brayton internal recuperation, and Brayton turbine cooling. The Brayton specific power and efficiency increases due to the higher allowable turbine inlet temperatures; quad configuration with inter-stage cooling and reheating; and a higher rotational speed when combined with a switched reluctance generator. The shaft-embedded acoustic Stirling specific power increases due to the quad self-amplifying acoustic loop configuration and the high power bi-directional acoustic turbine generators. The recuperator and heat exchanger masses are further reduced with two additional quad loops that provide Brayton stage inter-cooling and reheating with acoustic Stirling topping and bottoming cycles. The reliability increases because the system still operates even under multiple fault conditions, has no-contact seals and bearings, and can safely operate at much higher generator and fluid temperatures without exotic materials. The only moving parts are the rotating Strayton shafts and the rotating bi-directional acoustic turbine generators, which use pressurized gas bearings for long-lasting no maintenance operation. It specifically enables a new class of zero emission electric aircraft propulsion and a reliable higher system alpha electric spacecraft propulsion system. In addition, this technology provides the nascent terrestrial small modular nuclear power generation market with a higher efficiency fault-tolerant option.
The attendees will learn about a new invention that enables Megawatt scale Nuclear Electric Propulsion to Mars. It combines Brayton and acoustic Stirling technology into a new Strayton cycle. The new technology can also be used in terrestrial power generation applications as well.
