National Aeronautics and Space Administration

Glenn Research Center

Dennis Huff

“Future Challenges in Aeropropulsion”

Dennis Huff, deputy chief of the aeropropulsion division, gave a presentation on the future challenges in aeropropulsion. More specifically he spoke on aeronautics research on engine systems and how they can be improved. Improvement to these systems is focused on noise reduction, reduced emissions, better fuel economy, and (in the case of supersonic aircraft) reduced shock strength. Investigation of these new systems is the focus of the “Fundamental Aeronautics Program.” The program is split into four main areas of focus: subsonic propulsion systems, supersonic propulsion systems, hypersonic propulsion systems, and rotorcraft.

The first topic Huff outlined was subsonic propulsion systems and how they can be improved. He started with projected improvements of through 2025. He went on to discuss different ways these improvements can be achieved and the status of the technology and research. He even briefly mentioned advanced concepts (n+3 timeframe – 2035) and the general trends of engine improvement that can lead to the projected goals.

The second topic Huff discussed was supersonic propulsion systems. In this case one needs to be mindful of acceptable sonic boom intensities on the ground. Huff outlined different developing technologies to help solve the problems associated with faster than sound flight over urban areas. An important area of focus is on variable cycle nozzles for jet noise reduction.

The third topic was hypersonic propulsion systems. Huff talked about the turbine based combine cycle engine and how it converts between turbine and scramjet. He demonstrated how the transition was being demonstrated by having a series of doors on the inlet that can change the shape of the shock during the transition.

The final topic Huff talked about was rotorcraft. He mentioned there is a major focus on variable speed engines to increase the travel speed and improve efficiency at the same time. The power turbine speed changer is a major technological component that needs to be developed.

Huff ended his talk with some closing thoughts on future developments. He specifically mentioned major industry accomplishments that would be important and new game changing technologies that have yet to be developed.