DAVID G. ULLMAN
eSTOL - electric Short Take-Off and Landing
The Promise of Air Taxis
Wind Tunnel Capabilities
Vortex Generators
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eSTOL - electric Short Take-Off and Landing
There is a significant upside to electric propulsion, especially for STOL aircraft. Ullman has been exploring this concept for the last four years. A summary of his project is given in his 2019 presentation at the Sustainable Aviation Symposium (SAS 2019) at Berkeley.
The IDEAL Project
(Integrated Distributed Electric-Augmented Lift)
Ullman's interests are primarily on electric aircraft propulsion, specifically distributed electric propulsion. Part of the IDEAL project is flight testing the JabirWatt. Click on the image of the JabirWaat for details on it and on the button below for details on IDEAL .
U.S. Patent 10099793: The Distributed Electric Ducted Fan Wing
The Distributed Electric Ducted Fan Wing concept incorporates multiple electric ducted fans on lifting surfaces configured to provide integrated aerodynamics and propulsion resulting in enhanced aerodynamic characteristics and thus aircraft performance. The concept uses a plurality of electric ducted fans (EDFs) to not only provide thrust, but to also blow air across the upper surface of a substantial portion of the lifting surface area increasing lift at little loss in efficiency. Not only can the total lift on the surfaces be enhanced, but the lift distribution managed: to aid in aircraft control; ameliorate the effects of turbulence: reduce shed vortices; mitigate the effects of system failures; eliminate stalls; and compensate for crosswinds. This concept offers the potential for increasing electric airplane efficiency and performance, enhancing Short Takeoff and Landing (STOL) capabilities, improving passenger comfort, and reducing the structural stress and cost of aircraft.
The Promise of Air Taxis
2019 Presentations given at EAA Airventure, July 2019 (Click the title for copies of the slides)
May 2018 Keynote at the Sustainable Aviation Symposium
In May 2018, Ullman was invited to be the keynote speaker at the Sustainable Aviation Symposium. His presentation, Electric Air Vehicle Performance Prospects: Comparing eVTOL versus USTOL was well received and created much discussion. In this presentation he combined some early results on IDEAL with comparing Air-Taxi visions.
Comparing Air Taxi Visions
Based on his work on distributed propulsion he has been studying the potential for VTOL, multi-copters, and ultra-STOL as Personal Air Vehicles. He has written a major paper comparing these types of air vehicles. A summary of the paper and the full paper can be had by clicking on the graph on the right.
Vortex Generators
In 2012 Ullman finished building a Velocity SEFG. This effort took him six years and was built in a garage. In 2014 he completed experiments on the Velocity to improve its cooling using vortex generators. A copy of a paper is available here. In a reduced form it was published in Kitplanes magazine in December 2015. Since the paper was published many Velocity owners have reported a 50F drop in engine temperatures using this vortex generator design.