SBIR-STTR Award

ELAS (Electric Lift Augmenting Slats) is an eSTOL technology that combines leading-edge slats with a series of small electric ducted fans (EDFs) accelerating the air between the slat and the airfoil. The core of the ELAS concept is the combination of two technologies. In 2016 CubCrafters began experimenting with a specialized leading-edge slat to lower the takeoff speed and distance of their aircraft and enhance low-speed maneuverability. Analysis as done using CFD, with units built and flight-tested on a manned research aircraft. The stock craft could take off in 100' with the slat lowering this by 35%. This technology has resulted in a patent disclosure and is at TRL 5. Parallel to, and independent of the CubCrafters Slat project, Ullman (PI) also began a privately funded project in 2016 to study Electric Ducted Fans (EDFs) enhancing the upper surface flow much like the Boeing's YC-14 and NASA QSRA, but with distributed electric propulsion. Extensive wind-tunnel testing showed increases in all lift curve characteristics, Clo, Cla, and Clmax. Typical Clmax increases of 117% were seen, implying a potential halving of the takeoff distance. In-flight tests with the JabirWatt (a Jabiru J260 modified for the project), with its 12% EDF coverage, showed a 16% increase in Clmax, resulting in an 8% decrease in the stall speed. This project has resulted in a patent, Distributed Electric Ducted Fan Wing (10,099,793), October 2018, and is currently at TRL5. The combination of these two technologies in ELAS has potential greater than the sum of their parts but is at TRL 1-2. ELAS's potential will be explored in the proposed research with the development of a baseline configuration complete with performance estimates for a STOL mission and CFD tools for future optimization bringing the concept to TRL 3-4 Potential NASA Applications (Limit 1500 characters, approximately 150 words) Beyond the evident importance to CubCrafters, potential applications within NASA include humanitarian aid delivery via aircraft requiring STOL capability; development of a low-cost aerial vehicle for exploration with acquisition and operation costs less than many unpiloted vehicles currently in use; and ELAS application for advanced off-field capability with piloted, optionally-piloted, and unpiloted CubCrafters aircraft. From a research perspective, ELAS is a distributed electric propulsion QSRA technology. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) For CubCrafters and other STOL manufacturers, market drivers are centered on aircraft that provide true STOL performance while also offering best in class useful load and cruise speeds. By the core nature of this innovation's purpose, ELAS is directly positioned to enhance all aspects of STOL operations: takeoff, climb, approach and landing, enabling further utility and larger safety margins

Electric Lift Augmenting Slats (ELAS) is a combination of leading-edge slats and a series of small electric ducted fans (EDFs) accelerating the air in the gap between the slat and the main body wing airfoil. The ELAS Concept provides: JATO-like (Jet Assisted Takeoff) electric-powered boost on takeoff and climb out, descent and landing speed reduction, steeper approach angles, and improved low-speed margins and handling qualities. ELAS can be added to an existing airframe or built into the wings as original equipment. It can even be designed as retractable when not in use. Rather than the EDFs being used to solely add thrust, ELAS also provides a dramatic increase in lift by increasing the speed of the air over the top surface of the wing, a form of upper-surface-blowing. This work is built on earlier successful projects combined with recent advances in distributed electric propulsion. The distributed, small electric ducted fans alter the airflow over the wing in ways not possible with two internal combustion engines (the Custer channel-wing) or multiple large turbines (the Boeing YC-14 and the NASA QSRA). Further, ELAS can provide improved low-speed aircraft control through both the increase in maximum lift and stall angle, and differential power distribution. Command of the power distribution has the potential to reduce loss-of-control (LoC) during critical low-speed periods and provide improved handling qualities during gusts. While there is a big push to develop eVTOL aircraft, ELAS offers a much shorter path to near-eVTOL capability. This claim is supported by the following Phase I findings: 1) A variety of small aircraft equipped with ELAS can takeoff and approach/land with near-helicopter-like profiles. 2) Can be attached to existing aircraft or built into new aircraft: lower acquisition and recurring costs than eVTOL. 3) 50%-100% more range with more payload than comparable eVTOL. 4) next-gen battery technology is not required. 5) Uses Off-The-Shelf hardware. Potential NASA Applications (Limit 1500 characters, approximately 150 words) Potential applications within NASA include humanitarian aid delivery via aircraft requiring STOL capability; development of a low-cost aerial vehicle for exploration and transportation with acquisition and operation costs less than many unpiloted vehicles currently in use; and ELAS applications for advanced off-field capability with piloted, optionally-piloted, and unpiloted CubCrafters aircraft. From a research perspective, ELAS has significant potential as a distributed electric propulsion Quiet Short-Haul Research Aircraft (QSRA) technology. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words) Market drivers for CubCrafters & similar manufacturers are centered on aircraft that provide STOL performance while also offering best-in-class useful load & cruise speeds. By the core nature of this innovation's purpose, ELAS is directly positioned to enhance all aspects of STOL operations across the industry: takeoff, climb, approach & landing, enabling further utility & larger safety margins.