Coupled Aero-Propulsive Design Optimization Of a Boundary Layer Ingestion Propulsor

Speaker: Justin Gray, Propulsion Systems Analysis Branch, NASA Glenn Research Center
February 18, 2018

Presentation

Abstract

Airframe-propulsion integration concepts that use boundary layer ingestion have the potential to reduce aircraft fuel burn. One concept that has been recently explored is NASA's STARC-ABL aircraft configuration, which offers the potential for fuel burn reduction by using a turbo-electric propulsion system with an aft-mounted, electrically driven boundary layer ingestion (BLI) propulsor. So far, attempts to quantify this potential fuel burn reduction have not considered the full coupling between the aerodynamic and propulsive performance. To address the need for a more careful quantification of the aeropropulsive benefit of the STARC-ABL concept, we run a series of design optimizations based on a fully coupled aeropropulsive model. A 1D thermodynamic cycle analysis is coupled to a RANS simulation to model the aft propulsor at a cruise condition. A series of design optimization studies are performed, using gradient-based optimization with adjoint analytic derivatives, to minimize the required cruise power assuming different relative sizes of the BLI propulsor. Results show that the BLI configuration offers 6% to 9% reduction in required power at cruise, depending on assumptions made about the efficiency of the power transmission system between the under-wing engines and the aft propulsor. This design optimization based on computational fluid dynamics is shown to be essential to evaluate current BLI concepts, and provides a powerful tool for the design of future concepts.

Biography

Justin Gray holds a B.S in Aerospace Engineering and an M.S. in computer science. Since 2007, he has worked as a propulsion system analyst and multidisciplinary optimization specialist in the Propulsion Systems Analysis Branch at NASA Glenn Research Center. Since 2010, he has led NASA's OpenMDAO development team, overseeing framework development and applications in propulsion modeling, aircraft design, trajectory analysis, and wind energy. Currently, he is also a Ph.D. candidate in the Department of Aerospace Engineering at the University of Michigan.

Seminar Participation

Attending In Person

For select seminars, you may wish to attend in-person if you are in the vicinity of NASA Ames Research Center. These AMS seminars are held in Building N258 in Room 127, just off the front lobby. Sessions available to attend in-person will be indicated in the announcement information. In-person participants without NASA badges will need a valid visitor badge (US citizenship or permanent residency is required) to enter the facility.

Join Us Online

To attend an AMS seminar, click on the Microsoft Teams link in the seminar description. You can connect through the desktop Teams App if you have it, or you can select "Watch on the Web Instead" to enter the meeting as a guest. Please ensure that you've muted your microphone in Teams before you select "Join Now" to enter the meeting lobby.