Aerospace & Mechanical
Engineering

Seminar Announcement

Aircraft Propulsor Modeling and Design for Boundary Layer Ingestion

David K. Hall

Postdoctoral Fellow

MIT Gas Turbine Laboratory
Massachusetts Institute of Technology
Cambridge, MA

Propulsion with Boundary Layer Ingestion (BLI), where a craft's boundary layer or wake fluid is ingested and re-accelerated by the propulsor, has long been recognized to provide a theoretical propulsive efficiency benefit. A major challenge associated with aircraft BLI is non-uniform flow at the engine inlet, which can lead to decreased engine efficiency, decreased engine stall margin, and increased unsteady force on rotating turbomachinery. This presentation describes a new conceptual framework for three-dimensional turbomachinery flow analysis and its use to assess fan stage attributes for mitigating the adverse effects of BLI. The turbomachinery is modeled in CFD calculations using momentum and energy source distributions that are determined as a function of local flow conditions and an approximate blade geometry. Comparison with higher-fidelity computational and experimental results shows the analysis captures the principal flow redistribution and distortion transfer effects associated with BLI fans, which differ from established models for compressor distortion response. The distortion response is assessed for a range of fan stage design parameters, and the results indicate that circumferential variations in the design of the downstream fan exit guide vanes yield the greatest reductions in flow non-uniformities in the rotor, and may offer the most potential for improved performance with BLI inlet distortion.


David K. Hall received his Bachelor of Science in Engineering from Duke University, where he majored in Mechanical Engineering and Mathematics, and his SM and PhD in Aeronautics and Astronautics from MIT, where his thesis work was associated with development and assessment of the D8 advanced aircraft concept under the NASA N+3 program. His research interests include aircraft propulsion, gas turbines, engine-aircraft integration, aerodynamics, aeromechanics, and design of turbomachinery, and computational modeling for fluid dynamics. In 2015, he taught at the Singapore University of Technology and Design as a postdoctoral fellow, and he is now continuing his fellowship at the MIT Gas Turbine Laboratory, with research on advanced propulsion concepts for efficient air transportation.

Wednesday, January 11, 2017
3:30 PM
Seaver Science Library, Room 150 (SSL 150)

Refreshments will be served at 3:15 pm.