(Georgia Institute of Technology, 2021-01)
Ahuja, Jai; Mavris, Dimitri N.
The impacts of boundary layer ingestion (BLI) on vehicle performance can be modeled using either a decoupled or a coupled approach. Several studies in literature have adopted the former, while some have shown differences between the two approaches for the performance analysis and design refinement of a sized aircraft. This study quantifies the consequences of ignoring aero-propulsive coupling at the aircraft sizing stage of conceptual design. To do so, a parametric and coupled aero propulsive design methodology is used that leverages surrogate modeling to minimize the computational burden of CFD in generating estimates of the BLI performance impacts. The method is applied to the design and analysis of two BLI concepts with engine locations similar to that on the D8 and the NOVA-BLI.
(Georgia Institute of Technology, 2021-01)
Ahuja, Jai; Mavris, Dimitri N.
As part of an effort to develop a parametric and coupled aero-propulsive conceptual design methodology for boundary layer ingesting (BLI) aircraft, there is a need to investigate propulsor sizing and off-design impacts on the ingested boundary layer. This study uses 3D CFD analysis to quantify the BLI effects trends as a function of fan annulus area and mass flow rate required, for engine locations similar to those on the the D8, NOVA-BLI and the STARC-ABL concepts. This study extends previous work that relied on CFD analysis of an axisymmetric model for the STARC-ABL concept. The results from this study highlight the propulsor’s contribution to the aero-propulsive coupling inherent in BLI concepts.
(Georgia Institute of Technology, 2020-01)
Ahuja, Jai; Mavris, Dimitri N.
Conceptual design of boundary layer ingesting (BLI) aircraft requires a methodology that captures the aero-propulsive interactions in a parametric fashion. This entails modeling the impacts of BLI as a function of the airframe and propulsor design. Previous work has analyzed the sensitivity of these BLI effects to the propulsor size and throttle. This paper assesses the sensitivity of the BLI effects to the airframe design through a series of experiments, using CFD. The scope of this analysis is restricted to tube and wing type BLI concepts. Results from these studies help identify the critical airframe design space that needs to be considered when generating a parametric model of the BLI effects. Guidelines regarding the level of detail required for the airframe geometry model are discussed.