Conceptual Design of Boundary-Layer-Ingesting Aircraft Capturing Aeropropulsive Coupling

Abstract

The impacts of boundary-layer ingestion on aircraft performance can be modeled using either a decoupled or a coupled approach. Several studies in literature have adopted the former, whereas 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 aeropropulsive coupling at the aircraft sizing stage of conceptual design. To do so, a parametric and coupled aeropropulsive design methodology is used that leverages surrogate modeling to minimize the expense of computational fluid dynamics in generating estimates of the boundary-layer ingestion performance impacts. The method is applied to the design and analysis of two aircraft in the 150 passenger class, with different engine locations. Discrepancies in block fuel burn estimates, as large as 2.15%, were found to occur by ignoring aeropropulsive interactions.