Aero-propulsive performance analysis of fuselage for boundary layer ingestion

Abstract

Aircraft fuel efficiency, noise, and emissions are some of the most important aspects being addressed in the research of novel aircraft configurations for meeting the future requirements of the aviation industry. One concept which has the potential for improving the aircraft fuel efficiency is called the boundary layer ingestion (BLI). Modification of the boundary layer flow using a power supply for favorable aerodynamic and/or propulsive effect, in general, could be called boundary layer ingestion. This method is especially possible when a propulsor is tightly integrated with the airframe which allows the partial recovery of power which is otherwise lost in the wake flows. A tube-wing aircraft fuselage with a boundary layer ingesting propulsor in the aft is a good candidate for the study as the fuselage is the body with the highest length in the streamwise direction resulting in a large potential for power recovery.
The present work involves the numerical assessment of the aero-propulsive performance of tube-wing aircraft fuselage with a boundary layer ingesting propulsor in the aft. This consists of the use of computational fluid dynamics with power balance and exergy analysis methods to analyze the various aspects of the flow in BLI configurations. The study focuses importantly on the design space exploration for analyzing the effect of axisymmetric fuselage geometry and flight conditions on propulsor (modeled as an actuator volume) power consumption. The effect of aircraft wings, propulsor blades, propulsor nacelle, and empennage are not included in the present study. The results are driven more towards understanding the effect of fuselage design on BLI, especially in transonic flights. The exploration is followed by constrained design optimization of axisymmetric fuselage geometry for obtaining least fuel burn.