Computational Fluid Dynamics Analysis of Externally Blown Flap Configuration for Transport Aircraft

Abstract

As aircraft grow in size to meet the ever-increasing demand from the international traveling public, the limits imposed by current airport facilities become apparent. Continual growth of environmental awareness within the community and noise reduction requirements, combined with the issue of long takeoff and landing runs required by
the large jet transport aircraft, create problems for engineers. The implementation of externally blown flaps would allow for steeper approach paths pertaining to a reduction in noise pollution and reduce the takeoff and landing distance required. The reduction in the distance required for aircraft operations will allow for an increase in the size
of aircraft or operations from fields that were previously unavailable. The introduction of externally blown flaps has occurred on a production aircraft, the C-17 Globemaster III, in use with the United States Air Force. The advantages provided by the system are obvious, improving the aircraft’s takeoff and landing performance dramatically. This
study focuses on a computational fluid dynamics analysis of the three-dimensional flow characteristics of the externally blown flaps configuration for transport aircraft and future unmanned aerial vehicles operating in remote areas. The study compares two- and three-dimensional analysis with and without externally blown flaps, increasing
understanding of the vital elements of the system so as to allow the possibility of further implementation of externally blown flaps in improving the airline industry in regard to airway congestion.