Application Of Laminar Flow Control To Supersonic Transport Configurations

The feasibility and impact of implementing a laminar flow control system on a supersonic transport configuration were investigated. A hybrid laminar flow control scheme consisting of suction controlled and natural laminar flow was developed for a double-delta type wing planform. The required suction flow rates were determined from boundary layer stability analyses using representative wing pressure distributions. A preliminary design of structural modifications needed to accommodate suction through a perforated titanium skin was carried out together with the ducting and systems needed to collect, compress and discharge the suction air. The benefits of reduced aerodynamic drag were weighed against the weight, volume and power requirement penalties of suction system installation in a mission performance and sizing program to assess the net benefits. The study showed a feasibility of achieving significant laminarization of the wing surface by use of a hybrid scheme, leading to an 8.2 percent reduction in the cruise drag. This resulted in an 8.5 percent reduction in the maximum takeoff weight and a 12 percent reduction in the fuel burn after the inclusion of the LFC system installation penalties. Several research needs were identified for a resolution of aerodynamics, structural and systems issues before these potential benefits could be realized in a practical system. Parikh, P. G. and Nagel, A. L. Unspecified Center AERODYNAMIC DRAG; BOUNDARY LAYER CONTROL; BOUNDARY LAYER STABILITY; LAMINAR BOUNDARY LAYER; PRESSURE DISTRIBUTION; SUPERSONIC TRANSPORTS; WING PLANFORMS; WINGS; AERODYNAMICS; DRAG REDUCTION; FLOW VELOCITY; LAMINAR FLOW; SUCTION; TAKEOFF; TITANIUM...

The viewgraphs and discussion of the potential benefits and technology development requirements of supersonic Hybrid Laminar Flow Control (HLFC) are reviewed. For the last three years, Boeing has performed studies on the application of laminar flow control to High Speed Civil Transport (HSCT) configurations. Large potential net benefits were identified for laminar flow control, even after accounting for the significant implementation penalties. However, the technical risks are high at this time, and an early, aggressive technology development program is required if laminar flow control (LFC) is to be incorporated in a year 2005 HSCT program. The benefits and required development effort are addressed. Of all the aerodynamic advances that are being considered for the HSCT, LFC has the largest potential for improving the supersonic lift drag ratio of a given configuration. The work accomplished to date, sponsored by NASA Langley, is summarized. This work includes studies on HLFC application to HSCT, cruise HLFC/low speed boundary layer control (BLC) compatibility, and impact of M 0.9 HLFC and high lift BLC. Requirements for production committments are listed. The need for a HSCT-HLFC Risk Reduction Program is addressed. Supersonic HLFC development planning and future applications are addressed. Laminar flow/high-lift integration is addressed. Neumann, Frank Unspecified Center ...

In High-Speed Dreams, Erik M. Conway constructs an insightful history that focuses primarily on the political and commercial factors responsible for the rise and fall of American supersonic transport research programs. Conway charts commercial supersonic research efforts through the changing relationships between international and domestic politicians, military/NASA contractors, private investors, and environmentalists. He documents post-World War II efforts at the National Advisory Committee on Aeronautics and the Defense Department to generate supersonic flight technologies, the attempts to commercialize these technologies by Britain and the United States during the 1950s and 1960s, environmental campaigns against SST technology in the 1970s, and subsequent attempts to revitalize supersonic technology at the end of the century. High-Speed Dreams is a sophisticated study of politics, economics, nationalism, and the global pursuit of progress. Historians, along with participants in current aerospace research programs, will gain valuable perspective on the interaction of politics and technology.

This book presents the challenges, the tools and the concepts for developing economically viable high speed civil transport aircraft under environmental constraints. Computational tools for aircraft design and optimization are outlined and application in an industrial environment is shown for new and innovative case studies.