Application of laminar flow control to large subsonic military transport airplanes

Abstract

Abstract : A Preliminary Design study has been made to investigate the impact of the application of laminar flow control on the performance, weight, fuel consumption, and economics of a large transport airplane designed to carry a heavy payload (350,000 lb) for a long range (10,000 nmi). The study was conducted in three phases. In the first phase, conceptual design investigations were conducted to identify the features of an LFC airplane optimized to accomplish the mission objectives. A reference turbulent airplane also was developed in this phase. Design and analysis studies were made to develop the final LFC configuration. This configuration was sized to determine the gross weight, engine size, wing area, and fuel requirements necessary to achieve the design mission. Various performance trade and sensitivity studies were conducted for the turbulent and LFC airplanes in the third phase. Life-cycle and operating cost evaluations were also made. A valid assessment of an LFC airplane must be preceded by an extensive design, development, and flight test program. Consequently, this study focused on identifying the relative benefits from applying LFC, and on the sensitivites of these relative benefits to the current major LFC uncertainty items.