Takeoff/landing Assessment of an Hsct with Pneumatic Lift Augmentation

Pneumatic technologies, such as Circulation Control airfoils, have been experimentally demonstrated to generate very high lift coefficients at low angles of attack. These blown airfoils offer great potential for advanced subsonic transports. Yet, the potential of this particular pneumatic technology is not limited to subsonic aircraft. In fact, Circulation Control has been chosen as an enabling technology to be applied on a generic High Speed Civil Transport (HSCT) under NASA Grant NAG-1-1517. Research on this contract was directed to a first-order quantitative estimate of the impact of Circulation Control on the takeoff and landing performance of an HSCT and is summarized in this paper. A reference point was established with an HSCT utilizing conventional high-lift devices that resulted in a takeoff field length of approximately 13,000 ft. The incremental changes in lift and drag established from the wind tunnel experiments performed in the above stated grant were then applied to this configuration and the low speed performance enhancements and degradations were quantified. The application of Circulation Control was shown to reduce the takeoff field length by as much as 31% from the reference point. This result strongly warrants further investigations with higher order analysis since the first order estimate shows significant improvements in low speed performance of an HSCT with Circulation Control pneumatic technology.