Analysis of the aerodynamic off-design characteristics of the multidiscipline optimized M=1.6 CISAP configuration

Abstract

The analysis of the optimized supersonic configurations at supersonic off-design, at transonic as well as low-speed conditions shows: The alternate supersonic load case found to be more realistic by other partners in this work package generates higher aerodynamic loads. Although the flow needs to produce higher lift coefficients no significant flow separations are found. Therefore such flows can still be predicted using inviscid method keeping the numerical effort within the MDO process low. The lower fidelity aerodynamic performance estimations implemented in the MDO process for transonic cruise is found to slightly under predict the configurations performance estimated by viscous methods. Meeting the aerodynamic low-speed performance estimated by the lower fidelity model in the MDO process is found to be quite adequate for the approach flight phase. During climb out the stated performance values are viewed as very challenging and the empirical model is assessed as too optimistic for the analysed configuration. This holds even if the low-speed performance of the implemented high-lift system could be increased mainly by increasing the leading edge flap size.