Improved Representation of High-Lift Devices for a Multidisciplinary Conceptual Aircraft Design Process

A methodology for improving the quality of high-lift-system performance prediction within a multidisciplinary conceptual design process is presented. The high-lift-system geometry is explicitly modeled and a multiple-lifting-line method is used to compute its aerodynamic characteristics. Computation times are acceptable for use in a conceptual design process. The results for several test cases show good agreement with wind-tunnel and/or high-fidelity numerical data. In addition, the method allows for further enhancement by using nonlinear airfoil polars for interpolation, improving drag prediction, and introducing some degree of nonlinear aerodynamic behavior. Nomenclature A = altitude A0 = numerical coefficient B0 = numerical coefficient CD = drag coefficient (3-D) CDi = induced drag coefficient (3-D) CD0 = zero-lift drag coefficient (3-D) Cd = section drag coefficient (2-D) CL = lift coefficient (3-D)