Sensitivity analysis of geometric parameters on the aerodynamic performance of a multi-element airfoil

Abstract

High-lift devices play a vital role in most commercial airplanes' design, maintenance, safety, and performance. The design of high-lift devices is complex due to the flow physics, actuation systems, geometry, and system support. Especially in a three-element high lift system, the position of the slat and flap significantly affects the aerodynamic performance. In this study, the sensitivity of aerodynamic quantities of the three-element airfoil to four geometric parameters was investigated using computational methods. In the sensitivity analysis, the Sobol sequence sampling method, the radial basis function, and Sobol's method were used to generate the sampling points in the given design space, to construct the metamodel, and evaluate the sensitivity indices, respectively. The sensitivity indices show that the slat overhang position is the largest contributor to the first-order and total effects. In general, it was shown that the forward elements play an important role in changing the flow behaviour of the trailing elements. Further, it was noted that the flap gap has the largest interaction effects on the lift and drag of the overall airfoil.