HLFC-optimized retrofit aircraft design of a medium-range reference configuration within the AVACON project

Abstract

AbstractThis paper presents an approach for the design of a retrofit aircraft with integrated, optimized hybrid laminar flow control (HLFC). The basis for this research is a medium-range reference configuration derived within the German LuFo project “Advanced Aircraft Concepts” (AVACON). For the aerodynamics, an in-house-developed process chain for flow analysis is used, which requires airfoil shapes at specific sections of a known wing geometry. To improve the accuracy, pressure distributions from the 2D flow solver MSES are first aligned to high-fidelity 3D results from DLR’s TAU code for extracted airfoils. This is done by varying parameters of the transformation methods used. Subsequently, the required suction distributions are optimized based on pre-defined criteria; these include not only the aerodynamic effects but also the needed mass flows. After optimizing the HLFC system architecture concerning mass and power offtakes, a retrofit aircraft is designed with the in-house “Multidisciplinary Integrated Aircraft Design and Optimization” (MICADO) environment. Compared to the turbulent baseline, the promising potential of the HLFC technology is demonstrated. In addition, the actual benefit of the optimization approach is evaluated in the context of overall preliminary aircraft design. This is done by redesigning the aircraft with other suction distributions and HLFC system architectures. Although it is shown that the approach leads to an overall optimum, the optimization benefit remains small. This indicates the limits of the HLFC technology as a pure add-on for initially turbulent aircraft and the need for the application of new laminar wing design methods to tap the full potential of HLFC.