Tomas Melin

Morphing Winglets for Aircraft Multi-phase Improvement

The technology paradigm presented in this paper is to provide active control of winglet structure subject to external stimuli to meet operational performance criteria, by means of smart actuation integration. A tier schedule is employed to develop application to take full advantage of material compliance through MDO to form functionally active integrated non-planar wing, to improve multi-phase mission performance, manoeuvrability and integrated economics (e.g., 5-6% augmented aerodynamic eciency throughout the flight envelope, compared to 3% of current fixed winglets). This paper presents the first steps of the hierarchical methodology (i.e., smart actuation ecient down-selection) towards the final morphing application (i.e., MORPHLET), through the technology selection and preliminary optimized non-planar wing schedules.

Induced-Drag Compressibility Correction for Three-Dimensional Vortex-Lattice Methods

CD = drag coefficient CDi = induced-drag coefficient CD0 = zero-lift drag coefficient CL = lift coefficient CL ;c = compressible lift slope, 1= deg CL ;i = incompressible lift slope, 1= deg CP = pressure coefficient CP0 = incompressible pressure coefficient F = force, N k = induced-drag factor L = vortex segment direction vector M = Mach number Veff = effective velocity at vortex core, m=s Vrot = velocity induced by rigid-body rotations, m=s V = velocity induced by vorticity, m=s V c = velocity induced by compressible vorticity, m=s V1 = freestream velocity, m=s w = aerodynamic influence matrix = vortex strength, m=s = aspect ratio

Subscale flight testing used in conceptual design

Purpose - The purpose of this paper is to present the latest subscale demonstrator aircraft developed at Linkoping University. It has been built as part of a study initiated by the Swedish Material ...

Knowledge-based Integrated Wing Automation and Optimization for Conceptual Design

Contemporary aircraft design and development incurs high costs and consumes a lot of time for research and implementation. To minimize the development cost, an improvement of the conceptual design phase is desirable. A framework to support the initial design space exploration and conceptual design phase is presently being developed at Linkoping University. In the aircraft design, the geometry carries a critical, discriminating role since it stores a significant part of the information and the data needed for most investigations. Methodology for design automation of a wing with a detailed description such that the geometry is effectively propagated for further analysis is presented in this paper. Initial weight estimation of the wing is performed by combining the weight penalty method with a sophisticated CAD model. This wing model is used for airfoil shape optimization and later for structural optimization. A methodology for automatic meshing of the geometry for CFD and FEM when the surfaces increase or decrease during the design automation is proposed. The framework combining automation capability with shape and structural optimization will enhance the early design phases of aircraft conceptual design.

Wing profile performance variations influenced by manufacturing tolerances.

The sensitivity of wing profile performance metrics as a function of manufacturing tolerances and operational environment influence was studied using a numerical simulation. By employing a Monte-Carlo approach of varying the geometrical properties of a set of wing profiles, the sensitivity and statistical response was found, which in turn gives an indication towards both the most critical geometrical features and to which airfoil is the most robust with respect to constructions errors and operational fouling.

Design and Flight Testing of a Solar Powered Aircraft, a Student Challenge.

The presented work considers designing, building and flight testing a solar poweraircraft as a student project. The goal is to allow student to participate in an aircraft projectfrom design to flight test in order to acquire aircraft design knowledge from theoretical andpractical means. A first theoretical part consists of creating a sizing program for studyingdifferent concepts. Then the gathered knowledge will result in the realization of a flyingdemonstrator. This was realized during a student project over a 5 month period

Multidisciplinary Optimization of Wing Structure Using Parametric Models

Aircraft design is an inherently multidisciplinary activity that requires integrating different models and tools to reach a well-balanced and optimized product. At Linkoping University a design framework is being developed to support the initial design space exploration and the conceptual design phase. Main characteristics of the framework are its flexible database in XML format, together with close integration of automated CAD and other tools, which allows the developed geometry to be directly used in the subsequent preliminary design phase. In particular, the aim of the proposed work is to test the framework by designing, optimizing and studying a transport aircraft wing with respect to aerodynamic, geometry, structural and accessability constraints. The project will provide an initial assessment of the capability of the framework, both in terms of processing speed and accuracy of the results.