Winglet design and analysis for low altitude solar powered UAV

Download
index.pdf
2016
Gölcük, Ali İhsan
Show full item record
304
views
933
downloads
To improve the aerodynamic performance of aircraft, comprehensive studies have been carried out in different areas such as wing optimization, tail types and fuselage shape, etc… One of the most important factors affecting the aerodynamic performance of the aircraft is lift induced drag caused by wingtip vortices. Winglet is a device referred as a small, vertical and angled extension attached at aircraft wingtip. It is used to minimize strength of vortices and reduce the lift induced drag. Various types of winglets have been designed and investigated to enhance aerodynamic performances of aircraft. This thesis describes winglet design and analysis performed on rectangular wing of MH 114 airfoil for TÜBİTAK Unmanned Air Vehicle (UAV). The aim of this study is designing elliptical winglet and performing Computational Fluid Dynamics (CFD) analysis for different winglet parameters. The main objective of this study is to compare aerodynamic characteristics of base wing and wing with winglet and investigate the performance of winglets shape in terms of different parameters such as cant angle, sweep angle, taper ratio, toe angle and twist angle. vi Winglet drawing is done in CATIA. In design algorithm, firstly, cant angle, sweep angle and taper ratio parameters are used in a triple combination with each other (27 models). Secondly, toe (6 models) and twist (6 models) parameters are applied to winglet separately which has the best L/D values in the first 27 models. Totally 39 different winglet models are investigated. The computational simulation was performed at low subsonic flow speed in ANSYS using finite volume approach. k-ω SST is used as a turbulence model. To compute the flow around the model, 3-D unstructured tetrahedral mesh is used. The aerodynamic characteristics of lift coefficient (CL), drag coefficient (CD) and lift to drag ratio (L/D) were compared for 39 different winglet models at cruise conditions and zero angle of attack (AOA). To investigate stall characteristic of clean wing and winglet (has best L/D ratio), they were compared at different AOA (-5° to 20°). Moreover, viscous and pressure effects of drag and lift force of clean and the best case configurations are compared and examined. A further point, at different velocities, clean wing and wing with winglet were analyzed in order to observe L/D change. Analysis showed that, elliptical winglet increased L/D value on the order of 8.32% compared to base wing. Hence, a significant improvement in aerodynamic performance is obtained for TİHAS.
Aerofoils., Flaps (Airplanes)., Airplanes, Micro air vehicles., Low altitude aeronautics., Computational fluid dynamics.
http://etd.lib.metu.edu.tr/upload/12619766/index.pdf
https://hdl.handle.net/11511/25458
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Winglet design and analysis for low-altitude solar-powered UAV
Gölcük, Ali Ihsan; Kurtuluş, Dilek Funda (2017-01-01)
One of the most important factors affecting the aerodynamic performance of the aircraft is lift-induced drag caused by wingtip vortices. This study describes the winglet design and analysis for solar-powered unmanned air vehicle (UAV). The motivation of this study is designing elliptical winglet to explore efficient shapes using multiple winglet parameters such as cant angle, sweep angle, taper ratio, toe angle and twist angle. The aim was to investigate the performance of parameters that constitute the win...
Control of flow structure on low swept delta wing using unsteady leading edge blowing
Çetin, Cenk; Yavuz, Mehmet Metin; Department of Mechanical Engineering (2016)
There is an increasing interest in recent years in the aerodynamics of low swept delta wings, which can be originated from simplified planforms of Unmanned Air Vehicles (UAV), Unmanned Combat Air Vehicles (UCAV) and Micro Air Vehicles (MAV). In order to determine and to extend the operational boundaries of these vehicles with particular interest in delaying stall, complex flow structure of low swept wings and its control needs to be understood. Among different flow control strategies, blowing through differ...
Development of unsteady models for flapping wings' controller design approach
Ormancı, Filiz; Kurtuluş, Dilek Funda; Arıkan, Kutluk Bilge; Department of Aerospace Engineering (2016)
Among a wide variety of micro air vehicles (MAV) due to their sizes, shapes, mechanisms and remoting technique; insect scaled flapping wing vehicles offer potential advantages like; higher agility for collision avoidance by rapid maneuvering compared to fixed wing MAVs, less noise compared to rotary wing MAVs, number of similar species in nature to imitate while modeling. Therefore, they are mainly in favor for defense applications. Main scope of the thesis is to develop an unsteady model capable of calcula...
Structural optimization of a composite wing
Sökmen, Özlem; Akgün, Mehmet A.; Department of Aerospace Engineering (2006)
In this study, the structural optimization of a cruise missile wing is accomplished for the aerodynamic loads for four different flight conditions. The flight conditions correspond to the corner points of the V-n diagram. The structural analysis and optimization is performed using the ANSYS finite element program. In order to construct the flight envelope and to find the pressure distribution in each flight condition, FASTRAN Computational Fluid Dynamics program is used. The structural optimization is perfo...
Parametric investigation of hull shaped fuselage for amphibious UAV
Sazak, Emre; Kurtuluş, Dilek Funda; Department of Aerospace Engineering (2017)
Performance of amphibious unmanned aerial vehicles (UAV’s) that take off from and land on water, like seaplanes, greatly depend on hydrodynamic effects as well as aerodynamic effects, therefore their geometries need to be optimized for both. This study mainly investigates the effect of geometric parameters of a generic, hull-shaped fuselage that are constrained by hydrodynamic drivers, such as the step height needed to reduce hydrodynamic drag, sternpost angle and deadrise angle needed for safe landing; on ...
Citation Formats
A. İ. Gölcük, “Winglet design and analysis for low altitude solar powered UAV,” M.S. - Master of Science, Middle East Technical University, 2016.
METU IIS - Integrated Information Service open@metu.edu.tr