Development of an advanced composite external fuel tank for air platforms

Karahan, Uğurcan
This thesis provides a design approach for an external fuel tank, which permits external mounting to the air platforms including rotorcrafts and aircrafts. The development stages include both a computational and an experimental study. In this thesis, unique combination of advanced composite material solutions is investigated in the structural design process. Filament-wound tank structure is modeled as multi-layered orthotropic structure. Various worst-case loading scenarios defined by internationally recognized design standards and regulations are performed by utilizing a software platform based on Finite Element Method (FEM). Results obtained by means of FEM are examined in order to determine a proper winding angle and to verify the performance of the structure exposed to combined static and transient loadings in the operating environment of the structure. The insight gained by means of such analyses allows examining every structural aspect of the tank structure. The failure prediction is performed according to the Reserve Factor index calculated for Tsai-Wu Failure Theory. The dynamic response of the structure during a crash is determined with a full-scaled prototype of the External Fuel Tank. The most severe conditions that the tank would experience when deployed within the entire operational envelope are simulated at the first non-destructive sled test facility of Turkey which is the Vehicle Safety Facility of METU-BILTIR. The result of the simulation indicates that the survival of the tank structure is ensured during severe crash impact conditions. Finally, this study has resulted in obtaining an External Fuel Tank, which maintains its structural integrity for all loading conditions, while meeting the weight target.


Development of an autopilot for automatic landing of an unmanned aerial vehicle
Arıbal, Seçkin; Leblebicioğlu, Mehmet Kemal; Department of Electrical and Electronics Engineering (2011)
This thesis presents the design of an autopilot and guidance system for an unmanned aerial vehicle. Classical (PID) and modern control (LQT, Sliding Mode) methods for autonomous navigation and landing in adverse weather conditions are implemented. Two different guidance systems are designed in order to navigate through waypoints during normal and/or emergency flight. The nonlinear Pioneer UAV model is used in controller development and simulations. Aircraft is linearized at different trim points and total a...
Experimental and numerical inestigation of an s-duct diffuser designed for a micro turbojet engine powered aircraft
Aslan, Samet; Kurtuluş, Dilek Funda; Department of Aerospace Engineering (2016)
S-duct diffusers are often used for aircraft propulsion systems that convey the intake air to the engine compressor. In this thesis, flow structure at separated entrance conditions in an S-duct diffuser that designed for a micro turbojet engine powered aircraft is investigated using experimental and numerical methods. Flow characteristics such as flow separation, secondary flows, and swirl are investigated to find out the source of distortions and pressure loss at aerodynamics interface plane. Experiments a...
Design and manufacturing of a high speed, jet powered target drone
Özyetiş, Ender; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2013)
This thesis presents the design and manufacturing of a high speed jet powered UAV which is capable of flying at M=0.5. Flight time of the UAV is 30 minutes at 1700 m above sea level. Aerodynamic and structural design of the UAV is conducted for 6g sustained and 9g instantaneous loads. Low aspect ratio blended wing-body design is decided due to low drag and high maneuverability. The Structure of the UAV consists of the composite parts such as frames and skin and mechanical parts such as landing gears which a...
Optimization of types, numbers and locations of sensors and actuators used in modal analysis of aircraft structures using genetic algorithm
Pedramasl, Nima; Şahin, Melin; Acar, Erdem; Department of Aerospace Engineering (2017)
Aircraft structures are exposed to dynamic loads under service conditions and therefore, it is necessary to determine their dynamic characteristics. Dynamic characteristics of a structure can be determined using simulation-based methods such as finite element analysis (FEA) or test-based methods such as experimental modal analysis (EMA). In order to perform an EMA with reliable and high quality results, test equipment must be lightweight and have high accuracy. In addition, the sensors and actuators must be...
Design and manufacturing of a solar powered unmanned air vehicle
Özcan, Servet Güçlü; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2015)
The aim of this thesis is to describe the conceptual design, performance analysis including solar energy collection and manufacturing process of a solar powered unmanned aerial vehicle (UAV) and validate the design through ground and flight tests. Through a literature survey of solar powered aircraft, main design requirements are chosen. The solar powered UAV designed for this study is a small scale aircraft and intended to be used simply and frequently by end-users. Therefore it is designed as a flying win...
Citation Formats
U. Karahan, “Development of an advanced composite external fuel tank for air platforms,” M.S. - Master of Science, Middle East Technical University, 2014.