Date

2017

Author

Şenipek, Murat

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In this thesis, comprehensive software is developed to predict the performance of generic air vehicles. The word “generic” stands for the variety of the air vehicles that this Generic Air Vehicle Model (GAVM) encloses. GAVM software includes multiple disciplines such as flight dynamics, aerodynamics, propulsion, rotational dynamics, flight stability and control, numerical multi-variable optimization and object oriented programming. Helicopters, airplanes, compound helicopters, multi-rotor and tilting rotor vehicles can be designed, analyzed and simulated. In order to achieve this ability of modeling each aerodynamic component of a given air vehicle must be mathematically modeled in a generic manner. Therefore, object oriented programming principles are implemented while developing the code such that each modeled component can be populated and used wherever necessary. GAVM software is written in C++ programming language and is used both as a standalone application and shared library. After modeling an air vehicle there are different types of analysis options. Trim analysis, dynamic flight simulation, point performance predictions are available. Beyond the inherently available analysis options, GAVM can be used by an external application as a plant model for an air vehicle. Therefore, wide-variety of studies is possible to conduct such as control system design, flight simulation, and design optimization. The fidelity and complexity of the mathematical models of the components are compromised such that the balance between the computational time cost and analysis requirements is sustained. Shared library version of the code provides the ability to simulate the flight of different air vehicles in same environment which enables the designer to handle swarm-like problems for different air vehicles. In the first chapter, introductory information is provided about the problem and current requirements of aerospace designs and analyses. Next chapter consists of implemented mathematical theories behind the modeled components in detail. Each component and each sub-model is prescribed and relations between the modeled objects are outlined. Trim point optimization algorithm which uses mainly the classical Newton’s optimization theory is explained. Moreover, implemented Engine model to simulate the available power and consumed energy to see the limits of the designed vehicle and conduct the point performance calculations is explained. Concepts related to software design are also mentioned in that chapter and brief information is provided about the algorithm. Next chapter includes a flight simulation example of a quad-rotor which is modeled via GAVM and abilities of the software are depicted. Throughout the next two chapters, micro-scale and macro-scale validation cases are implemented and results are compared with the available test data. Each sub-component is validated in the first chapter and conventional helicopter; airplane, tilting-rotor and quad-rotor configurations are analyzed and compared with the flight test data. Results show consistency and each modeled component is validated with the available aerodynamic data successfully. Last chapter includes the conclusion and appendix provides input/output sample files. To sum up, this work includes detailed multi-disciplinary analysis software for air vehicles and brings the ability to accelerate and facilitate the design and analysis of aerial vehicles and new concepts. 

Subject Keywords

Airplanes., Helicopters., Aerodynamics., Rotors (Helicopters).

URI

http://etd.lib.metu.edu.tr/upload/12621541/index.pdf
https://hdl.handle.net/11511/26774

Collections

Graduate School of Natural and Applied Sciences, Thesis