Aerodynamic investigation of a model scale helicopter rotor in ground effect

Download
2017
Şahbaz, Mehmet
In this thesis, ground effect issue which is a vital topic for helicopter industry is investigated with model scale.For this purpose, a test setup with model helicopter rotor is established. With setup, ground effect is investigated with inclined ground and ground without inclination. Thrust and torque values are obtained for different rotation speeds with constant collective pitch. Comparison with literature is done and reliability of the test setup is proven. Inclined Ground Effect and Ground Effect with extreme proximity scenarios are tested. The proper trends of the performance parameters in these scenarios are obtained. For the sake of performance parameter alterations, CFD (Computational Fluid Dynamics) Method is applied to analyze the rotor downwash. To model the rotating helicopter blade, Single Moving Reference Frame Method (SMRF) is used. In this method, the blade and background mesh are kept still and rotational velocity is defined at each cell in the domain. With CFD results, flow physics is studied and performance changes in ground effect are explained.

Suggestions

Flow characterization of full, partial, and inclined ground effect
Koçak, Göktuğ; Yavuz, Mehmet Metin; Nalbantoğlu, Volkan; Department of Mechanical Engineering (2016)
Flight condition of helicopters proximity to the ground, so-called “Ground Effect”, is among one of the most recent research areas since the aerodynamic performance of these vehicles significantly vary due to the flow dynamics associated with the interaction between the rotor and the surface. Thus, a comprehensive understanding of the rotor wake during in and out of ground effect is needed to improve the flight performance. Helicopters operate in ground effect in many different ways including full ground, p...
Aerodynamic modeling and parameter estimation of a quadrotor helicopter
Kaya, Derya; Kutay, Ali Türker (2014-01-01)
This study focuses on aerodynamic modeling of a quadrotor helicopter and the estimation of the model parameters in wind tunnel tests for hover, vertical climb, and forward flight conditions. The motion of a quadrotor is mainly affected by the aerodynamic forces and moments generated by rotors. Accurate calculation of rotor loads is essential for high fidelity simulation of a quadrotor. Momentum and blade element theories are used to obtain expressions for rotor forces and moments for a traveling vehicle. Th...
Experimental Investigation of Aerodynamics of Flapping-Wing Micro-Air-Vehicle by Force and Flow-Field Measurements
Deng, Shuanghou; Perçin, Mustafa; van Oudheusden, Bas (2016-02-01)
This study explores the aerodynamic characteristics of a flapping-wing micro aerial vehicle (MAV) in hovering configuration by means of force and flowfield measurements. The effects of flapping frequency and wing geometry on force generation were examined using a miniature six-component force sensor. Additional high-speed imaging allowed identification of the notable different deformation characteristics of the flexible wings under vacuum condition in comparison to their behavior in air, illustrating the re...
Development of a comprehensive and modular modelling, analysis and simulation tool for helicopters
Yücekayalı, Arda; Kutay, Ali Türker; Department of Aerospace Engineering (2011)
Helicopter flight dynamic, rotor aerodynamic and dynamic analyses activities have been a great dispute since the first helicopters, at both design and test stages. Predicting rotor aerodynamic and dynamic characteristics, helicopter dynamic behavior and trimmed flight conditions is a huge challenge to engineers as it involves the tradeoff between accuracy, fidelity, complexity and computational cost. Flight dynamic activities such as; predicting trim conditions, helicopter dynamic behavior and simulation of...
Genetic Algorithm based aerodynamic shape optimization tool for wind turbine blades and its implementation to helicopter blades
Polat, Özge; Sezer-uzol, Nilay; Tuncer, İsmail Hakkı (2014-01-01)
This study presents a methodology first built up for the aerodynamic shape optimization for wind turbine rotors and its modified version for a helicopter rotor in hover. The Genetic Algorithm (GA) coupled with an in-house Blade Element Momentum (BEM) tool is used in the design optimization process. The wind turbine blade optimization studies are performed for maximizing the power production at a given wind speed, rotor speed and rotor diameter, while for the helicopter blade optimization in hover, figure of...
Citation Formats
M. Şahbaz, “Aerodynamic investigation of a model scale helicopter rotor in ground effect,” M.S. - Master of Science, Middle East Technical University, 2017.