Prediction of drag force on gimbal system via balance technique and wake integration method

Download
2014
Yeşilyurt, Emrah
This thesis study examines the drag force exerted on a mini gimbal system through two methods of drag prediction. Wind tunnel experiments are performed with the real gimbal model since it is small enough. Drag force is measured by the balance technique using a load-cell, consisting of a metal beam and strain gauges adhered to it, which is designed and produced. For various Reynolds numbers drag force exerted on the model is measured. Results are essential since there is a restricted literature about it due to its military feature. Also drag force is estimated for various Reynolds numbers by wake integration method which is based on the conservation of linear momentum over a control volume and related measurements in the wind tunnel. Results obtained by two methods are compared and discussed for optimum selection of the control volume for the second method used. Furthermore, flow over the gimbal is examined and some flow visuals are obtained in a qualitative manner.

Suggestions

Computational fluid dynamics modelling of store separation using grid method
Demir, Görkem; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2017)
In this study, two different wind tunnel techniques, captive trajectory and the grid surveying method, were implemented to computational fluid dynamics (CFD) and used to calculate the trajectory of a store. The main purpose of this thesis is to demonsrate that grid method is an alternative method to those already used as it provides flexibility to store separation problems and can be used during the design process. EGLIN test geometry was used to validate the analyses results because it provided existing wi...
Experimental investigation of the effects of tip injection on the characteristics of the tip vortex on a model wind turbine
Anık, Ezgi; Uzol, Oğuz; Department of Aerospace Engineering (2015)
This study presents the results of an experimental study performed on a horizontal axis wind turbine to investigate the effects of spanwise steady tip injection on the tip flow characteristics of a model turbine. Experiments are performed in front of an open-jet wind tunnel facility on a specially designed model wind turbine that has a 3-bladed rotor with NREL S826 airfoil profile. The turbine has a specially designed injection system which consists of a pressure chamber, a hollow shaft, pressurized hub and...
Computational fluid dynamics simulations of ship airwake with a hovering helicopter rotor
Orbay, Ezgi; Uzol, Oğuz; Sezer Uzol, Nilay; Department of Aerospace Engineering (2016)
In this thesis, Computational Fluid Dynamic simulations of ship airwake for a simple ship geometry are performed for the horizontal and inclined deck configurations and also with and without the helicopter rotor over the deck. An actuator disk model is used for the CFD simulations of a rotor model hovering over the flight deck. All of the computations are performed by using a commercial finite volume CFD flow solver. The unstructured tetrahedral grids are generated in the computational domain including ship...
Improving flow structure and natural convection within fin spacings of plate fin heat sinks
Özet, Mehmet Erdem; Tarı, İlker; Department of Mechanical Engineering (2015)
The main objectives of this thesis are to numerically investigate the previously observed recirculation zones and longitudinal vortices that occur in low fin height plate finned horizontal heat sinks and to improve the flow structures and heat transfer in these zones using various approaches with the help of simulations performed using commercially available CFD software. The approaches used for improvements are replacing the outer most fins with higher ones, introducing gaps on the length of the fins in va...
Design of a traverse system for the characterization of a large-scale wind tunnel
Ulu, Tunahan; Perçin, Mustafa; Department of Aerospace Engineering (2022-9)
This study presents the design and simulations of a traverse system and preliminary characterization measurements of the RÜZGEM large-scale wind tunnel. In the first phase of the study, the traverse system was simulated aerodynamically using computational fluid dynamics (CFD) tools. The effects of the rectangular, whole profile and partial profile traverse mechanisms on the measurements were examined. The probe lengths were studied in detail to determine the most suitable length. According to the simulation...
Citation Formats
E. Yeşilyurt, “Prediction of drag force on gimbal system via balance technique and wake integration method,” M.S. - Master of Science, Middle East Technical University, 2014.