Papers by Omer Kemal Kinaci
Journal of Offshore Mechanics and Arctic Engineering, 2016
The prediction of resistance of ships and submerged bodies is an important aspect in naval archit... more The prediction of resistance of ships and submerged bodies is an important aspect in naval architecture.
Journal of Marine Science and Application, 2016
International Journal of Naval Architecture and Ocean Engineering, 2015
ting the iterative procedure and is adapted to generate results. Effects of free surface and cavi... more ting the iterative procedure and is adapted to generate results. Effects of free surface and cavitation are ignored. It is believed that the present work will provide insight into the parametric interference between hydrofoils inside the fluid.
Volume 2: CFD and VIV, 2015
A direct and an iterative boundary element method using source distributions to represent the bod... more A direct and an iterative boundary element method using source distributions to represent the body are applied to calculate the pressure distribution on symmetric NACA airfoils. First, the effects of the foils on each other are examined. Then, the two methods are compared in terms of the solutions they generate and the time consumed. The calculations are made for different distances, panels and airfoil thicknesses to fully understand the basics of the interaction and the applicability of the iterative method.
ZET Su altında seyreden yapıların veya hidrodinamik destek sağlayan takıntıların serbest su yüzey... more ZET Su altında seyreden yapıların veya hidrodinamik destek sağlayan takıntıların serbest su yüzeyinde oluşturduğu dalga profili ve serbest su yüzeyinin hidrofoil üzerindeki kaldırma kuvveti katsayısına etkileri son yıllarda sıkça araştırma konusu olmuştur. Bu çalışmada çeşitli derinliklerdeki hidrofoilin etrafındaki akış sayısal olarak incelenmiştir. Bu amaç doğrultusunda sonlu hacimler metodu kullanılmıştır. Analizler için 5 derece hücum açısında NACA 0012 hidrofoili kullanılmış ve hidrofoil etrafındaki akış potansiyel kabul edilmiştir. Serbest su yüzeyini modellemek için Volume of Fluid (VOF) yöntemi kullanılmıştır. Froude sayıları 1,1.5,2,2.5 ve 3 olarak belirlenen hidrofiller üzerinde çalışılmış, derinlik oranı h/c ise 0.25 ile 15 arasında değiştirilmiştir. Anahtar Kelimeler: Potansiyel akış, HAD, VOF metodu, serbest su yüzeyi
The aim of this study is to mathematically model Bodrum type gulet vessels' series, starting ... more The aim of this study is to mathematically model Bodrum type gulet vessels' series, starting from a working vessel with a good performance in all aspects of seakeeping. Considering the fact that only one vessel is insufficient in building up a series form, some other similar (to main vessel) vessels weregenerated with One Minus Prismatic Coefficient distortion method. Some offsets were acquired and these offsets were nondimensionalized to graph nondimensionsl offset vs. prismatic coefficient values. Acquired equations were found by some numerous numerical Analysis methods and these equations were used to compose each station of the vessel. Curves included in the aft, fore, sheer and keel parts of the vessel were generated similar to that of the main vessel. AS a part of these study, a program that creates the hull of the gullet in accodance to the desired main dimensions is developed. From this program, a vessel having the same dimensions with the main vessel was generated and t...
In this paper, an iterative boundary element method (IBEM) was proposed to solve for a wing-in-gr... more In this paper, an iterative boundary element method (IBEM) was proposed to solve for a wing-in-ground
(WIG) effect. IBEM is a fast and accurate method used in many different fields of engineering and in this work; it is
applied to a fluid flow problem assessing a wing in ground proximity. The theory and the developed code are validated
first with other methods and the obtained results with the proposed method are found to be encouraging. Then, time
consumptions of the direct and iterative methods were contrasted to evaluate the efficiency of IBEM. It is found out that
IBEM dominates direct BEM in terms of time consumption in all trials. The iterative method seems very useful for quick
assessment of a wing in ground proximity condition. After all, a NACA6409 wing section in ground vicinity is solved
with IBEM to evaluate the WIG effect.
WIG vehicles have gained ground in the last decade due to bureaucratic and technological barriers... more WIG vehicles have gained ground in the last decade due to bureaucratic and technological barriers lifted thanks to the developments in the control engineering. These crafts can offer an economical transportation over the sea with their natural ability to use air like a cushion but there is still some enhancement to be made in terms of their efficiency. This paper deals with an efficiency augmenting method and proposes a twisted wing in ground proximity to improve lift-drag ratio. The analyses executed via CFD look promising to enhance the efficiency of these crafts’ wings.
International Journal of Ocean System Engineering
Blasius equation describes the boundary layer formed over a flat plate inside a fluid and this eq... more Blasius equation describes the boundary layer formed over a flat plate inside a fluid and this equation is solvednumerically by the method of moments which is a type of weighted residual methods. Compared to the tradition-ally used Runge - Kutta Method, Method of Moments propose a direct solution to Blasius Equation which makesit easier to solve. The obtained solutions show good agreement with the results found in literature and this studyaims to demonstrate the power of the method.
International Journal of Ocean System Engineering
The propeller performance has been investigated using a benchmark Duisburg Test Case ship with RA... more The propeller performance has been investigated using a benchmark Duisburg Test Case ship with RANSE. First, the hydrodynamic characteristics of propeller in case of open water have been analyzed by a commercial CFD program and the results are compared with those of experimental data. Later, the flow around the bare hull has been solved and the frictional resistance value and form factor of the ship have been obtained and compared with those of ITTC57 formulation and experimental results for validation. The free surface effect has been ignored. A good agreement has been obtained between the results of RANSE and experiments at both stages. Then the ship - propeller interaction problem was solved by RANSE and the differences in thrust, torque and efficiency of propeller as compared with the open–water numerical results have been discussed.
Tandem hydrofoil system is used even in the most ordinary ships; the hydrofoil that confronts the... more Tandem hydrofoil system is used even in the most ordinary ships; the hydrofoil that confronts the flow first represents the ship section, while the other hydrofoil stands for the rudder section. This study covers a parametric study on tandem hydrofoil interaction including variations of distance, thickness, angle of attack and chord length of hydrofoils. Circulation values of each hydrofoil are investigated to examine the strength of the interaction. 2-D iterative boundary element method is used with potential theory and the graphs of distance, thickness, angle of attack and chord length versus circulation are obtained. The implied aim is to maintain the optimum parameters for maximum lift and ship maneuverability.
A direct and an iterative boundary element method using source distributions to represent the bod... more A direct and an iterative boundary element method using source distributions to represent the body are applied to calculate the pressure distribution on symmetric NACA airfoils. First, the effects of the foils on each other are examined. Then, the two methods are compared in terms of the solutions they generate and the time consumed. The calculations are made for different distances, panels and airfoil thicknesses to fully understand the basics of the interaction and the applicability of the iterative method.
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Papers by Omer Kemal Kinaci
(WIG) effect. IBEM is a fast and accurate method used in many different fields of engineering and in this work; it is
applied to a fluid flow problem assessing a wing in ground proximity. The theory and the developed code are validated
first with other methods and the obtained results with the proposed method are found to be encouraging. Then, time
consumptions of the direct and iterative methods were contrasted to evaluate the efficiency of IBEM. It is found out that
IBEM dominates direct BEM in terms of time consumption in all trials. The iterative method seems very useful for quick
assessment of a wing in ground proximity condition. After all, a NACA6409 wing section in ground vicinity is solved
with IBEM to evaluate the WIG effect.
(WIG) effect. IBEM is a fast and accurate method used in many different fields of engineering and in this work; it is
applied to a fluid flow problem assessing a wing in ground proximity. The theory and the developed code are validated
first with other methods and the obtained results with the proposed method are found to be encouraging. Then, time
consumptions of the direct and iterative methods were contrasted to evaluate the efficiency of IBEM. It is found out that
IBEM dominates direct BEM in terms of time consumption in all trials. The iterative method seems very useful for quick
assessment of a wing in ground proximity condition. After all, a NACA6409 wing section in ground vicinity is solved
with IBEM to evaluate the WIG effect.