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Öğe Design of a biomimetic wing from maple samara and investigation of the aerodynamic performance(Aip Publishing, 2023) Caliskan, Mehmet E.; Kaya, Fuat; Sabirli, Muhammet U.; Karagoz, IrfanThe morphological structure and airborne behavior of maple samaras have attracted increasing attention due to their potential use in wind turbines and air vehicles. This study introduces a new methodology based on mathematical modeling to transfer the geometric structure of maple samaras to a virtual environment and presents an experimental and numerical investigation of the performance of a model wing designed with this method. Certain sections were taken along the structure of maple samaras, measurements were made, curves were obtained mathematically for each section, and these curves were transferred to a design program. A biomimetic three-dimensional model was generated by combining these curves. The mathematical modeling of these curves was obtained with certain degrees of expansion of the Fourier series. Experimental and numerical studies of the designed biomimetic model were performed at different free stream velocities and angles of attack. The trend of the lift coefficient curves indicated that the samara wing model has a larger range of angle of attack, up to 40(circle)-45(circle) without a stall, and the maximum lift to drag ratio (CL/CD) was obtained at 8(circle) angle of attack. In addition, the present model showed more stable performance, and the lift and drag forces did not change as much as in conventional blades at varying free flow velocities. In the analysis results, the air flowing over the wing caused the formation of these vortices inside the ordered trough top structures of the model. These vortices, seen from the leading edge, are thought to play an effective role in the lift coefficient of the biomimetic samara model.Öğe Effects of Surface Roughness on the Performance of Tangential Inlet Cyclone Separators(TAYLOR & FRANCIS INC, 2011) Kaya, Fuat; Karagoz, Irfan; Avci, AtakanThis study is carried out to investigate the effects of surface roughness on the flow field and cyclone performance. The flow inside the cyclone separator is modeled as a three-dimensional turbulent continuous gas flow with solid particles as a discrete phase. The continuous gas flow is predicted by solving the governing equations by using the Reynolds Stress turbulence model, and the modeling of the particle motions is based on a Lagrangian approach. The results of the numerical simulations are compared with experimental data as well as with the results of mathematical models. Analysis of computed results shows that increase of relative roughness due to corrosion, wear, or accumulation of particles on the inner walls considerably influences the tangential velocity, cyclone separation efficiency, and cyclone pressure drop especially for high inlet velocities. Decreases in cyclone collection efficiency and pressure drop with the increase in surface roughness are found to be more pronounced for high values of relative roughness.Öğe Experimental and numerical investigation of pressure drop coefficient and static pressure difference in a tangential inlet cyclone separator(VERSITA, 2012) Kaya, Fuat; Karagoz, IrfanThe aim of this study was to investigate the pressure drop coefficient and the static pressure difference related to the natural vortex length and to evaluate the results for gas-particle applications. CFD simulations were carried out using a numerical technique which had been verified previously. Results obtained from the numerical simulations were compared with the experimental data. Analysis of the results showed that the pressure drop coefficient decreases with the increasing inlet velocity, becoming almost constant above a certain value of the inlet velocity. The reason is that the effect of viscous forces decreases at high Reynolds numbers. The pressure drop coefficient also decreases with the increasing exit pipe diameter and decreasing exit pipe length.