Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Design of Centrifugal Blood Pump(01. Izmir Institute of Technology, 2020) Sarızeybek, Ceren; Özkol, ÜnverIn this thesis a maglev centrifugal blood pump is studied numerically which will be used in ECMO systems. Aim was to design a pump with 3.3 L/min at 5000 rpm having 200 mmHg head. Pump is designed by SolidWork and CFD studies are applied in Ansys Fluent. Firstly, blade discharge angle values between 20 degree and 40 degree are simulated with 5 degree intervals and 35 degree is found to be the most appropriate for hydraulic efficiency and head. Likewise, six different up-clearance values between 2.0 mm and 0.1 mm are studied to see effect of up-clearance on head and efficiency. Also to predict hemolysis for different up-clearance values, Giersiepen power law hemolysis model with Lagrangian approach is employed. 0.1 mm up-clearance is found suitable. For this up-clearance hemolysis is calculated as 4%.Master Thesis Design and Numerical Analyses of Guide Vanes of a Multistage Submersible Pump(Izmir Institute of Technology, 2019) Demirtaş, Mert; Özkol, ÜnverThe objective of this thesis is to analyze a multistage submersible pump numerically, figure out the inefficient sections of flow and propose a modified design according to the simulation results. Hydraulic parts of a submersible pump are impeller, diffuser and return channel. In this study, the investigated pump’s stages have only impellers and return channels. According to the literature, the inefficiencies in pump stages might be caused by angle misalignment of impeller and guide vanes, channel geometries or vane designs. The investigated five stage submersible pump and its CAD models are provided by a manufacturing company. In the first part of the study, fluid domain is created for numerical computations and analyses are performed with ANSYS Fluent software. According to the simulation results, flow nonuniformities are observed in return channels and identified that the reason is guide vane geometry. The second part of the study includes the modified design of guide vane and set of simulations with different wrap angles to find out the optimized value. The simulation results of this thesis study are quite satisfactory when they are compared to experimental data of manufacturing company. After modifications, the nonuniformities which are observed in original design are diminished and efficiency of the pump is increased.Master Thesis Investigation of Flow Through a Semi Axial Centrifugal Pump(Izmir Institute of Technology, 2006) Karamanoğlu, Yılmaz; Mobedi, Moghtada; Mobedi, MoghtadaThe aim of present study is to perform a numerical work to investigate flow inside a semi axial centrifugal pump. The results of the study can be used to improve the design of the pump.The Navier Stokes equations with appropriate boundary conditions are solved for a 3 dimensional rotating geometry. To solve the governing equations, Fluent program is used. Fluent is a commercial CFD program, which has been developed based on the finite volume method. The mesh for the flow volume is created by Gambit.The k -e turbulence model is used to handle the turbulence inside the flow. Obtained results are compared with experimental test results. An acceptable agreement between the numerical and experimental results is observed.Based on the obtained results, the velocity vectors, pressure distributions on impeller and diffuser blades and flow patterns are plotted for three different flow rates.The necessary discussions are performed for these results. It is observed that the design of the impeller provides a regular flow inside the channel; however some vortexes are observed in the channel between the diffuser blades.The effect of the surface roughness is also investigated and the problem is solved for four different roughness values (0, 50, 100 and 250 m). It is found that the roughness of the surface affects the characteristic curves of the pump. By increasing the roughness, the head and efficiency of the pump decrease however the consumed power is almost constant.