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Current Possibilities in Use of a Centrifugal Pump in the Cardiac Sugery
Mlejnský, František ; Lindner, Jaroslav (advisor) ; Lonský, Vladimír (referee) ; Vaněk, Tomáš (referee)
Current Possibilities in Use of a Centrifugal Pump in the Cardiac Sugery Abstract Currently, the most commonly used technical solution for pumping blood during extracorporeal circulation during cardiac surgery, as well as for some types of ECMO (extracorporeal membrane oxygenation) are either a roller pump or centrifugal pump. Due to its advantages the centrifugal pump is mainly used for prolonged extracorporeal circulation in cardiac surgery and as a heart and / or lung support system. In current literature there is a lack of compelling scientific evidence that would clearly support its use in a routine cardiac surgery. The aim of our study was to compare both types of currently used blood pumps in longer cardiac procedures with deep hypothermic circulation arrest. In a randomized clinical study we had selected a group of patients that underwent a pulmonary endarterectomy (PEA) in order to demonstrate the positive effects of the centrifugal pump on the postoperative inflammatory reactions. There were no statistically significant differences between these two pumps when other clinical and laboratory parameters were observed. Based on the hypothesis that significant temperature changes during cardiac procedure with a deep hypothermia can affect sealing pressure of the endotracheal tube cuff, we performed a...
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Influence of the impeller eye on the stability of Q -Y curve
Broža, Martin ; Dobšáková, Lenka (referee) ; Haluza, Miloslav (advisor)
The master thesis is focused on the examination of the influence of the impeller eye on the stability of Q-Y curves. It is the examination of the impact of a large inlet angle of the blade and the extension of the inlet part, which also supports good cavitation capabilities. Another consideration is the influence of the rotating fluid before the impeller, influence of the circumferential component of the absolute velocity at the inlet part. The proposed modification will be subject to simulation in ANSYS.
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Analysis of the Velocity and Pressure Fields of the Liquid Using Curvilinear Coordinates
Stejskal, Jiří ; Kozubková, Milada (referee) ; Kučera,, Radek (referee) ; Veselý, Jindřich (referee) ; Pochylý, František (advisor)
This work introduces a new method of hydraulic design of a centrifugal pump impeller. This method is based on a geometrical approach employing curvilinear coordinates that are used to formulate both the axisymmetrical flow model in a meridional shape and the final model of flow in a blade cascade taking into account the full 3D shape of the impeller blade. The solution to this model then directly provides the guidelines for shaping the impeller blade in order to suppress the secondary flows, thus increasing the impeller efficiency, which is demonstrated on a real impeller design case. The partial differential equations describing the flow in the blade cascade are numerically solved piecewise on each particular stream surface, which leads to a significant reduction of computational time.
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Design of Centrifugal Pump Using Differential Geometry Methods
Sloupenský, Zdeněk ; Varchola, Michal (referee) ; Melichar, Jan (referee) ; Drábková, Sylva (referee) ; Pochylý, František (advisor)
This thesis deals with a new approach to the design of impeller, blade and spiral of centrifugal pump. The mathematic model of flow inside meridional section of impeller and spiral is based on the instruments of differential geometry applied to Bezier surfaces. This formerly introduced theory is more deeply developed in this thesis and the conclusions are applied to the design of centrifugal pump parts working with fluid. The main thesis output is the mathematic model and on its principles created software determined for the design of impeller, blade and spiral. The received results are exportable into one of the commonly used 3D modeling programs.
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Dynamic radial force on centrifugal pump impeller
Nováková, Naděžda ; Hudec, Martin (referee) ; Habán, Vladimír (advisor)
This thesis deals with the radial forces acting on the impeller of a centrifugal pump. It focuses on the centrifugal pump type BETA 26. It addresses forces acting on the pump shaft. These forces are converted into the impeller. The most extensive part of this thesis is devoted to the experimental measurement and evaluation. The results are summarized and processed graphically.
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The centrifugal pump radial force reduction
Koutný, Luděk ; Haluza, Miloslav (referee) ; Pochylý, František (advisor)
This diploma thesis deals with problematics of the radial force effect on the runner and possibilities of the force reduction. Some pump modifications were proposed and changes of radial force magnitude in reverse blocking state and optimal flow state were examined in consequence. Following investigation was focused on the new modifications regarding to the pump efficiency and its characteristics stability. All results were carried out using the Solidworks, the Fluent and the Microsoft Excel software.
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Slip factor of the hydrodynamic pumps
Duda, Petr ; Archalous, Jakub (referee) ; Klas, Roman (advisor)
Bachelor thesis contains basic information about the hydrodynamic pumps. It describes the specific energy for an infinite number of very thin blade and following corrections to the finite number of blades. Part of this work is dedicated to all-weather resulting in Blade to blade channel and their effect on specific energy pump. There are illustrated by calculations of correction factors of individual authors and finally corrections are made on real three impeller wheels with a comparison of different methods.
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Slip factor of the hydrodynamic pumps
Chromek, Lukáš ; Himr, Daniel (referee) ; Klas, Roman (advisor)
This bachelor thesis deals with the initial draft of an impeller wheel, determination of its specific energy that has a pump with infinite number of impeller blades and following correction to real specific energy of an impeller wheel pump with finite number of blades. The correction will be performed using different methods by various authors and some of the methods will also be compared during the calculation of specific energy and discharge head of pump of several real impeller wheels. Then the thesis goes on to deal with some of the effects arising from the flow of fluid in the impeller wheel that often have negative influence on above-mentioned specific energy. At the end of the thesis, there will be brief abstract on problems of the correction, simulation, and analysis of flow in a blade channel using CFD software.
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