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FLow in cracs
Ocásek, Adam ; Veselý, Jindřich (referee) ; Haluza, Miloslav (advisor)
This Master’s thesis investigates the flow in sealing gaps of impeller within pumps and turbines. Sealing gaps are installed to improve the volumetric efficiency in this type of fluid machinery. Despite present extensive research this subject has not been entirely documented and the thesis’ aim is to improve our knowledge in this matter. At the beginning, the practical experiment is used in order to establish appropriate numerical description of flow in seals and to calibrate software FLUENT. In chapter five, the thesis analyses the influence of seal design on volumetric efficiency of pumps and turbines and defines its optimal construction to improve the efficiency. The thesis then examines the effect of rotor eccentricity on flow properties, flow rate and pressure distribution within the sealing gap. In the last section, through chapters six to eight, the flow results provided by numerical solution in FLUENT and selected analytical equations, or their modified forms, are being discussed. The degree of correspondence between the results is also studied.
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Valveless Plunger Pump
Machů, Tomáš ; Kozubková, Milada (referee) ; Melichar, Jan (referee) ; Pochylý, František (advisor)
This thesis deals with valveless reciprocating pumps. Within the thesis several designs of pump geometry are demonstrated. Their parameters were obtained using computational fluid dynamics. Reciprocating piston movement was simulated by time dependent inlet boundary condition or by dynamic mesh. The individual variants were compared mainly from point of view of volumetric efficiency, which was the main evaluated parameter. Results of calculations are presented as dependencies of volumetric efficiency on frequency and amplitude of piston motion and on value of backpressure. Two variants of the prototype pump geometry were manufactured to experimentally validate parameters obtained from calculations. Volumetric efficiency together with hydraulic efficiency were evaluated from measured data.
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Valveless Plunger Pump
Machů, Tomáš ; Kozubková, Milada (referee) ; Melichar, Jan (referee) ; Pochylý, František (advisor)
This thesis deals with valveless reciprocating pumps. Within the thesis several designs of pump geometry are demonstrated. Their parameters were obtained using computational fluid dynamics. Reciprocating piston movement was simulated by time dependent inlet boundary condition or by dynamic mesh. The individual variants were compared mainly from point of view of volumetric efficiency, which was the main evaluated parameter. Results of calculations are presented as dependencies of volumetric efficiency on frequency and amplitude of piston motion and on value of backpressure. Two variants of the prototype pump geometry were manufactured to experimentally validate parameters obtained from calculations. Volumetric efficiency together with hydraulic efficiency were evaluated from measured data.
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Vliv konstrukčních změn sacího a výfukového traktu na výkonové a emisní parametry motoru
Šenkyřík, Michal
This thesis deals with the design changes of intake and exhaust systems of naturally aspirated combustion engine with the aim to improve its dynamic characteristics. An overview of intake and exhaust tract designs (together with their impact on the engine efficiency) is provided in the introductory part of the thesis. Based on this knowledge, modifications of the intake and exhaust systems of Ford Windsor V8 engine were proposed and installed in a vehicle. A series of dynamic and static tests on chassis dynamometer were carried out in order to measure the impact of the changes on the torque curve. The impacts of the changes are presented in detailed analysis of power and torque characteristics with respect to the engine speed. The results are discussed and the possible causes of observed phenomena are identified.
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Indikace spalovacích tlaků zážehových motorů
Linhart, Roman
The thesis deals with the indication of combustion pressures of ignition engines. Introduction is devoted to thermodynamics of combustion engines and their diagrams. The following section describes the methods for measuring the combustion pressures of a spark ignition engine. This chapter describes three basic methods of measurement, the most described of which are piezoelectric sensors. The next part is devoted to the design of the measuring chain and to the description of the material used, which was used for the measurement on the engine under test. The main goal of the thesis was to evaluate the results obtained by measuring at the engine testing center of Mendel Uni-versity in Brno. The data were tabulated and graphically evaluated and subsequently described. At the end of the thesis everything is evaluated and the results summarized.
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FLow in cracs
Ocásek, Adam ; Veselý, Jindřich (referee) ; Haluza, Miloslav (advisor)
This Master’s thesis investigates the flow in sealing gaps of impeller within pumps and turbines. Sealing gaps are installed to improve the volumetric efficiency in this type of fluid machinery. Despite present extensive research this subject has not been entirely documented and the thesis’ aim is to improve our knowledge in this matter. At the beginning, the practical experiment is used in order to establish appropriate numerical description of flow in seals and to calibrate software FLUENT. In chapter five, the thesis analyses the influence of seal design on volumetric efficiency of pumps and turbines and defines its optimal construction to improve the efficiency. The thesis then examines the effect of rotor eccentricity on flow properties, flow rate and pressure distribution within the sealing gap. In the last section, through chapters six to eight, the flow results provided by numerical solution in FLUENT and selected analytical equations, or their modified forms, are being discussed. The degree of correspondence between the results is also studied.
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