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Parameters for 1D Single Cylinder Engine Simulation
Stryja, Štěpán ; Šebela, Kamil (referee) ; Janoušek, Michal (advisor)
The relationship between the 1D simulation and the corresponding input parameters is addressed in the paper. The one-dimensional simulation is demonstrated in the GT-Power environment. The work deals with both experimental and computational analysis of the input parameters. Additive methods of 3D printing of fixtures and subsequent measurement of volumetric flow rates on a Superflow Flowbench SF-260E purge station were used. This procedure led to the final calculation of discharge coefficients. The 3D scanning method, using ATOS 2M equipment, together with subsequent data processing, using the appropriate software, led to the analysis of the valvetrain mechanism and the construction of its kinematics. The practical part was demonstrated on two-cylinder heads of a four-stroke single cylinder engine with a displacement of 125 cm3, with natural aspiration. One of the heads was modified, resulting in volumetric flow increase of 29 % in case of the intake and 15 % in case of the exhaust, compared to the stock head. The work led to the acquisition of key input data for the 1D simulation of the aforementioned engine.
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Influence of inflow orientation on overflow characteristics over broad-crest
Major, Jakub ; Dušička,, Peter (referee) ; Fošumpaur, Pavel (referee) ; Zachoval, Zbyněk (advisor)
Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.
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Full-width thin-plate rectangular weir influenced by channel width
Zmítko, Jakub ; Roušar,, Ladislav (referee) ; Zachoval, Zbyněk (advisor)
The diploma thesis deals with the propagation of a weir (channel) width on the weir capacity. The influence rate is analyzed by laboratory measurements on models with a weir (channel) width of 0,02 m to a width of 0,50 m. Different heads are analyzed and different discharges that calculate the discharge coefficient. The results are compared with previous works, especially with the work of Kindsvater and Carter (1957) and of Schoder and Turner (1929), where the same procedures are used to calculate discharge coefficients. The thesis contains a theoretical introduction to the problem of thin-plate weirs and the problem of the formation of the boundary layer in the flow of liquid, following with the analytical part. In the analytical part, the results of measurements, their comparison, and evaluation are published. The work is completed with evaluation and recommendations.
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Discharge coefficient of slit weirs
Havran, David ; Žoužela, Michal (referee) ; Zachoval, Zbyněk (advisor)
This work deals with experimental research, with outcomes of design and recommendation for determination of the discharge coefficient of the slit weir. At the same time states the possible effects on capacity. Then comparing the data with already existing ones. The thesis provides an overview and insight into the meaning of slit weirs as well. The goal is to recommend the determination of the discharge coefficient.
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Discharge coefficients for nozzles of a low-NOx gas burner
Zifčáková, Barbora ; Bojanovský, Jiří (referee) ; Juřena, Tomáš (advisor)
Nozzles belong to the main parts of a low-NOx gas burner. Their purpose is to transport fuel into a combustion system. One way of judging a quality of a nozzle is to define its discharge coefficient. It expresses an efficiency of energy conversion – from pressure to kinetic energy. In this thesis the discharge coefficients of several nozzles were established, using Ansys Fluent software for computer simulation. A calculation was tuned to a reference geometry and then applied to other geometries of nozzles, which were both planar and spatial. Numerically obtained data were compared with experimental data. The benefits of this thesis are comparism of two main methods of flow modelling (Scalable Wall Function and Enhanced Wall Treatment) and formulation of a calculation methodology for this type of physical problem. The results provided by this thesis might be used for both another study and experimental research.
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Thin-plate rectangular weir with inlet shaft
Šváb, Jiří ; Šulc, Jan (referee) ; Zachoval, Zbyněk (advisor)
The thesis is divided into literary research and practical part (own measurement). The content of the literary research is a description of the flow over thin-plate rectangular weir. The practical part is focused on a description of the model, measuring equipment and measurement. The results are evaluation of lower and upper surface of nappe, determination of discharge coefficient, coefficient of relative length of shaft, limit value of relative length of shaft for uninfluenced shape of nappe.
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Intake Ports for the Wankel Engine
Smělý, Jiří ; Beran, Martin (referee) ; Svída, David (advisor)
This master’s thesis deals with design of intake port for turbocharged Mazda 13B-T engine with Wankel-type rotating piston motion aiming for possible modifications leading to increase of performance parameters. The main objective of this thesis is to propose appropriate modifications in order to achieve increased torque in widest possible engine speed range.
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Lateral recirculation zones of flow in approach channel of weir
Korálová, Nikola ; Pařílková, Jana (referee) ; Zachoval, Zbyněk (advisor)
The bachelor’s thesis is divided in to the literary research and practical part. The content of the literary research is the issue of side contracted weirs, where occurs side contracted flow. The sudden change of the channel width and formation of upstream wake have direct influence on value of discharge coefficient. There are described types of the weirs, ways of computing discharge and discharge coefficients which are influenced by contraction. In the practical part of thesis is described measurement of the velocity field of side contracted flow by UVP Monitor, follow up by assessment of boundary of the upstream wake, which is situated in the approach channel in front of the weir.
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