|
|
Mathematical-physical analysis of dynamic pressure for the experimental differentially pumped chamber
Lepltová, Kristýna ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
This thesis is based on the series of scholarly article dedicated to the issue of pumping in the differential scanning chamber of an environmental scanning microscope. The thesis is based on Danilatos’s study where the pumping of the differential pumped chamber is solved by means of the Monte Carlo statistical method. The thesis analyzes gas flow in the experimental chamber using the Pipot tube. The analyses will be used for the design of the experimental chamber which will serve for the experimental evaluation of the flow results in the chamber using the continuum mechanics.
|
|
|
Numerical model of ultrasonic oil level sensor
Chutný, Pavel ; Bílek, Michal (referee) ; Vyroubal, Petr (advisor)
This master’s thesis verifies physical principle of ultrasound in fluids by numerical model. At first, ultrasound study is ment. In second theoretic part, diferent kind of motor oils are described. Next, equations for numerical simulation are presented. In practical part, numerical model of level sensor is examined in well-knowed fluids (water, air). Results of laboratory measurement on topic of ultrasound velocity in oil dependent on temperature are aplicated on numerical model of sensor and optimalized.
|
|
|
Analysis of the impact of the conic aperture placement in the supersonic flow in the differentially pumped chamber
Rous, Miroslav ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The thesis is focused on the medium dynamics simulation in the environmental scanning electron microscope. Specifically, it researches (examines) the conical aperture location effect in the differential pumped chamber and the width of the pumping channel in this chamber. The theoretical part deals with the environmental scanning microscope generally and other tools used in this thesis, e.g. ANSYS Fluen software, fluid turbulence, medium free path of molecules and electrons scattering. In the practical part, the work is focused on data processing from the ANSYS Fluent program and on their evaluation.
|
|
|
Analysis of the shape of the intake ports of the current concept differentially pumped chamber
Bílek, Michal ; Vyroubal, Petr (referee) ; Maxa, Jiří (advisor)
This master´s thesis discusses the analysis of the shape of the intake ports of differentially pumped chamber for the current concept. The first part is an introduction to the microscopy issue, then it is focused on ESEM microscopes and it also includes a describtion of the Flow dynamics and a mathematical describtion. In the following chapters the software Solid Works, where the model of differentially pumped chamber is created, and the software Ansys Fluent, which is used for analysis, are described. The second part concerns the proposed concepts and the results of their simulations. At the end of the work the results are analyzed and evaluated.
|
|
|
Control of the laboratory model of synchronous drives
Koubík, Martin ; Bílek, Michal (referee) ; Zezulka, František (advisor)
The aim of this theses describes the design of the control program for the synchronous axes model and reconstruction of this model. The first main part is description of synchronous axes model, description of engines and other components of model. Then model modifications are described. Another part is discussing the TwinCAT programming environment and describe all important elements that must be performed for proper functionality of the model. There is also a description of function blocks that are used to program motion sequences. The last part is described of demonstration program and program which would be used for teaching.
|
|
|
SW model of PLC controlled crossing
Simon, Jakub ; Bílek, Michal (referee) ; Zezulka, František (advisor)
The objective of this thesis is to create a software model to control various types of crossroads using programmable logic controller. The control system is created on Siemens PLC SIMATIC S7-300. The programmes of system are written in different programming languages such as GRAPH, STL, LAD. The visualisation is also created to control by using of SCADA system InTouch from the company Wonderware. The visualisation comunicates with the PLC using a DAServer. The visualisation has both, input and output elements, so it is not intended for supervising the run of the control system only, but also for simple user‘s control, using a graphical user interface. It is possible to control the start and stop events of the system, and to switch between different crossroad's control modes and also to trigger the pedestrian's button.
|
|
|
Analysis of the impact of the baffle placement in the supersonic flow in the differentially pumped chamber
Vlasáková, Martina ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
This thesis deals with the area of the differential pumping chamber of an environmental scanning electron microscope, engaging the pressure limiting apertures and the influence of the enclosure inside the chamber. In the theoretical part, it is first called Microscopy as science, information about microscopes (division of microscopes) and electrons. Afterwards, the theory deals directly with environmental scanning electron microscopy and its problems and vacuum system, mathematical models and computational areas, basic information about the comparative study from, which the thesis is based. In the experimental part there are presented the objectives of the work and the chapter dealing with the processing of results, which are compared with the initial study using the program Ansys Fluent.
|
|
|
Specifications of the Ansys Fluent Solution Solver for low pressures in EREM
Šimík, Marcel ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
This thesis is focused on electron microscopy which issue is discussed at the beginning of work. The main attention is dedicated to the Environmental electron microscope, especially the differentially pumped chamber, which the thesis deals with. There is a production of an experimental chamber for analysis of shock waves on going therefore main goal of this thesis was to analyze the flow pattern in this chamber. Using the Ansys Fluent program, simulations of the characteristic flow that arises from the pumping of the vacuum chambers namely the ultrasonic flow at low pressures on which the most suitable turbulent module was applied as well as the degree of discretization was performed. The final analysis of this flow pattern is primarily focused on the localization of the shock wave which experimental evidence is to be lodged by shadow optical method as a part of the new concept of the chamber. The basis for the simulation of the chamber was taken over by Dr. Danilatos, with which the results were compared.
|
|
|
FLOW ANALYSIS OF THE PRESSURE IN THE EXPERIMENTAL CHAMBER OF THE DIFFERENTIAL PUMPING
Šabacká, Pavla ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The thesis deals with the effect of the critical flow, which is produced at pumping of the differential pumping chamber of the Environmental Scanning Electron Microscope (ESEM). The thesis compares the state of the flow in the area of pumped chamber at pressure ratio on the apertures when the critical flow occurs and its advantages in design of the chambers versus the flow without the clogging the nozzle. Problematics were solved using finite volume method by Ansys Fluent system.
|
|
| |
guest ::
RSS feed.