|
|
Modal Analysis of the Swirl Turbine Rotor Blades
Pekar, Marek ; Chromek, Lukáš (referee) ; Lošák, Petr (advisor)
The aim of this diploma thesis is to determine and compare modal properties of four swirl turbine wheels, each with a different geometry. Natural frequencies and mode shapes were obtained based on computer modelling using Ansys software and they were compared with experimental modal analysis' results. The computer modelling and the experimental modal analysis were carried out for different boundary conditions and in different environments. The beginning of the thesis is dedicated to a brief overview of literature with similar issues. Then a brief introduction of a dynamics theory is mentioned in which equations of motion for a damped and an undamped single degree of freedom system are derived. The creation of a geometry model which is obtained by a reverse engineering is shown in the second part of the thesis. The geometry model was subsequently used for the computer based modelling of the modal parameters. In the third part an experimental equipment, setting, measurement and processing of data are described. The conclusion of the thesis is dedicated to the comparison of the results obtained by the experimental modal analysis and the computing modelling is presented. Moreover, influence of boundary conditions and influence of the environment on the natural frequencies are evaluated.
|
|
|
Seismic Analysis of The Pump 200-QHD
Čapičík, Martin ; Chlud, Michal (referee) ; Lošák, Petr (advisor)
The main goal of this thesis is dynamic analysis of shaft of booster pump QHD-200. In the beginning we offer basic equations generally used in dynamics and common/possible methods for their solution. Then we focus on specific problems connected with rotor dynamics and using simple Laval rotor we show their mathematical interpretation. Based on given load as accelerogram we create response spectrum in different ways (using different methods) and compare their CPU time demand. In the next part we make three finite element models of different physical level. We perform modal analysis and comparison of eigen frequencies, mode shapes. In following chapter transient analysis was performed on all models. As load we use accelerogram. We evaluate translations in particular positions of model. After that, we decide whether or not gap between impeller and stator case will be erased. Finally we make assessment of force acting upon bearings.
|
|
|
Modal Analysis of the Blades Row Tied with Z-tie
Valoušek, Tomáš ; Chromek, Lukáš (referee) ; Lošák, Petr (advisor)
This thesis is about modal analysis of the rotor blades row tied with Z-tie. Thesis was solved by finite element system ANSYS. Cyclic symmetry was used in this thesis with the aim of obtain eigen frequency of bladed disc. The next aim of this thesis was to find eigen frequency of the free rotor blades and to compare it with frequency obtained from experiment. 3D model was created by 3D scanner and CAD system CATIA.
|
|
| |
|
|
Standardized procedure of the machine tool adjustment for change of the machined part type
Nedoma, Tomáš ; Tuna, Jaroslav (referee) ; Lošák, Petr (advisor)
The bachelor thesis at hand is dealing with standardized procedure of machine adjustment in process of machined rail type change in Bosch Diesel s.r.o. Jihlava. In the thesis, procedures of external adjustment of preparations that clamp workpieces into machining centers and overall procedure of machine adjustment are described. The elaborated standardized procedures are included in instruction manuals, which are used by workers of the company for machine adjustments. These “manuals” shall minimize occurrence of defective steps in the adjustment process and prevent their interchange. Mistakes based in incorrect procedure of the workers lead to prolongation of the time necessary for machine adjustment in process of change of machined type by up to hundreds of minutes per month. Bosch Diesel s.r.o. has adopted these instruction manuals and thanks to them shall save couple of tens of thousands euro per year.
|
|
| |
|
|
Analyses of Mechanical Tasks in Multi-body System
Ondrejka, Adam ; Lošák, Petr (referee) ; Hadaš, Zdeněk (advisor)
The aim of the bachelor thesis is to create simulation models according to mechanical tasks with the usage of CAD system Invetor and simulation tool SimMechanics, which will be further utilized in tuition. The accuracy of simulation would be evaluated in comparison with classic solutions. Finally, the pros and cons of SimMechanics would be summarized.
|
|
|
Modelling of dynamics systems with multi degrees of freedom
Světnický, Tomáš ; Lošák, Petr (referee) ; Dušek, Daniel (advisor)
The goal of this thesis is to create a mathematical model of multi-degree-of-freedom vibrating system based on motion equations. The introduction describes the theoretical distribution of dynamic vibrating systems and their main characteristics. The next part deals with the analysis of assigned system and the motion equations are constructed by using Lagrange equations of the second kind. The process of system solving is provided together with equations which were used for obtaining the natural frequencies, eigenmodes and amplitudes of objects in time. The actual solution is carried out in MAPLE software; graphs of amplitude characteristics, phase characteristics and objects amplitude in time are constructed. Influence of parameters entering the calculation is discussed. At the end is verified the accuracy of the analytical solution by the finite element method in ANSYS software.
|
|
|
Comparision of methods for nonlinear dynamic sytems solution
Krejčí, Jaroslav ; Lošák, Petr (referee) ; Dušek, Daniel (advisor)
The aim of this work is to make a solution of nonlinear dynamic system with one degree of freedom using various approximate analytical methods and perform their comparison. The beginning of the work describes the basic characteristics of nonlinear dynamic systems, methods of modelling and a description of the basic analytical methods of solution. In the following part is the solution of the system using described methods and comparing of results. In conclusion the methods are compared with final element method by program ANSYS.
|
|
| |
guest ::
