|
|
Navier-Stokesova equation - solution of the real liquid
Krausová, Hana ; Čermák, Libor (referee) ; Fialová, Simona (advisor)
This thesis deals with the Navier-Stokes equations for real, compressible fluid with first and second viscosity. The method of expansion into a series of eigenmodes of vibration is chosen to solve the Navier-Stokes equations. The general relations of the expansion coefficients and the eigenmode shapes are given for 1D-, 2D- and 3D-flows. The specific formulae of eigenmodes of vibration are determined only for 1D-flow. The final form of the pressure function is analysed using Matlab software.
|
|
|
Characteristics of gels used in the fluids engineering
Hudák, Igor ; Habán, Vladimír (referee) ; Fialová, Simona (advisor)
Not only in common life, but also in the technical area the usage of gels presents some kind of standard. Gels offer a unique possibility of usage in numerous areas. The gel structure itself is a very interesting material however it’s hard to specify its characteristics. The gel system presents a huge macromolecular network which enables to observe its different characteristics in comparison to other materials. In some circumstances gels act almost as conventional materials, in other circumstances, however, they act significantly otherwise. Therefore this bachelor thesis deals with a description and summarization of single characteristics of gels in chosen branches of the mechanical engineering industry where gels are used on a daily basis, such as sealant of pipeline systems, wires or electronic components. The thesis also describes principles of gel formation, with the emphasis to building of gel substance and with respect to its mechanical and physical features. In the end, the thesis gives a comparison of chosen characteristics of gels that are used as sealants and gels that are used for encapsulation of electrical set.
|
|
|
Vortex pump as a possible heart replacement
Coufalík, Martin ; Klas, Roman (referee) ; Klas, Roman (referee) ; Fialová, Simona (advisor)
The diploma thesis deals with the issue of artificial hearts and ventricular assist devices. The theoretical part describes the heart and its function. Blood is characterized in terms of rheological behavior and the possible criteria for hemolysis are discussed. The following section describes the most commonly used ventricular assist devices, with emphasis on the use of the regenerative pump, including its components. In the practical part, an experimental analysis of two pumps (COV 43 and COV 23) is performed. Furthermore, non-dimensional characteristics of the pumps are constructed using the laws of similarity. In the computational part, the CFD analysis of the regenerative pump is performed by means of stationary and transient calculation. The results are compared with the experimental findings and based on the results, the impeller of regenerative pump was modified.
|
|
| |
|
|
Modification of Navier_Stokes equations asuming the quasi-potential flow
Navrátil, Dušan ; Pochylý, František (referee) ; Fialová, Simona (advisor)
The master's thesis deals with Navier-Stokes equations in curvilinear coordinates and their solution for quasi-potential flow. The emphasis is on detailed description of curvilinear space and its expression using Bézier curves, Bézier surfaces and Bézier bodies. Further, fundamental concepts of hydromechanics are defined, including potential and quasi-potential flow. Cauchy equations are derived as a result of the law of momentum conservation and continuity equation is derived as a result of principle of mass conservation. Navier-Stokes equations are then derived as a special case of Cauchy equations using Cauchy stress tensor of Newtonian compressible fluid. Further transformation into curvilinear coordinates is accomplished through differential operators in curvilinear coordinates and by using curvature vector of space curve. In the last section we use results from previous chapters to solve boundary value problem of quasi-potential flow, which was solved by finite difference method using Matlab environment.
|
|
|
Magnetic field effect on the flow character close to the surface
Buday, Jakub ; Šedivý, Dominik (referee) ; Fialová, Simona (advisor)
The aim of this bachelor´s thesis is to discribe basic properties of flow and magnetic field. Further characterize different applications of magnetic fluids. Also discribes the influence of magnetic field on some properties and behaviours of water. This thesis is comparing several conlusions of scientific articles, that are examining this subject. In the experiment the changes of three fluids were observed by the help of high speed camera. The contact angle of fluids before and after exposing to magnetic field is compared. In the second part of the experiment behavior of flowing drop through magnetic field is observed.
|
|
|
Mechanical properties of cell membranes
Pírková, Marcela ; Pochylý, František (referee) ; Fialová, Simona (advisor)
This thesis is a research character focused on the analysis of mechanical properties of cell membranes. The main aim is to find methods that will break the structure of the membranes. In addition, the thesis deals with the microorganisms living in the reservoirs of the Czech Republic, the existing methods of water purification and the specific properties of microorganisms membranes. In the experimental part there is an attempt of hydrodynamic cavitation, the whole process is tested on biomass of cyanobacteria.
|
|
|
Artificial heart on the principle of gas accumulators
Kunický, Ondřej ; Fialová, Simona (referee) ; Pochylý, František (advisor)
The diploma thesis deals with the design of an artificial heart based on the principle of gas accumulators. The introductory part describes the anatomy and physiology of the human cardiovascular system, mechanical heart replacement and the basic properties of pneumatic mechanisms. Furthermore, there is shown the procedure of pneumatic circuit design and its simulation in the program Simulink. The experimental part contains verification of the functionality of the pneumatic circuit, designed the positive displacement pump, and the measured characteristics of both ventricles. The last part of the work deals with the reduction possibilities of dimensions and weight of the whole mechanism. There is also included computational modelling of the pneumatic circuit using helium as a working medium.
|
|
|
Flow through the artifitial heart valve
Šedivý, Dominik ; Pochylý, František (referee) ; Fialová, Simona (advisor)
The presented thesis solves a flow through the artificial heart valves. The thesis concerns with a historic development of mechanical heart valves and their basic parameters. It also includes a short research about Dynamic mesh module, which is contained within ANSYS Fluent. An experiment with a real mechanical heart valve was done within the diploma thesis and obtained data were compared with physiological ones. One part of this work was a design of 3D model of real heart valve replacement. The model was used for fluid dynamic computations using the Dynamic mesh of ANSYS Fluent software. In the end are the results of experimental part and numerical solutions used for few suggestions that could improve the function of the artificial heart valve.
|
|
|
Study of the flow at the interface of immiscible liquids
Lunda, Filip ; Pochylý, František (referee) ; Fialová, Simona (advisor)
This theses deals with flow of two immisible fluid in horizontal pipeline. First part teoretically describes immisible flow. What follows is experimental measurement in wich experimental track was adjusted for inlet of oil from the top. Water and corn germ oil were used as fluids. There were observed many modes of flow on the track. After that PIV was described and measured. PIV was done for measurement of values of velocity vectors. Simulation of one chosen mode was developed in the last chapter. This simulation was done in Ansys Fluent with help of VOF method. Simulation was done both in 3D and 2D pipeline. In the end these simulation were compared with experiment measurement and were critically evaluated.
|
guest ::
RSS feed.