|
|
Influence of Centrifugal Compressor Acoustic and Operating Parameters by Stator Geometry Modifications
Vacula, Jiří ; Vítek, Oldřich (referee) ; Babák, Martin (referee) ; Novotný, Pavel (advisor)
The increasing demands on the operational capabilities of rotating machines are mutually reflected in the ever-increasing computational capabilities. This makes it possible to analyse very detailed aerodynamic phenomena and to investigate the detailed effects of lesser-known aerodynamic principles. The standard aerodynamic design of a centrifugal compressor consists of an open impeller containing a smooth stator; however, the shape of the stator also contributes to the resulting parameters of a rotating machine. Thus, in this paper, the effect of stator geometry is first analysed qualitatively by analytical methods based on the analysis of the Navier-Stokes equation. Next, the influence of stator geometry is investigated by a Computational Fluid Dynamics (CFD) tool using circumferential casing treatment. The experimentally measured circumferential grooving of GT15 compressor shows that the quality of the treated surface can have a significant effect on the resulting performance of the rotating machine. Another measured casing treatment variant of the GTD2056 compressor shows an increase in efficiency of 0.5% and a marginal effect on aerodynamic noise. The relationship between the efficiency increases and losses is analysed using a viscous dissipation function that directly points to the influence of the flow field due to the geometric modifications of the stator and is shown to be largely conclusive for describing the losses in the impeller region.
|
|
|
Improvement of turbocharger inlet manifold parameters
Kula, Štěpán ; Vacula, Jiří (referee) ; Novotný, Pavel (advisor)
The bachelor thesis deals with the design of a new elbow geometry to reduce the pressure drop in the inlet suction pipe of a turbocharger compressor. At the beginning of the thesis there is a description of the fluid flow and hydraulics losses that result in pressure loss in the pipe. Next, possible methods by which the shape of the piping can be optimized are described. The last, main section deals with the actual optimization of the elbow using the manual method and the Adaptive Single-Objective method, which succeeded in reducing the pressure losses and improving the outlet flow profile.
|
|
|
Aerodynamic components of passenger cars
Petrskovský, Adam ; Vančura, Jan (referee) ; Vondruš, Jan (advisor)
This bachelor thesis is focused on aerodynamics of the cars. Theories on aerodynamics characterizations as well as force exertions are presented here. Moreover, the influence of aerodynamics on fuel consumption and formation of harmful emissions is described. The thesis also provides a comprehensive overview of particular aerodynamic devices used on cars. Furthermore, CFD simulations of four aerodynamic devices on a simplified model of car are included. The results of these simulations are then evaluated and the respective aerodynamic devices are subsequently compared to find out which of them has contributed the most to the improvement of aerodynamic characteristics of the vehicle.
|
|
|
Equipment for drying durable "Biltong" meat with warm air
Gabriel, Jan ; Foltýnová, Dana (referee) ; Čípek, Pavel (advisor)
This bachelor's thesis deals with the design proposal of a meat dryer of the "Biltong" type. The aim of the thesis is to design the construction of the device according to the given parameters. The first part of the thesis consists of a research of current principles and equipment used for meat drying. In the second part, possible conceptual variants are described. Based on the conceptual part with regard to the assignment, suitable components of the dryer are selected. The practical part then deals with the performance design and construction solution of the dryer.
|
|
|
Quantitative comparison of used mesh for CFD software ANSYS Fluent
Koudelková, Kateřina ; Klas, Roman (referee) ; Štefan, David (advisor)
Creating a good computational mesh is one of the crucial activities in any CFD calculation. CFD software aim to make a mesh generation as simple and automated as possible, due to its time-demanding nature. ANSYS Fluent has introduced a tool for partially automatic mesh generation, a method called Mosaic mesh, which should ensure that the best type of mesh element is used in each part of the geometry for optimal results. Polyhexcore is the latest computational mesh generation method used by Mosaic mesh technology. This thesis aims to compare the Polyhexcore mesh with other types of computational meshes on an aerodynamic test problem.
|
|
|
Post-war automotive aerodynamics
Šmerda, Ondřej ; Vančura, Jan (referee) ; Čavoj, Ondřej (advisor)
This Bachelor thesis deals with charting the development of the automotive aerodynamics in the post-war period. It focuses on principles that go along with car design. The development is demonstrated by aerodynamically significant and unusual cars including racing and record cars. Last but not least, the work compares those cars with today's cars and describes drawbacks of the cars of the given period from today's perspective.
|
|
|
Modeling of flow on synchronous generator
Chlup, Jaroslav ; Skalka, Miroslav (referee) ; Janda, Marcel (advisor)
This project deals with simulation´s possibilities of air flow in electric machines. A finite element method is the final element technique. Aim of this project is conversion universal formula for calculation friction dissipation factor. For its location is necessary to create 27 simulations according to the 2. plan order. Usage programme MATLAB for processing results obtain requisite algorithm for calculation friction dissipation factor.
|
|
|
Experimental determination of the hydrodynamic load of the flooded bridge model
Naiser, Dominik ; Hrdlička, Libor (referee) ; Zubík, Pavel (advisor)
The diploma thesis deals with experimental determination of hydrodynamic load on the overflowed bridge deck model. In the first part of the thesis the author describes the analysis of the problem together with the basic physical laws and principles that are used or assumed in the measurement itself. In the second part the author describes the measurements in the laboratory of the Faculty of Civil Engineering and its gradual processing. At the end of the work are described the results of measurement, their comparison with numerical modeling, other authors and their possible use in practice.
|
|
|
Visualization of air jet from ventilation outlet of a passenger car dashboard
Bečica, Radek ; Bělka, Miloslav (referee) ; Lízal, František (advisor)
Goal of this master´s thesis is to experimentally analyse air jet from ventilation outlet of a passenger car dashboard using smoke visualization and to describe this air jet. Air flow was set at 30 m3/h according to requirements from Škoda Auto s.r.o. from previous experiments on a similar ventilation outlet. First type of measuring rig which was developed for previous experiments was disassembled and replaced with a new modern measuring rig which is supposed to be used for next visualizations and experiments. Visualization was performed using smoke method and laser light plane. Air jet was photographed for five defined ventilation outlet adjustments and that for a jet to free space and for a jet flowing along a wall. The wall represented a front left door of a car. Results were processed by computer and presented as pictures and tables. Resulting angles were transformed to the main coordinate system of a car. Ventilation outlet functionality with respect to the air distribution in a car was evaluated afterwards.
|
|
|
Pulse flow of liquid in flexible tube
Komoráš, Miroslav ; Šedivý, Dominik (referee) ; Klas, Roman (advisor)
This master’s thesis is dealing with analysis of fluid flow pulse in a flexible tube representing e.g. an artery in a human body. In ANSYS program, 3D simulations were performed, and these are so-called interrelated FSI analysis. In Maple software, 1D simulations of fluid flow in the tube were performed for various thin-walled and thick-walled variants. The aim is using these programs to determine the flow rates and pressures in the tube, its wall deformation and stress. Therefore, the theoretical part deals mainly with basic equations of flow dynamics, linear and nonlinear models and rotationally symmetric vessels. In the computational part are described individual procedures in the mentioned programs.
|
guest ::
