National Repository of Grey Literature 173 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Pressure drop in the flow of the liquid in the tube with very high roughness
Habr, Martin ; Rudolf, Pavel (referee) ; Habán, Vladimír (advisor)
The thesis deals with sources of the head loss in pipe and options of its calculation. Factors influencing the head loss and possibilities of decreasing pressure drop in pipe are also discussed in the thesis. The result of thesis contains comparison of calculation methods of head loss with calculation using Darcy-Weisbach equation.
Design and lay-out of high pressure pumping station.
Václavík, Tomáš ; Franc, Zdeněk (referee) ; Habán, Vladimír (advisor)
The aim of diploma thesis is design and lay-out of high pressure pumping station with plunger pumps for splash of scales from slabs of hot-rolled. Theoretic (introduction) part of this thesis contain description of formation of scales and description of ways how it is possible remove these scales. And this part contains also explication of effect of water jet on solid material. The practical part of diploma thesis is focused on design of pumping station including of dimensioning of machinery. Part of this work is also technical documentation for proposed pumping station and specification of main machines and devices.
Optimisation of Flow Rates in Lubrication Systems with Progressive Distributors by means of Genetic Algorithms
Vepřek, Jiří ; Pavlok, Bohuslav (referee) ; Bauer, František (referee) ; Habán, Vladimír (referee) ; Nevrlý, Josef (advisor)
This doctoral thesis presents the results of the development of two software programs for the design of progressive distributors and progressive lubrication systems. One of these programs implements a genetic algorithm and the other, which is used to design progressive lubrication systems, implements a parallel genetic algorithm of the island model. The program for the design of progressive distributors was implemented in Java using the NetBeans development environment and the other program was created in Matlab. The thesis further focuses on analytical and computational solutions of the flow of compressible greases seen as viscoplastic fluids. Equations for the numerical solution of the non-steady flow of compressible viscoplastic Bingham fluids were derived and solved by the Lax-Wendroff method in Matlab. As several constants had to be set in the equations, experiments were conducted with the ecological grease Plantogel 2S in the laboratory of the Kaplan Department of Hydraulic Machines, mainly to determine the sound velocity in this grease. The sound velocity was calculated based on the experimental results by applying Fourier transformation and the transition matrix method. In addition to this, the rheological measurements of greases were used. As seen from the results, the ecological greases are actually thixotropic viscoplastic fluids with a significant elastic element. Since a Newton fluid was assumed when calculating the sound velocity, the possibilities of using the transition matrix method for viscoplastic fluids were then considered. No analytical solution of the flow of viscoplastic fluids in a frequency spectrum has been published so far. Because it emerged that greases had a significant elastic stress factor, the problem of the non-steady flow of elastic-viscoplastic fluids was solved numerically between two infinite parallel plates by applying the finite difference method (FDM). The computation was done in Matlab. This doctoral thesis makes a contribution to solving problems related to the design of progressive distributors and progressive lubrication systems used to distribute compressible greases. Considering the complex approach to this field and the achieved results, the thesis also represents a significant contribution to design work.
Experimental verification of ejector and creation of mathematical model.
Strmiska, Michal ; Štigler, Jaroslav (referee) ; Habán, Vladimír (advisor)
This diploma thesis deals with the area of ejectors. In the intoduction, an ejector is classed as an hydraulic machine. There is also an introduction of the principle and application of this machine there. The next part describes two different ways of calculation and there is a suggestion how to get characteristics, that were achieved by calculation in MS Excel, projected. The purpose of this diploma thesis is to confront this mathematical model with the experiment done in school laboratory at Kaplan department of hydraulic machines. The description of this experiment and the evaluation procedure of measured values is described in the final part of this diploma thesis.
Simulation and damping of the excited pulsation
Kubis, Aleš ; Franc, Zdeněk (referee) ; Habán, Vladimír (advisor)
The aim of diploma thesis is design math and numeric system, which simulate these features: model of threeplunger piston pump, system of piping and damping elements. This thesis also contains chapters, which describing numeric models of particular’s elements of system with charts of function dependencies from computation’s program. The last chapter contains numeric model of treeplunger piston pump without damping elements. Continuation of my diploma thesis should be a harmonized of damping elements and designed pump.
Waterjet cutting of material
Veselý, Radek ; Foldyna, Josef (referee) ; Habán, Vladimír (advisor)
This bachelor thesis describes principles of utilization of high-speed liquid jet for material machining. In the first part, basic classification of liquid jets and brief description of devices for generating high pressure liquid is presented. Next, using of continuous jets is discussed. Main scope of this work is oriented at the use of so-called pulsed jets, especially at ultrasonically modulated ones. Break-up of ultrasonically modulated high-speed pulsed jet into single pulses, impact of such pulse on the surface of disintegrated material and subsequent erosion in the impact area are described. The comparison of efficiency of modulated and continual water jets is summarized in the last part of the thesis.
Use of standard centrifugal pump as turbine
Podešva, Adam ; Franc, Zdeněk (referee) ; Habán, Vladimír (advisor)
This work deals with the use of a centrifugal pump in turbine mode and control of the system where this machine is operated. The introduction describes and divides the various types of pumps and discusses the issue of Euler's pump and turbine equations. The flow control options are also described here. Part of the work is a research that examines the advantages and disadvantages of using a centrifugal pump in turbine mode, the possibilities of using this system and real applications in the Czech Republic and in the world. The main part is the design of a mathematical model in Microsoft Excel, which solves the regulation of the piping system with a pump operating in turbine mode, especially out of the optimal operating parameters.
Mathematical model of circuit in laboratory VUT FSI OFI.
Klapal, Tomáš ; Haluza, Miloslav (referee) ; Habán, Vladimír (advisor)
This diploma thesis deals with project and experimental verification of mathematical model of experimental circuit for measuring turbine in laboratory of Kaplan Department of Fluids Engineering FME BUT in Brno. Pressure and flow characteristics were modeled based on data measured on general-purpose experimental circuit. Possibilities of the circuit control, mainly by by-pass, were also taken into account. Characteristic curves should serve for preliminery design of the test circuit set up for the turbine model measurements.
Damping of Pressure Pulsations in Elastic Pipes
Panko, Martin ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
This diploma thesis deals with numerical simulation of pressure pulsations in elastic pipes. Continuity relation of fluid in elastic pipes, when calculating some damping in pipe material, is derived into practice. Rheological model of such a pipe corresponds to Voigt (Kelvin) model. For analysing dynamic effects in time periods are used numerical methods that deal with flow of compressible fluid: FTCS, Lax-Friedrichs and Lax-Wendroff method. The numerical results are confronted with the experiment. During the experiment simulation the method considers speed of sound in liquid like a function of pressure. This diploma thesis lays partial principles for finding elastic constants for describing dynamic characteristics of elastic pipes by measuring the pressure pulsations.
Analysis of measured signals from cavitation experiments
Asszonyi, Ondřej ; Habán, Vladimír (referee) ; Rudolf, Pavel (advisor)
This thesis focuses on problem with detection of cavitation in hydraulic systems and devices. Thesis works with data from cavitation tunnel experiment, where cavitation appeared on blade. It founds out if time records and their frequency spectrum is dependent on operating conditions. Data are examined by various statistic methods. All of that is then used in method called neural network.

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