National Repository of Grey Literature 75 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Transparent packing for optical experiments in Rotating packed beds
Hájek, Jiří ; Elcner, Jakub (referee) ; Malý, Milan (advisor)
Given the amount of energy and industrial processes that produce carbon dioxide, it is necessary to reduce the amount of CO2 emitted into the atmosphere. One option is to capture and store the carbon dioxide produced, called CCS (Carbon Capture and Storage). For effective capture, a rotating packed bed absorber can be used, which works on a similar principle to a static absorption column, but the driving force of the liquid is not gravity but centrifugal force. This allows the device to be very compact in size. To optimise the absorption process, it is necessary to analyse the nature of the flow inside the absorber. This work focuses on the design and testing of a unique packed bed with stainless steel wire filling and transparent plexiglass support parts for optical analysis of the internal flow. Using a high-speed camera, the nature of the fluid flow was recorded under different operating modes. The changed parameters were the operating speed, which ranged from 300 to 1,800 rpm, and the velocity of the fluid flow, ranging from 1.25 to 11.5 m/s. When evaluating the nature of the flow, attention was paid mainly to the inner part of the packing fill, where the droplet size and velocity change the most. However, the assessment of the flow across the entire packing was also evaluated. Recommendations for the choice of operating modes, evaluation of droplet size and, finally, the empirical correlation for the calculation of the absolute liquid velocity at the inner part of the packing is also discussed.
Modeling of process and power equipment fouling by solid pollutants
Strouhal, Jiří ; Turek, Vojtěch (referee) ; Hájek, Jiří (referee) ; Jegla, Zdeněk (advisor)
Modelling of particulate fouling based on Computational Fluid Dynamics enables to detect a risk of deposit development and to propose improvements in operating conditions and equipment design. The work focuses on the transport and sticking of solid particles. The size of the particles lies in the range from several up to dozens of m. The conditions correspond to the deposition of particles with a negligible liquid fraction and the deposition occurs due to particle deformation, gravity, adhesion, wall surface roughness, deposit deformation and dynamic friction. An emphasis is put on the selection of a suitable sticking model from the group of critical velocity models, which aside from the local conditions and the particle properties account for the impaction velocity. Sensitivity studies on the model settings were conducted to assess the significance of the model parameters and the included phenomena. The simulations were conducted on the case of an experimental facility for solid fuels combustion. Obtained results were compared to observed deposits.
Principles of open and closed kinematic chains and their usage in rehabilitation
Hájek, Jiří ; Kučerová, Klára (advisor) ; Kurková, Simona (referee)
Bakalářská práce Princip otevřených a uzavřených kinematických řetězců a jeho využití v praxi 7 Abstract The terms open (OKC) and closed (CKC) kinematic (kinetic - OKIC and CKIC) chain are very often used in physiotherapy. However, this view has a problem in defining the chains. In theoretical part, we focused on definitions according to individual authors, publications and studies that mention the terms. Because the terms OKC and CKC are perceived very differently in the literature and many authors have adapted them to their image. Based on the acquired knowledge, we find the view of the kinematic chains to be insufficient, inconsistent and thus confusing. In the work, we focused on processing as many resources as possible with the given issue. In the practical part, we used a structured questionnaire focused on therapists in clinical practice. We asked how they use the terms OKC and CKC (resp. OKIC and CKIC) and what experience do they have with the terms in their clinical practice. The aim was to find out: to description of which situations are these terms used for and how the terms are used in different kinesiological situations. To what extent are they used in accordance with the definitions or to what extent they differ from them. Based on the results of the questionnaire and the mentioned literature...
Fine particles emitted from a heat source into the indoor environment
Hájek, Jiří ; Köbölová, Klaudia (referee) ; Pospíšil, Jiří (advisor)
This bachelor's thesis deals with fine particles emitted to indoor space during combustion in fireplace stowes. The beginning of work is focused on the description of biomass and its combustion. In the following part the pollutants, which are produced by combustion of bio-mass are mentioned, and last but not least is attention focused on current air quality in Czech Republic methods of measure of solid pollutants and measuring equipment. Calculation of concentration is closely described in the experimental part, and then the data, which was measured on different modes of operations of fireplace stowes, is presented.
Development of computational tool for engineering
Komiš, Jan ; Hájek, Jiří (referee) ; Vondál, Jiří (advisor)
The thesis aims to provide insight into the use of Python in engineering calculations. The thesis has been divided into a theoretical and practical part. The theoretical part introduces Python and its possible uses in the field of engineering. The second section of the theoretical part describes key choices of study resources and provides instructions on how to set up Python from the perspective of a common user. The final part of the thesis deals with the choice of appropriate libraries (SciPy, NumPy, Cantera, etc.) and shows how these can be used practically in specific tasks from the fields of thermomechanics and hydromechanics.
Modeling of nonlinear diffusion
Oyekan, Oluwadamilola Adeniyi ; Hájek, Jiří (referee) ; Franců, Jan (advisor)
In this thesis, we study the nonlinear diffusion equation especially Porous Medium Equation (PME). u_t= \Delta(u^m) + f(u), Parameter m>1 in the case of slow diffusion, m=1 means linear model and $0
Modelling of water distributor in a steam conditioning valve
Polášek, Radek ; Juřena, Tomáš (referee) ; Hájek, Jiří (advisor)
The purpose of the thesis is to create a model for an analysis of a steam conditioning valve whose function is to reduce the temperature of the steam using a spray water system. First of all, simulation of the fluid flow and heat transfer is done using CFD analysis. Then the results are used for thermal stress calculation.
CFD modelling of pipe flow mixing of liquids
Pavlíček, David ; Hájek, Jiří (referee) ; Juřena, Tomáš (advisor)
This work is focused on computational modelling of mixing fluids in pipeline with static mixers. Main objective is to analyze several selected static mixers in a particular industrial application, namely dosing of the aluminium sulphate solution in the clarification process for potable water treatment. The analysis focuses on the degree of mixedness and pressure loss of individual mixers. Further, the aim of this work is to process the search of available types of static mixers. The benefit of this work is at least an effort to motivate the reader to deeper understanding of the mixing fluids, especially by static mixers.

National Repository of Grey Literature : 75 records found   1 - 10nextend  jump to record:
See also: similar author names
45 HÁJEK, Jan
10 Hájek, Jakub
45 Hájek, Jan
2 Hájek, Jaromír
12 Hájek, Jaroslav
1 Hájek, Jindřich
20 Hájek, Jiří
1 Hájek, Jonáš
4 Hájek, Josef
1 Hájek, Jáchym
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