National Repository of Grey Literature 10 records found  Search took 0.02 seconds. 
Measurement of spray characteristics using optical measurement methods
Ďurdina, Lukáš ; Otáhal, Jan (referee) ; Jedelský, Jan (advisor)
Diplomová práce se zabývá měřením charakteristik sprejů dvou tlakových vířivých trysek pro spalovací komoru malého turbínového motoru na zkušebním stavu za studena pomocí metod Particle Image Velocimetry (PIV) a fázové Dopplerovské anemometrie (PDA). Cílem měření bylo stanovit a porovnat charakteristiky sprejů obou trysek. Výsledky měření mají objasnit rozdílnost chování trysek za provozu a možný dopad na proces spalování. Úvodní teoretická část pojednává o základních fyzikálních principech atomizace kapalin, konstrukci a oblasti uplatnění tlakových vířivých trysek a o principech laserových diagnostických metod použitých při experimentálním měření. Nasledující část popisuje návrh a montáž zkušební trati a dalších zařízení navržených pro experimentální měření v této práci. Experimentální část se zabývá nastavením parametrů měřícího systému a zpracováním dat. Výsledky měření zahrnují vektorová rychlostní pole, axiální rychlostní profily a distribuce velikosti kapek pro různé provozní podmínky obou trysek.
Design of a drying device for wood-processing industry
Vach, Tomáš ; Hrázský, Jaroslav (referee) ; Otáhal, Jan (advisor)
The thesis considers a stabilization of temperature of a wood fiber during production of medium close fibre boards MDF in a wood-processing industry. The original purpose to solve energetic optimalization of a kiln dryer has become a serious problem. It turned out that production suffers with a big heat loss which results in big heat loss gained during a kiln drying. Primary aim of this thesis is an examination of a cooling effect of environment on chosen parts of a production line and suggestion of acceptable proceeding to minimize heat loss and to rise temperature of the wood fiber to required temperature. Solution is aimed on the section of a production line between drying equipment and press. First part of the thesis introduces technology of production of fibre boards, introduction to heat transfer problems and also basics of computer modeling of heat flow and transfer using CFD simulation. The next part includes an evaluation of the heat loss of chosen parts of the production line in a current working condition and its comparison with computer simulations. Verification of accuracy of the results while using both approaches to solution is a first step to the improvement of the current situation. It is possible to use the verified calculation model for the following solution of effects on convective and radiation heating of a wood fiber layer. An important factor in the last period of a calculation is a real temperature of the fiber board-mat at the entrance to a press. The higher entering temperature in a set temperature range is reached, the lower time needed for pressing will be and simultaneously the whole industrial process will be cut short. The solution of a problem leads to an achievement of an energy saving and should become a solid basis from which it would be possible to evaluate an improvement of production of MDF boards. The conclusion of the thesis includes an analysis of findings which refers to a heating of wood fiber and it’s effectiveness for a practical use.
Potential of biomass utilization in the Czech Republic
Klímová, Jana ; Otáhal, Jan (referee) ; Košner, Jan (advisor)
Main task of this bachelor work is to focus on splitting and usage of alternative, renewable energy source – biomass, as a source of thermal and combined electrical energy and to review possibility of increasing of consumption of this source on territory of the Czech Republic. In this work certain kinds of biomass, potential and possibility of it’s usage suggestion for utilization, according to Action plan for biomass and main ways of it’s development will be presented.
Local Ventilation
Bilík, Martin ; Otáhal, Jan (referee) ; Krejčí, Vladimír (advisor)
This bachelor thesis deals with local ventilation, especially a variant of the local exhausting. At the start of work shall indicate the reasons why it is ventilation very important. There are listed some requirements for ventilation of technical and legislative terms. Ventilation systems are analyzed by several criteria in the next part. The next chapter of this work is devoted to systems and methods of local ventilation. In one chapter is made and a description of the distribution parts of the ventilation system. The last chapter deals with designing and using exhaust adapters. There is also made comparison of their parameters, which represent the operating costs associated with using these adapters.
Drying-Plant for smoked meat products
Čermák, Lubomír ; Otáhal, Jan (referee) ; Krejčí, Vladimír (advisor)
The thesis deals with essential requirements to dry and cure meat products using drying chambers. It covers the basic salami classification, the relevant parameters applicable to the drying chambers as well as the hygiene and sanitation and their influence on productivity. The drying technology is particularly emphasized. Brief information is provided regarding the fermentation and curing processes.
Measurement of spray characteristics using optical measurement methods
Ďurdina, Lukáš ; Otáhal, Jan (referee) ; Jedelský, Jan (advisor)
Diplomová práce se zabývá měřením charakteristik sprejů dvou tlakových vířivých trysek pro spalovací komoru malého turbínového motoru na zkušebním stavu za studena pomocí metod Particle Image Velocimetry (PIV) a fázové Dopplerovské anemometrie (PDA). Cílem měření bylo stanovit a porovnat charakteristiky sprejů obou trysek. Výsledky měření mají objasnit rozdílnost chování trysek za provozu a možný dopad na proces spalování. Úvodní teoretická část pojednává o základních fyzikálních principech atomizace kapalin, konstrukci a oblasti uplatnění tlakových vířivých trysek a o principech laserových diagnostických metod použitých při experimentálním měření. Nasledující část popisuje návrh a montáž zkušební trati a dalších zařízení navržených pro experimentální měření v této práci. Experimentální část se zabývá nastavením parametrů měřícího systému a zpracováním dat. Výsledky měření zahrnují vektorová rychlostní pole, axiální rychlostní profily a distribuce velikosti kapek pro různé provozní podmínky obou trysek.
Design of a drying device for wood-processing industry
Vach, Tomáš ; Hrázský, Jaroslav (referee) ; Otáhal, Jan (advisor)
The thesis considers a stabilization of temperature of a wood fiber during production of medium close fibre boards MDF in a wood-processing industry. The original purpose to solve energetic optimalization of a kiln dryer has become a serious problem. It turned out that production suffers with a big heat loss which results in big heat loss gained during a kiln drying. Primary aim of this thesis is an examination of a cooling effect of environment on chosen parts of a production line and suggestion of acceptable proceeding to minimize heat loss and to rise temperature of the wood fiber to required temperature. Solution is aimed on the section of a production line between drying equipment and press. First part of the thesis introduces technology of production of fibre boards, introduction to heat transfer problems and also basics of computer modeling of heat flow and transfer using CFD simulation. The next part includes an evaluation of the heat loss of chosen parts of the production line in a current working condition and its comparison with computer simulations. Verification of accuracy of the results while using both approaches to solution is a first step to the improvement of the current situation. It is possible to use the verified calculation model for the following solution of effects on convective and radiation heating of a wood fiber layer. An important factor in the last period of a calculation is a real temperature of the fiber board-mat at the entrance to a press. The higher entering temperature in a set temperature range is reached, the lower time needed for pressing will be and simultaneously the whole industrial process will be cut short. The solution of a problem leads to an achievement of an energy saving and should become a solid basis from which it would be possible to evaluate an improvement of production of MDF boards. The conclusion of the thesis includes an analysis of findings which refers to a heating of wood fiber and it’s effectiveness for a practical use.
Local Ventilation
Bilík, Martin ; Otáhal, Jan (referee) ; Krejčí, Vladimír (advisor)
This bachelor thesis deals with local ventilation, especially a variant of the local exhausting. At the start of work shall indicate the reasons why it is ventilation very important. There are listed some requirements for ventilation of technical and legislative terms. Ventilation systems are analyzed by several criteria in the next part. The next chapter of this work is devoted to systems and methods of local ventilation. In one chapter is made and a description of the distribution parts of the ventilation system. The last chapter deals with designing and using exhaust adapters. There is also made comparison of their parameters, which represent the operating costs associated with using these adapters.
Drying-Plant for smoked meat products
Čermák, Lubomír ; Otáhal, Jan (referee) ; Krejčí, Vladimír (advisor)
The thesis deals with essential requirements to dry and cure meat products using drying chambers. It covers the basic salami classification, the relevant parameters applicable to the drying chambers as well as the hygiene and sanitation and their influence on productivity. The drying technology is particularly emphasized. Brief information is provided regarding the fermentation and curing processes.
Potential of biomass utilization in the Czech Republic
Klímová, Jana ; Otáhal, Jan (referee) ; Košner, Jan (advisor)
Main task of this bachelor work is to focus on splitting and usage of alternative, renewable energy source – biomass, as a source of thermal and combined electrical energy and to review possibility of increasing of consumption of this source on territory of the Czech Republic. In this work certain kinds of biomass, potential and possibility of it’s usage suggestion for utilization, according to Action plan for biomass and main ways of it’s development will be presented.

See also: similar author names
6 Otáhal, Jiří
2 Otáhal, Josef
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