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Computational analysis of fluid flow in a tumble dryer
Dohnal, Miloslav ; Juřena, Tomáš (referee) ; Hájek, Jiří (advisor)
The aim of this work is to create a computational model of radial industrial tumble dryers, to calculate and identify the amount of air that flows through the inside of the drum itself. The calculation will be performed via computational fluid dynamics (CFD). Furthermore, compile transient balance model of mentioned dryers. Perform simulation balance model and compare the results of simulations with experimental measurements. By comparing the experimental data and simulation to determine the degrees of freedom of balance model and evaluate their impact on the assembled transient model. For a better understanding of the drying process, there is constructed a system of differential equations describing heat and moisture within the material being dried on a simple model. In the section devoted to the computational analysis of fluid flow is analyzed existing geometry of the drum, which has a major impact on the flow of air inside the drum itself. Following describes how to simplify its complex geometry entering the computational fluid dynamics. Then, there is carried out a simulation of fluid flow inside the tumble dryers using MRF and Sliding Mesh models. Finally, there is an analysis of the data obtained and determined the average amount of air flowing through the drum itself. On the contrary, the aim of the work is not to create another text tool for students engaged in CFD theme.
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Analysis of Flow Distribution in Systems with Dense Tube Bundles
Babička Fialová, Dominika ; Dohnal, Miloslav (referee) ; Turek, Vojtěch (advisor)
Considering heat transfer equipment with dense tube bundles, it is essential to ensure as uniform a fluid distribution into the tubes as possible in order to prevent various operating problems. This bachelor’s thesis therefore focuses on tube-side flow analysis in such equipment. CFD simulations were carried out using a diverse set of flow systems with outflow into a constant-pressure environment. The respective tube bundle geometries differed in densities and sizes, arrangements of the tubes, and tube diameters. Air was used as the working fluid in the majority of the cases, however, some of the simulations were also carried out with water. Data obtained from evaluations in the fluid flow modelling software ANSYS Fluent were further analysed and the influence of the mentioned differentiating parameters on flow distribution non-uniformity and pressure drop was investigated. According to the regression model, the dependence of flow distribution non-uniformity on density and size of the bundle and on mass flow rate per unit outflow area cannot be rejected with the standard significance level. As for pressure drop, the only parameter that was not rejected was mass flow rate per unit outflow area.
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2-D external aerodynamics of an unusual shaped body
Mohyla, Daniel ; Gal, Pavel (referee) ; Dohnal, Miloslav (advisor)
This bachelor thesis is focused on analysis of flow over a cylindrical rod in 2-D space by using computational fluid dynamics (CFD) with turbulence models k- SST and k- SSTSAS. First part of this thesis is meant to be an introduction to the topic of extrernal flow and CFD. In this part the topics of flow separation, turblence modeling and various related models are discussed. Second part deals with the description of simulation case inside of open source CFD software called OpenFOAM and the obtained results. In last part the disccusion about results is carried out and results are compared.
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Design optimization of water-cooled thermocouple probe
Dohnal, Miloslav ; Vondál, Jiří (referee) ; Hájek, Jiří (advisor)
The object of this bachelor’s thesis is to create a computational model of an existing (basic) structure water-cooled thermocouple probe, to calculate and evaluate the quality of existing cooling probe and to propose possible design modifications to improve the cooling effect of the probe tip. Verify and evaluate design modifications by further calculation. The calculation will be carried out using computational fluid dynamics (CFD method). On the contrary, the aim of this work is not to create another text tool for students dealing with CFD topics. The first part describes the meaning and history of the CFD methods, then mentions the work on the principle of thermocouple probes and its application in practice. The second part of the work is devoted to problem solving. It describes the reason for the introduction of model situations when calculating the cooling effect of thermocouple probes and calculation indicates what type of flow occurs inside the thermocouple probe. It further describes the results of calculations for several approximations gradually increasing accuracy of the resulting solution of the problem and assessing the quality of cooling in the probe tip current (basic) structure. The final part deals with design changes for better cooling effect especially in the probe tip, which is verified by further calculation as well.
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Calculation of steam pipeline
Majer, Jan ; Dohnal, Miloslav (referee) ; Nekvasil, Richard (advisor)
This thesis describes issues related to design and structural analysis of steam pipeline. Analysis are done by using two different software program – AutoPIPE and Ansys. Issues related to pipeline support system and thermal expansion are solved by using AutoPIPE. Structural analysis results are evaluated in accordance with ČSN EN 13 480 code.
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Flow in a bypass of a waterfeed valve
Waloszek, Jan ; Dohnal, Miloslav (referee) ; Juřena, Tomáš (advisor)
Fluid flow in pipes and fittings has a significant meaning in many sectors of industrial applications and thus it is important to reduce hydraulic ressistance in order to reduce pressure loses and ensure better efficiency of the system. In this thesis flow through two types of fitting is solved, using computer simulation. Empirical equations are used to verify results and to set the computer model right. This thesis formulates several conclusions in relation to k- turbulence model and accuracy of the results related to discretisation of the mesh.
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Design check calculation of piping according to ASME B31.3
Dohnal, Milan ; Dohnal, Miloslav (referee) ; Létal, Tomáš (advisor)
The thesis is focused on check stress analysis of an already constructed piping system, which constitutes a key element in the transport of process fluids, especially liquids. Properly functioning piping is required to withstand the anticipated loads, both in the test and in the operating conditions. For the resistance assessment, ASME codes were used, especially ASME B31.3, which is widely used in the industry worldwide.
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Virtual modelling of computional domain for CFD simulations
Volek, Matěj ; Naď, Martin (referee) ; Dohnal, Miloslav (advisor)
This thesis is devoted to open-source software for meshing in CFD simulations. In the opening chapter, there is introduced the computational modeling of fluid, briefly described governing equations and an introduction to the discretization of computational domain. The second chapter deals with the available mesh software. The programs are described in this chapter from the perspective of the user interface, the ability to create meshes, etc. The last chapter, there is a comparison of two selected programs on a real problem. In both programs was created a mesh which was calculated in the software Fluent. Then the calculation results are compared.
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Comparison of flange connections design
Hrbáček, Jan ; Dohnal, Miloslav (referee) ; Buzík, Jiří (advisor)
Flange connections are type of connections frequently used in industry. There are hight claims for their dimensioning, strength and tightness. The proper and exact design can be made by calculation or by choice of standardized components (flanges, bolts, nuts etc.) accordig to requirements established by standart. This Bachelor´s thesis occupies itself with qualitative comparison of proposals for the strength design of flanged conections according to ČSN EN 13445, AD 2000 Merkblatt and ASME Code standarts. The programming language called Python is used in this Bachelor´s thesis.
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Flow in a bypass of a waterfeed valve
Waloszek, Jan ; Dohnal, Miloslav (referee) ; Juřena, Tomáš (advisor)
Fluid flow in pipes and fittings has a significant meaning in many sectors of industrial applications and thus it is important to reduce hydraulic ressistance in order to reduce pressure loses and ensure better efficiency of the system. In this thesis flow through two types of fitting is solved, using computer simulation. Empirical equations are used to verify results and to set the computer model right. This thesis formulates several conclusions in relation to k- turbulence model and accuracy of the results related to discretisation of the mesh.
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