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The Evaluation of RTK method precision
Horák, Aleš ; Volařík, Tomáš (referee) ; Kuruc, Michal (advisor)
The aim of this diploma thesis was to evaluate a precision of spatial position of chosen services from Czepos and TopNET providers. The chosen services were virtual reference station generated by MAC concept from Czepos provider and virtual reference station NVR3 from TopNET provider. Testing measurement was measured by RTK method with GNSS instrument from Leica System 1200. There were measured long-standing observations which lasts 24 hours and short observations which lasts five and twenty seconds. The short observations were measured at five points in area of Brno. Result of the thesis is comparisons of precisions in position and height.
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Phase Changes on Heat Exchanger Surfaces with Hollow Fibers
Kůdelová, Tereza ; Horák, Aleš (referee) ; Dohnal, Mirko (referee) ; Raudenský, Miroslav (advisor)
The thesis focuses on the polymer hollow fibres heat exchangers. The main object of the research is the formation and process of condensation on the outer surface of fibres and the effect of phase change on the heat transfer. The study deals with the influence of the geometry of the heat exchnager on the heat transfer and the condensation process. Fatigue tests of polymeric hollow fibres exchangers are also part of the work. The work provides an overview of the possible use of such heat exchangers in industrial applications associated with condensation.
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Leadership – Manager Skills Analysis
Horák, Aleš ; Hubinková,, Zuzana (referee) ; Franková, Emilie (advisor)
This diploma thesis focus on comparison of the management of 1st half of 20th century with present days. The main goal of thesis is to analyze a lurid career of Czech top manager Domink Cipera, his operation methods and usage of innovative management procedures (that were used during his business and politics career), based on the available published sources. Thesis is in addition comparing Cipera’s management style in context of that era with current acting managers and is concerning with Cipera’s profession heritage and his influence to modern management. Practical section of the thesis is dealing with sociological research on the sample of current acting managers. Design section is describing potential improvement in area of systematical managerial education of managers and executive project employees in the concrete company.
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Airplane Cooling System Optimization
Lajza, Ondřej ; Fiľakovský, Karol (referee) ; Horák, Aleš (referee) ; Píštěk, Antonín (advisor)
Dissertation thesis is focused on the aircraft cooling system optimization. The knowledge of the pressure loss is necessity for design of an optimal system. In the beginning of the thesis, the different designs of piston engine cooling systems are described for both aircrafts and automobiles. Other sections outline the determination of the coolers characteristics and describe the different test sections applicable for the characteristics measurement. The test section built at the Institute of the aerospace engineering is described as well. Practical part of the thesis describes the calibration of the test section. The measurements of the specific coolers were compared with the CFD simulation of two models - the simplified cooler model and cooler element model. Additionally, the measurements were compared with results obtained at specialized coolers testing facility.
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A car prototype manufacture using modern methods and CAD/CAM
Horák, Aleš ; Zouhar, Jan (referee) ; Sedlák, Josef (advisor)
The project developed under the engineering studies, solves the problem of production of a prototype car using modern technology, reverse engineering and CAD / CAM. Based on the literary study of the issue, was designed process of digitization of the physical model of car, including the treatment and processing of data. Follow-up step was to verify the production of the additive rapid prototyping technology - FDM method. Verification of the results was performed on a vertical milling cantilever FV 25 CNC with control system Heidenhain iTNC 530 using a cutting strategies by PowerMILL CAM software. At the end of the resulting models edit as necessary.
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Chassis and Engines Development of WRC Cars
Horák, Aleš ; Svída, David (referee) ; Dundálek, Radim (advisor)
The bachelor´s thesis elaborated in frame of bachelor studies branch B2341 deals the analyse deal with problems sports model intended on automobile contests rally. Gradually is here described undercart and motor competitive specials WRC. Near of each of part is explained keystone, usage and gradual evolution with reference to rules FIA.
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Design of Experiment for Inverse Heat Transfer Problem
Horák, Aleš ; Pavliska,, Martin (referee) ; Štětina, Josef (referee) ; Raudenský, Miroslav (advisor)
this thesis complex inverse heat transfer problem, which is focused on optimal design of experiment, is studied. There are many fields and applications in technical practice, where inverse tasks are or can be applied. On first place main attention is focused on industrial metallurgical processes such as cooling of continues casting, hydraulic descaling or hot rolling. Inverse problems are in general used to calculate boundary conditions of differential equations and in this field are used to find out Heat Transfer Coefficient (HTC). Knowledge of numerical approximation of precise boundary conditions is nowadays essential. It allows for example design of optimized hot rolling mill cooling focused on material properties and final product quality. Sequential Beck’s approach and optimization method is used in this work to solve inverse heat transfer problems. Special experimental test bench measuring heat transfer intensity was developed and built to full fill specific requirements and required accuracy. There were four different types of thermal sensor applied and studied. Those sensors are in usage in Heat Transfer and Fluid Flow laboratory (Heatlab) at various experimental test benches. Each specific sensor was tailored in Heat Transfer and Fluid Flow Laboratory to specific metallurgical application. Fist type of sensor was designed to simulate cooling during continuous casting. Second sensor is used for experiments simulate hot rolling mill cooling, while third sensor is designated for experiments with fast moving hot rolled products. Last sensor is similar to sensor type one, but thermocouple is located parallel to cooled surface. Experimental part of this study covers series of measurements to investigate Heat Transfer Coefficient (HTC) for various types of coolant, cooling mixtures and spray parameters. Results discovered in this study were compared with published scientific articles, and widely extend the knowledge of cooling efficiency for commonly used
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Polymeric Hollow Fiber Heat Exchanger Design
Astrouski, Ilya ; Dohnal, Mirko (referee) ; Horák, Aleš (referee) ; Raudenský, Miroslav (advisor)
This Ph.D. thesis is focused on theory and experimental investigations developing of new knowledge about polymeric hollow fiber heat exchanger (PHFHE). The state-of-the-art study of plastic heat exchangers shows that their usage is limited by several niches where their advantages significantly dominates, or where the use of non-plastic competitors is not impossible. On the other hand, plastic heat exchangers (and PHFHEs in particular) are devices of increasing interest. It is shown that use of small tubes (fibers) allows PHFHEs to be more competitive than conventional plastic heat exchangers. Small hydraulic diameter of a fiber causes high heat transfer coefficients, reduces thermal resistance of plastic wall and allows it to create light and compact design. Detailed study of fluid flow and heat transfer inside the hollow fiber showed that conventional approaches for single-phase laminar flow can be utilized. Poiseuille number equal to 64 and Nussel number about 4 are recommended to be used to predict pressure drops and heat transfer coefficient, respectively. Additional attention should be paid to careful determination of fiber diameter and liquid properties (viscosity). Scaling effects, such as axial heat conduction, thermal entrance region and viscous dissipation can be neglected. The study of outside heat transfer showed that heat transfer on fiber bunches are intense and are competitive to contemporary compact finned-tube heat exchangers. The Grimson approach showed clear correlation with experimental results and, thus is recommended to predict heat transfer coefficients on fiber bunches. Two types of fouling (particulate- and biofouling) of outer fiber surface were experimentally studied. It was found that particulate fouling by titanium oxide particles is not intense and deposits can be removed relatively easy. However, fouling is much more intense when it is associated with biofouling caused by wastewater. In this case, smooth and low-adhesive surface of plastic is not sufficient precaution to prevent deposit formation.
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