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Optimization of air transport in the fan chamber with a free impeller
Cakl, Dominik ; Bašta, Jiří (referee) ; Cifrinec, Ivan (referee) ; Rubina, Aleš (advisor)
The work deals with the improvement of the hydraulic properties of air transport in fan chambers with free impeller wheels, which are equipped in every larger central air handling system. Every larger central air handling system is equipped with a fresh air intake that transports the air into a fan chamber, which contains a free-wheel fan that provides air transport and provides kinetic energy to the air stream. From the fan chamber, the air is further transported by the air handling system to the individual distribution elements. Similiary, the extraction of polluted air is solved through the fan chamber. The turbulent flow of air at the outlet of the impeller causes a pressure loss in the discharge chamber of the air handling unit, as the air is transported in pulses according to the slip of the blades. In practice, fans with smaller performance parameters measured in laboratories under ideal boundary conditions are installed in air handling units, which do not solve the problem of the difference in real traffic pressure between the supply and exhaust air ducts, with the result that the installed fans in the real fan box do not reach the parameters specified by the manufacturer. Reduction the pressure losses in fan chambers is correlated with the reduction of energy consumption of equipment ensuring air transport in the context of sustainable construction. Based on the development of aerodynamic efficiency of fans and European legislation, the current trend of a significant reduction in energy consumption was described, among other things, for equipment providing air transport, through repairs, reuse, repurposing and recycling of used materials, and through extending the life of products and buildings. Furthermore, three research principles and methods of improving the efficiency of equipment in order to reduce the energy demand of equipment ensuring air transport are presented, the authors of which approach the research numerically and experimentally. The goal of the original technical solutions presented in this work is to present a development that optimizes the pressure losses of a fan chamber with a free impeller. The first solution describes the principle of lead-in plates, where the goal is to help the air stream eliminate the negative effects of swirling and facilitate the outflow of air from the fan chamber by means of a smooth slide along an inclined surface, which reduces the specific power of the fan, under the given marginal conditions, by up to 5.9 %. The essence of the second innovative technical solution is to present a free impeller, which is based on the connection of two rows of curved blades of concave and convex shape, which serves to optimize the pressure loss of the fan chamber with a free impeller, which produces smaller, more uniform, mutually interacting currents that help the flow of air to more smoothly change the direction of swirling in the fan chamber and which found practically no value for the specific measured boundary conditions. The essence of the third innovative technical solution is the introduction of modern production of products from "sustainable" materials with the help of 3D printing, in the form of a free impeller for fans with a free impeller. The results of geometric copies of free impellers made of lighter material reflect that there was a reduction in the average specific power of the fan by up to 4.4 %, while at the same time there was a reduction in the total sound level.
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Device for measuring tensile tests of 3D printed materials
Besta, Pavel ; Binar, Tomáš (referee) ; Vyroubal, Petr (advisor)
This thesis deals with the problematics of 3D printed materials, specifically with FDM and SLA methods of 3D printing and their reliability when it comes to tensile strength. After comes introduction of materials used in FDM and SLA 3D printing and description of how certain printing parameters affect the final mechanical properties of 3D printed parts. Last theoretical part of this thesis deals with tensile tests and the means of getting deformation curves out of these tests. In the practical part of this thesis is described the design of electronics for a device for measuring tensile tests provided by the institute of electrotechnology. Part of this thesis is also a detailed guide on how to perform and evaluate tensile tests and measured mechanical properties of some materials.
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Deposition of particles released by 3D printing
Niesner, Lukáš ; Elcner, Jakub (referee) ; Bělka, Miloslav (advisor)
This thesis deals with the measurement of particles emitted by a 3D printer in a domestic environment and the subsequent CFD simulation of the deposition of these particles in a realistic model of the human airway. As a result of the work, the total and partial deposition of nanoparticles in the airway model can help to better understand the health risks.
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Tabletop acrylic paint shaker
Vostradovský, Tomáš ; Žáček, Jiří (referee) ; Klapka, Milan (advisor)
This bachelor thesis deals with construction of a model paint desktop shaker for small containers. Included is an overview of solutions available on the market, creation of design proposals, selection of a suitable solution and its finalization into production documentation. Following is production of a prototype and verification of its functionality.
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Data Concentrator of 3D Printer's Sensors and Devices
Vaculík, Samuel ; Rusnák, František (referee) ; Arm, Jakub (advisor)
The bachelor thesis consists of designing and implementing a system for collecting data related to 3D printing. The aim is to define the variables suitable for measurement, select sensors for the measurements and implement them on the printer. The next point is the design and implementation of data acquisition from the printing firmware Klipper for collecting print data. Then the task is to implement the software for processing data from the individual measurement sources, including data flow analysis in the system.
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Production of a replica of the switch cover using the investment casting method
Klátil, Ondřej ; Kaněra, Miloš (referee) ; Jelínek, Radim (advisor)
The work is focused on the production of a replica switch cover for the ČZ 250/471 motorcycle from 1974. The theoretical part of thesis includes a review of the production of permanent and expendable patterns, mold making, various casting methods, additive technologies categorized under rapid prototyping methods, and a description of scanning methods. In the experimental part, the informations from the theoretical part are verified through the experiment of producing the switch cover replica. The original part was first scanned, then the scan was edited and converted into a solid model, which was then printed on an FDM printer as a expendable pattern for the investment casting method using shell molds. These castings were then evaluated against the originals. At the end of the experiment, surface defects were found, the causes of which could not be definitively explained. Subsequently, various production methods were outlined for specific ranges according to the number of products.
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Autonomous unit for growing indoor plants
Pluskal, Petr ; Appel, Martin (referee) ; Věchet, Stanislav (advisor)
This bachelor's thesis focuses on the design and assembly of an autonomous cultivation system for indoor plants in households. Autonomous and efficient cultivation of indoor plants poses a challenge for many home gardeners due to the constant need for care and attention. The thesis discusses the basic requirements and conditions for quality plant growth, such as temperature, soil moisture, air humidity, and lighting. Suitable sensors for measuring these key parameters are selected, and the thesis addresses their integration and implementation into the entire system. The unit's construction is realised using 3D printing, analysing its properties, particularly regarding waterproofing and contact with organic elements. These insights inform the printing of individual parts of the system. Combining printed parts, sensors, and a programmed Arduino system creates a functional autonomous plant cultivation system. Monitored data are directly utilised in the system's code, statistically processed, and visualised using the ThinkSpeak service. Experimental results demonstrate the successful functionality of the system in maintaining optimal conditions for plant growth and development. This autonomous cultivation system represents an innovative solution for simplifying the care of indoor plants in a home environment.
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3D printing of a non-dismantling assembly
Halíř, Jan ; Drbal, Martin (referee) ; Kalivoda, Milan (advisor)
The bachelor's thesis deals with 3D printing of prototype non-disassemble assemblies. In the theoretical part, the individual most used printing technologies, the types of plastic and metal materials used, printers, 3D scanners, and their use in medicine, construction and engineering was described. In the practical part, FDM technology was used to print the ball joint, the french key, and the rolling bearing, the functionality of which were tested. In the last part, the results of the prints were evaluated based on the selected parameters and material about their functionality.
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Optimization of infill selection with an emphasis on maximum dynamic resistance
Konvalina, Michal ; Svoboda, Petr (referee) ; Jopek, Miroslav (advisor)
The thesis deals with the study of the effect of different wall thicknesses of 3D printed infill patterns at constant cross-sectional area on their final properties under static and dynamic loading. Based on literature study, two experimental methods are chosen. The quasi-static test and the Taylor anvil test. For the experiment, square and hexagonal grid specimens are printed using FDM technology from PLA material. Quasi-static test is used to measure the static properties such as maximum compressive strength, yield stress, modulus of elasticity and to derive material model of Johnson-Cook. The dynamic impact test TAT is used to evaluate different types of patterns at high impact velocities. In ANSYS, the specimens that resisted the highest impact velocities in TAT are simulated and strain rate sensitivity parameter is optimized for the specific velocity. The highest dynamic resistance was achieved by a square infill pattern with wall thickness of 0,4 mm at an impact velocity of 37 ms-1.
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Use of 3D printed models for Replicast technology
Komenda, Lukáš ; Štěpán, Radim (referee) ; Bořil, Petr (advisor)
This bachelor's thesis is focused on the possibility of casting a 3D printed model using Replicast® technology. The theoretical part provides an overview of the application of rapid prototyping technology in foundry industry and the advantages of the Replicast® process. The practical part is focused on the production of a 3D printed model, the creation of a shell, and subsequent casting. In the conclusion of the thesis, the individual results are compared and the best approach is evaluated.
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