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Výroba držáku objemovým tvářením / Production of holder by solid formingŠpaček, Antonín January 2008 (has links)
The diploma thesis deals with suggestion of low alloy 14220.0, produced by solid forming. This suggestion is based on the size of series that contain 100 000 pieces a year. The essay contains knowledge refering to drop forging technology and comparison with existing technologies. Two suitable variants of production were assessed, these variants are drop forging with hammers and vertical forging press. Both theories were theoretically analised in order to describe given technology. The analysis also contains calculation and suitable machine choice. Drop filling on vertical forging presses was chosen because of forging type. Furthemore forging proposition was treated including production technique. The chosen variant contains calculation, suggestion of a die, machine that was used and suggestion of flash trimming. For suggested technology was chosen vertical press LZK 3150 B. Its producer is Šmeral a.s. Brno. This project also contains technical drawings of the given component, forge, dies and phase of forging.
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Trubkový výměník pro ohřev oběhové vody. / Tube heat exchanger for heating water.Novotný, Roman January 2009 (has links)
Target of the master´ thesis is a design of heat exchanger air-water with the air flowing inside the pipes and with staggered pipe configuration, based on the engaged and chosen values. Next target is to determine heat exchanger with cross parallel flow and cross countercurrent flow of mediums, pressure drop on both sides air and water and dimensions of intake and outgoing gate on both sides air and water.
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Zápustkové kování ozubeného kola / Drop forging of gear wheelBradáč, Tomáš January 2010 (has links)
This master´s thesis submit a project of technology of production of gear wheel the way of drop forging. A part is made of steel 14 220.0 (16MnCr5). A semi-product is a stick of parametres o75 - 211 ČSN EN 10060, with a production of 130 000 pieces a year. Technological process of drop forging are worked up based on a study presented in technical literature. A forging will be working up on a vertical forging press LMZ 1600 A made in Šmeral Brno, Inc. For this option, the required technological calculation, drawing documentation and forming process simulation which is implemented by way of the software FormFEM have been carried out. Technical and economical evaluation of the component technology producing is brought in as a conclusion of the thesis.
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Výroba pastorku objemovým tvářením / Production of pinion by solid formingFic, Pavel January 2012 (has links)
In a present diploma thesis is detail study from volume hot-forming knowledge – forging. In thesis is make proposal of technologies how to produce a pinion d140 drawing nr.: DP2012 -01 and the optimatization of technology procedure with help a computer simulation. Quality of part is steel 14220. Semi-product is a bar 80 x 150 ČSN 42 5510.21. For presumtion series 160 thousand pieces and mechanical stressed working of piece is choose drop forging technology in the vertical forging press LMZ 2500, product of Šmeral Brno. From technical procedure were made necessary calculations and follow drawing documentation.
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Výroba držáku objemovým tvářením / Production of holder by solid formingŠimon, Miroslav January 2012 (has links)
The aim of this dissertation is to design an optimal technological processing of a given component by solid forming. This work includes a bibliographic study, which is the source of information for the solutions. Another important topic is the global technological processing of the given component: to begin with gear blank design until the final product. The best option seems to be the die forging on forging press in three steps. From an economical point of view, the die forging realized according to the designed technological processing appears to be the best solution.
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Doplňkový větrací systém kabiny vozu poháněný fotovoltaickým panelem / Car Cabin Aditional Ventilation System Powered by Photovoltaic PanelZdvořilý, Vítek January 2016 (has links)
The aim of the Master thesis is to design and verify the function of the system for the ventilation of parked car in the summer season with the intention to cut down the temperature peak in the cabin of the vehicle. The design of the system consists of the suitable placement of the fans and corresponding inlets and outlets for the flowing of the ventilating air. The fans are powered by a photovoltaic panel. The functionality of the system is verified by the measuring of the temperature drop in the cabin of the car. The ambient conditions for the setting of the intensity of solar radiation and of the ambient temperature have been chosen from the real measurements from TUBO station which is meteorological station of the Faculty of Civil Engineering of BUT Brno.
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Développement de modèles physiques et numériques pour la simulation aux grandes échelles des écoulements dans les tuyères supersoniques / Development of physical and numerical models for large eddy simulation of supersonic nozzlesGeorges-Picot, Alexandre 08 December 2014 (has links)
Ces travaux, initiés par le CNES (Centre National d’Etudes Spatiales) dans le cadre du programme de recherche ATAC (Aérodynamique Tuyères et Arrières-Corps), sont principalement consacrés au développement et à la validation de modèles numériques et physiques, pour la prédiction des charges latérales dans les moteurs-fusées. En effet, les systèmes propulsifs mettent en jeu des phénomènes physiques très complexes : mélange turbulent, compressibilité forte (interaction choc/turbulence, couplage de modes vorticité/entropie/acoustique), structures cohérentes et organisations tourbillonnaires dans le cas tridimensionnel, décollements massifs et instabilités à grande échelle. L’analyse de ces phénomènes nécessite le recourt à des modélisations de plus en plus fines basées sur des simulations numériques avancées. Pour faire face au coût prohibitif des simulations directes (ou simulations LES résolues) des couches limites, un nouveau modèle de paroi a été développé, en se basant sur les propriétés d’auto similarité des couches limites compressibles en tuyères supersoniques, et en utilisant des lois de renormalisation dérivées à partir d’une base de données tabulée. Ce modèle permet de prendre en compte la dynamique de l’écoulement tout en réduisant considérablement le nombre de points de calcul et le pas de temps requis pour les simulations LES. Les résultats de calcul mettent en évidence de nombreuses interactions complexes au sein de l’écoulement. En particulier, les interactions amont/aval (supersonique/subsonique),influençant fortement le décollement et la structure de chocs, à l’origine de l’apparition de pics énergétiques associés à des perturbations acoustiques conduisent à l’apparition,par rétroaction, de phénomènes d’instabilités convectives, couplées à des modes globaux dissymétriques en dynamique absolue. Ces phénomènes auto-entretenus sont synonymes d’efforts latéraux et sont représentatifs des expériences menées en laboratoire et sur bancs d’essai moteurs-fusées. En terme d’optimisation des calculs massivement parallèles, une méthode originale, appelée « Drop-Procs », a été développée dans le cadre des frontières immergées. Cette méthode, adaptée aux architectures de calculs intensifs Tier-0, permet une réduction notable du temps CPU (Central Processing Unit), allant jusqu’à 50%, et rendant ainsi ce type de simulations plus accessible à l’échelle industrielle. / This work, initiated by the CNES (Centre National d’Etudes Spatiales) in the ATAC research program (Aérodynamique Tuyères et Arrières-Corps), is devoted to the development and the validation of numerical and physical models for the prediction of side-loads in rocket engines. Indeed, propulsion systems involve complex physical phenomena : turbulent mixing, high compressibility (interaction shock / turbulence, coupling modes vorticity / entropy / acoustic), coherent structure, three-dimensional vortex organizations, massive detachment and large scale instabilities. The analysis of these phenomena requires the uses of advanced numerical simulations. To deal with the high cost of large-eddy simulations boundary layers, a new wall model, based on renormalization laws and a database, was developed. This model allows to take into account the dynamics of the flow while significantly reducing the number of calculation points and the time step required for LES simulations. Results show many complex interactions with in the flow. In particular, the upstream / downstream interactions (supersonic / subsonic), strongly influence the separation and the shock structure, causing the occurrence of energy peaks associated with acoustic disturbances and leading to the appearance of convective instability, coupled with global asymmetric modes. These self-sustained phenomena are synonymous of side-loads and are representative of laboratory experiments and rocket engine test benches. In terms of optimization of massively parallel computing, a new method, called "Drop-Procs", was developed as part of the immersed boundaries. This method is suitable for compute-intensive architectures Tier-0 and allows a significant reduction in CPU time (Central Processing Unit) consumption, up to 50%, making this type of simulation accessible for industrials.
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Samband mellan spänst och långdistanslöpning hos unga elitaktiva orienterare- en tvärsnittsstudie / Correlation between jumping performance and long distance running among young elite orienteers- a cross-sectional studyBergander, Andreas, Rask, Jesper January 2020 (has links)
Introduction: Running economy (RE) is known to be a strong indicator for performance on long distance running. RE is improved by plyometric training through an increase in stiffness in the musculotendinous system. Stretch shorten cycle (SSC) is a function in the muscle where a contraction is preceded by a stretch or an eccentric action. Orienteering is an endurance sport where RE is important for performance. Purpose: The purpose of the study was to examine whether or not there is a correlation between jumping performance and performance on long distance running in young elite orienteers 16-19 years old. Methods: 34 young elite orienteers did drop jumps (DJ) and countermovement jumps (CMJ) on an ErgoJump Bosco System contact mat. In conjunction with the jumps time on a 5 or 7 km (for girls and boys respectively) running test was collected. Pearson's correlation test was then used to determine the correlation between jumping height and running velocity. Results: The jumping height of the CMJ was on average 30,46 cm and 28,24 cm for the DJ. The running velocity was on average 14,19 km/h. Pearson's correlation test for the correlation between DJ and running velocity was 0,463 and for the correlation between CMJ and running velocity it was 0,461. In both cases the significance was 0,006. Conclusions: There is a significant, moderate to strong correlation between jump height in DJ and CMJ and performance on long distance running on a running test in young elite orienteers.
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Amélioration de l'évaporation des gouttes à l'aide de nanoparticules et d'alcools / Enhancement of drops evaporation using nanoparticles and alcoholsChen, Pin 14 February 2018 (has links)
Au cours des dernières années, les exigences croissantes en matière de dissipation thermique à haut rendement pour la microélectronique, les engins spatiaux, les réacteurs nucléaires, etc., encouragent le développement d'échangeurs de chaleur de nouvelle génération. Le caloduc est l’un des équipements de refroidissement efficaces et potentiels. La plupart du transfert de masse et de chaleur se fait au niveau de la micro-région près de la ligne triple de contact (solide, liquide, vapeur), qui est essentielle à l'amélioration de la performance thermique du caloduc. Cette étude se concentre sur le processus d'évaporation de gouttes sessiles de deux nouveaux fluides de travail (solution binaire et nanofluide), qui possèdent une micro-région similaire à celle du caloduc. Le flux de Marangoni induit par le gradient de concentration et la conductivité thermique exceptionnelle devraient améliorer significativement le débit evaporé du mélange alcool-eau et du nanofluide de graphène, respectivement. Une combinaison de techniques acoustiques et infrarouges est développée pour suivre la variation de la concentration d'alcool pendant l'évaporation des gouttes des mélanges 1-butanol-eau et éthanol-eau. Selon l'observation du comportement d'évaporation à différentes températures du substrat, une série d'équations empiriques est suggérée pour prédire le taux d'évaporation de la solution binaire de 1-butanol-eau en considérant l'effet Marangoni thermal et solutal. De plus, l'effet de la PEGylation, de la concentration des nanoparticules et de la température du substrat sur l'évaporation de gouttes de graphène nanofluide est étudié par des méthodes microscopiques, optiques et infrarouges. Les résultats expérimentaux et l'analyse thermodynamique peuvent contribuer à la compréhension complète du mécanisme impliqué concernant les performances d'évaporation du nanofluide de graphène. / In recent years, increasing requirement in high efficient heat dissipation for micro-electronics, spacecraft, nuclear reactors etc., encourage the development of next generation heat exchanger. Heat pipe is one of potential effective cooling equipments and most of mass and heat transfer take place at micro-region near triple phase (solid, liquid, vapor) contact line of working fluid, which is essential to thermal performance improvement of heat pipe. This study focuses on the evaporation process of sessile droplets of two novel working fluids (binary solution and nanofluid), which possess similar micro-region to that in heat pipe. Concentration gradient induced Marangoni flow and exceptional thermal conductivity are expected to significantly enhance evaporation rate of alcohol-water mixture and graphene nanofluid, respectively. A combination of acoustic and infrared techniques is developed to track alcohol concentration variation during evaporation of 1-butanol and ethanol aqueous droplets. According to observation of evaporation behavior at different substrate temperature, a series of empirical equations is suggested to predict evaporation rate of 1-butanol-water binary solution droplet considering thermal and solutal Marangoni effect. In addition, the effect of PEGylation, nanoparticle concentration and substrate temperature on drop evaporation of graphene nanofluid are investigated by microscopic, optical and infrared methods. Experimental results and thermodynamic analysis can contribute to the full understanding of involved mechanism concerning evaporation performance of graphene nanofluid.
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Evaluation of Lower Limb Muscle Synergies in Paediatric Females with and without ACL InjuriesKemp, Laryssa 22 January 2020 (has links)
Purpose: Young adolescent females are at the highest risk of sustaining an ACL injury, which may alter their movement and muscle activation patterns yet there is a lack sex- and age- specific guidelines for ACL injury management. The purpose of this study was to (1) evaluate the effects of limb dominance in a healthy uninjured population to serve as a baseline for the ACL-deficient cohort and (2) provide evidence of the neuromuscular patterns and biomechanical loading of uninjured and ACL-deficient knee joints in a female paediatric population.
Methods: Eighteen active female adolescents with ACL rupture (ACLd) and 21 uninjured female adolescent controls matched for limb dominance (CON) participated in this study. Participants completed bilateral squats and drop vertical jumps (DVJ) while lower limb electromyography, kinetics and kinematics data were collected. Muscle synergies were extracted using a concatenated non-negative matrix factorization (CNMF) framework and compared between limbs, (CON dominant vs CON non-dominant and CON vs ACLd) across tasks and between limbs within tasks using intraclass correlation coefficients and statistical paramedic mapping.
Results: ACLd participants took significantly longer to perform the squat relative to their uninjured peers. No significant differences were found for hip, knee and ankle peak joint flexion angles and moments between populations for the squat. Squat and DVJ muscle synergies were equivalent for dominant and non-dominant uninjured control limbs. ACL injured (ACL deficient and contralateral limbs) exhibited greater variability in DVJ synergy vectors than for the squat task. When comparing across tasks, scaling coefficients were consistently higher for the DVJ for all populations. Conclusion: Differences in lower limb kinematics, muscle activity and muscle activation patterns between dominant and non-dominant limbs indicate that limb symmetry, a clinical tool commonly used to assess rehabilitation and return to play may not provide relevant results. DVJ scaling factors were larger than those of the squat for all groups, likely due to the increased demand of that task. ACLd and CON participants completed squats and DVJ with similar lower limb joint angle patterns and muscle activity. ACL injured groups had fewer consistent vectors across tasks demonstrating greater variability in muscle activation patterns. This increased variability may be due to the ACL injury however, as injured participants were not studied pre- injury it cannot be confirmed.
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