• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 58
  • 19
  • 18
  • 5
  • 5
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 136
  • 136
  • 35
  • 28
  • 23
  • 23
  • 14
  • 13
  • 13
  • 13
  • 12
  • 12
  • 12
  • 11
  • 11
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Simulation of soil water movement model (SWaMM) using the Spider Distributed System

Wang, Li 01 January 2003 (has links)
This project implements a real application on the Spider II, which is a simulation of Soil Water Movement Model. The main objectives of this project were to develop a parallel and distributed algorithm for the Soil Water Model; implement the Soil Water Movement Simulation model on the Spider II distributed system and to evaluate the performance of simulating the Soil Water Movement Model on Spider II.
92

Analýza působení spínacího systému jističe nn na tepelnou spoušť / Analysis of effect of the switching system of low voltage breaker on the thermal tripping unit

Liščák, Jiří January 2018 (has links)
Main aims of this master’s thesis are executing measurements and simulations on low voltage circuit breaker and analyzing effect of the switching mechanism on the thermal tripping unit. There are two programs used for simulations in this thesis ANSYS and SolidWorks Flow Simulation. As another part of the thesis were done two types of tests. First was electrical durability test and second one was warming test. In this thesis were measured values of warming on whole current path not only on thermal tripping unit.
93

Návrh sacího systému přeplňovaného motoru Formule Student / Formula Student Intake System Design

Kříž, Radim January 2020 (has links)
This diploma thesis deals with the analysis of the intake system of a turbocharged Formu-la Student combustion engine. The thesis contains a brief description of the intake system of a passenger vehicle and the intake system of a Formula Student vehicle. Part of the work is the design of an electronic throttle. The type of throttle valve was selected based on a research of individual types used nowadays. Furthermore, simulations of the flow of the air through the intake system are performed and the results are used in the design cal-culations.
94

Návrh 3D tiskárny typu delta pi s temperovanou podložkou s využitím systémů CAE / Design of delta pi 3D printer with tempered bed using CAE systems

Koudela, Ondřej January 2015 (has links)
This master's thesis deals with 3D printing using non-commercial 3D RepRap type printers. This work briefly describes development trends of non-commercial RepRap printers, theory of FDM print with analysis and comparison of materials, which are used in printing and the issue of the finite volume method and theory of heat diffusion. The practical part based on simulations from SolidWorks Flow Simulation discussed two basic methods of heating hot bed, then the temperature profile of hot end and the heat flow in full assembly of the printer. Outcome of this work is design an optimized model and the physical assembly of 3D printer delta pi type.
95

Optimalizace chlazení koncentrátorového fotovoltaického článku pomocí systémů CAE / Optimization of cooling the photovoltaic cell using CAE systems

Sodomka, Pavel January 2014 (has links)
This thesis deals with the optimization of the concentrate photovoltaic cell cooling system through the CAE system. In the theoretical part, the thesis treats there the problematic of the photovoltaics and focuses on the concentrator cell and its problems coupled with the cooling system and the sink of heat. In the next theoretic part, it also analyses there the problematic of the conduit and transfer of heat. Moreover, the mathematical description of the fluid flow, the finite-volume method that is used in the SolidWorks Flow Simulation for the calculations, are also described there. In the practical part, the models and steps which depict precisely all the process of the heat cooling optimization are mentioned. All the proposed variants are mutually compared and put up for the discussion about their advantages and disadvantages. Lastly, the resultant model was also put through the simulation with the suggested radiational component that gave precision to the results. In the end of the thesis, there was made out the documentation of the final model drawings.
96

Působení sekundárních elektrických přístrojů na oteplení skříně rozváděče. / Influece of secondary apparatuses on assembly box heating

Dobiáš, Pavel January 2016 (has links)
This master's thesis deals with the temperature-rise of selected parts of the low-voltage switchgear. The theoretical part describes the physical principles and the basic mechanisms of heat transfer. The next part describes the possible effect of elevated temperature on the device inside the switchgear. The master's thesis is awarded by ABB Ltd., so another part is dedicated to MNS switchgear. The following part describes the permitted limit of temperature-rise of switchgear in accordance with IEC 61439-1. In the practical part is a calculation temperature-rise of selected part of switchgear based on IEC 60890. Model in SOLIDWORKS Flow Simulation was created for the same part of the switchgear and thermal analysis was performed. The values of allowable temperature rise of individual parts are compared with the results obtained by calculations and simulations. In the last part is verified the possibility of calculating the temperature-rise in the EPLAN software.
97

Výpočet teplotního pole přípojnicového mostu / Calculation of temperature field of the busbar bridge

Měrka, Ivan January 2016 (has links)
This term project’s aim is to theoreticaly analyze thermal phenomena and losses in electrical power devices, describe the design and application of UniGear ZS1 type switchgear, put together a computer simulation model for thermal calculations of current and optimized solution and finally to discuss obtained results and compare them with experimentally acquired values. The main objective of this project is to determine, whether simulation is a viable and reliable enough method, that it could replace the costly real life physical testing. Modelling of the progress of thermal processes in different parts of the examined busbar will be done in computer aided design program Solidworks and its simulation plugin Flow Simulation.
98

Návrh a zkoušení rozváděčů nn / Designing and testing of low voltage switchgears

Kovář, Zdeněk January 2017 (has links)
The thesis is focused on a temperature-rise of a low-voltage switchgear. The first part of the work deals with a technical standard related to the chosen topic, compares software used for designing switchgear in practice and familiarizes with the working environment of the software selected for this work. The main part of the work is dedicated to a measurement and a simulation of the temperature-rise of the low-voltage switchgear. The measurement involved testing of the switchgear with regard to the individual functional units and to the whole switchgear. Subsequently, the simulation of the temperature-rise of the switchgear followed. Software used in this work is SolidWorks Flow Simulation chosen due to a wide range of functions. According to the findings there were proposed adjustments of the switchgear with respect to the technical parameters and the economic aspect in the last part of the thesis.
99

Ein Beitrag zur makroskopischen Simulation von Passagierströmen zwischen kooperierenden Flughäfen unter Nutzung des SYSTEM DYNAMICS Zuganges nach Forrester

Mühlhausen, Thorsten 22 December 1999 (has links)
Der stetig steigende Flugverkehr führt zu Kapazitätsengpässen an vielen Großflughäfen. Die Möglichkeit des Ausbaus ist häufig aufgrund von Arealmangel und Widerstand aus der Bevölkerung (zumeist durch Umweltgesichtspunkte motiviert) nicht realisierbar. Ein Ausweg bietet hier die Kooperation mehrerer Flughäfen. So kann ein in der Nähe eines Großflughafens angesiedelter Regionalflughafen als zusätzliche Runwaygenutzt werden. Ausschlaggebend hierbei sind die landseitigen Anbindungen beider Flughäfen. Beide müssen zusammen annähernd wie ein Flughafen operieren. Der Optimierung dieses Systems kooperierender Flughäfen widmet sich die vorliegende Arbeit. Es werden zwei Szenarien näher untersucht und bewertet: Konventionelle S-Bahn-Verbindung unter Ausnutzung der vorhandenen Infrastruktur und mit einem fixen Fahrplan (traditioneller Betrieb) Verbindung unter Nutzung einer vollautomatischen Bahn mit bedarfsabhängiger Anpassung der Taktrate Die Modellierung erfolgt hierbei durch eine makroskopische Simulation auf der Basis des SYSTEM DYNAMICS Zugangs nach Forrester. Dieser zeichnet sich besonders durch seine prozessnahe Darstellung aus. In dieser Arbeit wird die Anwendbarkeit von SYSTEM DYNAMICS auf die Modellierung von Passagierströmen an Verkehrsknoten nachgewiesen, die Passagierverzögerung bei der Verknüpfung von Flughäfen ermittelt und der Ressourcenverbrauch, d.h. der Bedarf an Betriebsmitteln für die Verbindung bestimmt. / Steadily increasing air traffic leads to capacity problems at many major airports. In most cases it is not possible to enlarge the airport due to lack of area or resistance of the population (mainly motivated by environmental aspects). One way out is the cooperation of airports. It can be possible to use a smaller airport in the vicinity of a major airport as an additional runway. In this case the land-side connections between both airports are very important. The two airports have to operate like one big airport. This work deals with the optimization of the system of cooperating airports. Two scenarios are analyzed and rated in more detail: Conventional railway connection with utilization of existing infrastructure and with a fixed time table (traditional operational regime) Connection with an automated people mover with demand control schedule For macroscopic modeling the SYSTEM DYNAMICS approach by Forrester is used. The main feature is a very good real world representation. This work shows the applicability of SYSTEM DYNAMICS for modeling passenger flows at traffic junctions, calculates the passenger delay, which occurs between connected airports and specifies the consumption of resources, i.e. equipment necessary for the connection.
100

Výpočtové modelování samobuzeného kmitání lidských hlasivek / Computational Modelling of Self- oscillations of the Human Vocal Folds

Hájek, Petr January 2022 (has links)
The presented dissertation thesis deals with a simulation of the human phonation in terms of latest theories. Phonation is considered here as a bi-directional fluid-structure-acoustic interaction, where the interaction between all three physical domains occurs due to the unsteady viscous compressible Navier-Stokes equations. There is a solid knowledge background in the first part of the thesis. It concerns the latest concepts in computational modeling of the human phonation, the most important and recent theories about the human voice production and some key aspects of the human anatomy, physiology and pathology. Also voice assessment is discussed. The second part of the thesis describes an in-depth analysis of a phonation simulation in a planar computational model. The basic concepts proceed from algorithms developed in the Institute of Solid Mechanics, Mechatronics and Biomechanics. Created models are able to reproduce sounds of all Czech vowels and the most common evaluated parameters very close to physiological ranges. The simulated pathology, Reinke's edema, is demonstrated in order to explore its influence on the vowel sound. The third part focuses on modeling of phonation in a spatial computational model. All Czech vowels are simulated also here and compared to the planar model and to actual measurement. The spatial model serves as the starting point to modeling of a longitudinal pretension incorporated in the vocal folds. In the last part of the thesis, a modeling of the phonation with vocal folds pretension is investigated. Although the models are tuned to a rather soft phonation, the results are in agreement with the relevant physiologic phenomena. While the spatial model is highly computationally expensive, a hybrid planar model with pretension is proposed. A special attention is paid to the analysis of self-sustained oscillation of the vocal folds. It is shown, the planar model cannot reproduce such kind of oscillation in the actual version, albeit time of oscillation was considerably extended. On the other hand, oscillation of the spatial vocal folds are stabilized without effects accompanying subduing of oscillation. It can be supposed that the spatial model is able to reproduce self-sustained oscillation as a basic principle present during the human phonation.

Page generated in 0.0763 seconds