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  • 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.
11

Aerodynamická analýza měnitelné geometrie wingletu pro aplikaci na výkonném kluzáku / Aerodynamic analysis of morphing geometry application to sailplane winglet design

Malinowski, Matěj January 2017 (has links)
Diplomová práce se zabývá aerodynamickou analýzou a optimalizací wingletu kluzáku. Winglet je uvažován s možností změny tvaru v průběhu letu a optimalizační proces je zaměřen na odhalení optimálních tvarů v odlišných letových režimech. První část práce popisuje současné snahy v oblasti návrhu a vývoje wingletů s měnitelnou geometrií. Druhá část je zaměřena na popis funkce wingletu, následována třetí částí, která popisuje optimalizační metody, které mohou být použity během optimalizace. Další částí práce je popis letadla vybaveného wingletem, který byl vybrán pro optimalizaci. Tato část je následována požadavky stavebního předpisu kategorie letadla, které bylo vybráno. Následuje model typického letu tohoto letadla. Zbytek práce je organizován dle procesu hledání optimálních tvarů wingletu. Popis tvorby CAD modelu je následován popisem tvorby CFD modelu a popisem přípravy CDF simulací. V předposlední kapitole jsou odhaleny detaily optimalizačního procesu. Závěrečná část práce obsahuje vyhodnocení výsledků optimalizačního procesu.
12

Výpočet savky turbiny na zadané parametry / The computation of draft tobe of the turbine for giving parameters

Žák, František January 2017 (has links)
This diploma thesis describes design of a new shape of the draft tube for small hydro Katovice with maintaining built dimension. First part of this thesis is devoted to the formulation of the problem, description of basic function of the draft tube, its efficiency and other formulas. In the second part of this thesis the analysis is made for original design supported by CFD calculation. Furthermore a new design of the draft tube is made with comparison of original draft tube.
13

CFD analýza tvorby námrazy na letounu kategorie commuter / CFD analysis of icing effects on commuter aircraft configuration

Zima, Martin January 2019 (has links)
The Diploma Thesis concerns investigation of icing effects at L 410 NG aircraft. The aircraft is certified under FAR/CS/AP-23 Commuter category. An analysis was performed for existing Pneumatic De-icing Boots System at the wing area according to three flight configurations and icing conditions referring to document Part 25 Appendix C and O. The analysis was done by CFD solver FENSAP-ICE for various runs with respect to the icing envelope. Cases were assigned as two 2D cross-sections situated at the aircraft’s wing aileron part. Cross-sectional Reynold’s number oscillate between 4.5–8.5×106. Automatic operation of Pneumatic De-icing Boots System was proposed. Attention was paid to the ice accretion aft to the Pneumatic De-icing Boots System. The Appendix (Příloha) P6 contains an English written Article concerning main Diploma Thesis sections.
14

Optimalizace sacího potrubí zážehového motoru / Optimalization of Intake Manifold for SI Engine

Vondráček, Václav January 2011 (has links)
The main aim of this diploma thesis is to design two different types of air throttles in the intake manifold and compare their influence on a loss of dynamics of the flow of drawn air. The main purpose is to compare the mass flow for wholly opened air throttle. It deals with creating CDF model of intake manifold by using 3D scanner Atos and software Pro/Engineer WF5. During the work, the results of the CFD analysis were used for a real testing.
15

Návrh škrticí klapky zážehového motoru / Design of Throttle body for SI engine

Jantač, František January 2016 (has links)
This master’s thesis deals with the design of the throttle body of the intake manifold of a spark-ignition engine with regards to minimizing throttle loses at full engine load. The first part of this thesis focuses on the elements of intake tract structure on contemporary combustion engine including their design solutions and the theory of flow. The thesis also describes the creation of the 3-D CAD model of intake manifold with a throttle body and the description of the CFD flow simulation with the evaluation of resul.
16

Zvýšení stability chodu odstředivého kompresoru / Extension of Centrifugal Compressor Operational Stability

Růžička, Miroslav January 2016 (has links)
Centrifugal compressors with high pressure ratio are widely used in small aircraft turbine engines and turbocharges. At high rotational speeds they have narrow stable operating region and commonly used impellers with back swept blades are not able to ensure requested stability. In order to achieve wider stable operating region, some other anti-surge measures can be used, such as an Internal Recirculation Channel (IRC) located in compressor impeller inlet. This thesis deals with an investigation of IRC influence on centrifugal compressor operational parameters. As a first, the various recirculation channel geometry was studied by using of CFD analysis on simplified computational models. Those geometry, which indicated best results in terms of mass flow and looses in channel were used for testing on a model test device. Subsequently the same geometry was tested on real centrifugal compressor in experimental turbine engine to verify influence of IRC on compressor performance map – pressure ratio and efficiency. Simultaneously the CFD analyses of IRC with a 3D model of compressor impeller were performed and results compared with those, gained from measurement on model and compressor. In addition the measurement of flow field downstream the recirculation channel outlet slot with using of 3-hole pressure probe was performed and compared with flow velocity profiles evaluated from numerical simulations.
17

<strong>Optimization and Analysis of Squealer Tip  Geometries in Supercritical CO2</strong>

Stephen Thomas Bean (16324326) 14 June 2023 (has links)
<p>  </p> <p>In this thesis, two optimizations of squealer tip geometries are completed for first stage turbine blades for use in a supercritical carbon dioxide turbine. First, an optimization is performed on a baseline trapezoidal turbine blade and a set of solution geometries is chosen from along the Pareto front. Next, a second optimization is completed on an advanced blade design and the geometries are grouped by performance characteristics and geometric features. The success of similar geometries across these two optimizations is also analyzed and demonstrates consistency of performance increases from tip geometries over the baseline geometry. An analysis of a flat tip geometry in a stationary condition is also performed to begin validation of annular cascades as a method for testing squealer tip geometries. </p>
18

Design Improvements On Mixed Flow Pumps By Means Of Computational Fluid Dynamics

Ozgen, Onur 01 December 2006 (has links) (PDF)
The demand on high efficiency pumps leads the manufacturers to develop new design and manufacturing techniques for rotodynamic pumps. Computational Fluid Dynamics (CFD) software are started to be used during the design periods for this reason in order to validate the designs before the pumps are produced. However the integration process of CFD software into the design procedure should be made carefully in order to improve the designs. In this thesis, the CFD software is aimed to be integrated into the pump design procedure. In this frame, a vertical turbine type mixed flow pump is aimed to be designed and design improvements are intended to be made by applying numerical experimentations on the pump. The pump that is designed in this study can deliver 115 l/s flow rate against the head of 16 mWC in 2900 rpm. The effects of various parameters in the design are investigated by the help of CFD software during the design and best performance characteristics of the pump are aimed to be reached. The pump that is designed in this study is manufactured and tested in Layne Bowler Pumps Company Inc. The design point of the pump is reached within the tolerance limits given in the related standard. In addition, the results of actual test and numerical experimentation are compared and found to be in agreement with each other. The integration of CFD code to the design procedure is found quite useful by means of shortening design periods, lowering manufacturing and testing costs. In deed the effects of the design parameters are understood better by applying numerical experimentations to the designed pump.
19

Design And Performance Evaluation Of Mixed Flow Pumps By Numerical Experimentation And Axial Thrust Investigation

Cirit, Ali 01 October 2007 (has links) (PDF)
In this thesis a vertical turbine mixed flow pump that has a flow rate of 40 l/s and 16 mwc head at 2900 rpm is designed. Effect of design parameters are investigated and flow inside the pump is analyzed with the help of numerical experimentations. The designed pump is manufactured and tested in Layne Bowler Pumps Company and completed in T&Uuml / BiTAK - TEYDEB project. Pump is designed in the tolerance limits that are defined in the standard TS EN ISO 9906. Numerical experimentation results for performance charecteristics show the same trend with the test results. In addition, axial thrust measurements are done on the designed pump with using load cells. Effect of balancing holes and balancing ring are investigated. Balancing holes are drilled at various diameters at the back side of the impellers and its effect is analyzed on the pump performance characteristics. Test results are compared with different approaches.
20

Modifikace krevního čerpadla, jako srdeční náhrady / Modification of a blood pump as a heart replacement

Simandl, Mirek January 2019 (has links)
The master’s thesis deals optimization of regenerative pump and axial pump with ring motors that are designed as a heart replacement. Analysis of the koncepts is performed which were made in previous master’s thesis. There is created a new design of construction and hydraulition with using flat motors based on the analysis. The compact assembly of two impeller was formulated that replaced left and right heart and it served as a function of heart replacement. A functional model of the pump is created, there is measured characteristics of impeller and results are compared with CFD analysis. The design requirements some parts of the axial pump are added and it’s deviced feasibility analysis.

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