Úloha proudění v tepelné analýze motoru

The paper presents the relations used for CFD simulation of the flow around the body. The procedures for creation of practically usable computer model of bigger mechanical parts and application of its boundary conditions are described, obtained results are presented. The aim of the work was the analysis of temperature field and cooling parameters of current motor geometry with expectation of further optimization to achieve better cooling power and to reduce the mass of the motor.Předložený článek prezentuje vztahy uživané při numerické CFD analýze obtekaného tělesa. Jsou popsány postupy pro tvorbu prakticky použitelného počítačového modelu strojního celku větších rozměrů, aplikace okrajových podmínek a jsou prezentovány získané výsledky. Cílem práce byla analýza teplotního pole a parametry chlazení současné geometrie motoru s výhledem na případnou optimalizaci tvaru za účelem lepší chladivosti a snížení hmotnosti motoru

Tangent modulus in numerical integration of constitutive relations and its influence on convergence of N-R method

For the numerical solution of elasto-plastic problems with use of Newton-Raphson method in global equilibrium equation it is necessary to determine the tangent modulus in each integration point. To reach the parabolic convergence of Newton-Raphson method it is convenient to use so called algorithmic tangent modulus which is consistent with used integration scheme. For more simple models for example Chaboche combined hardening model it is possible to determine it in analytical way. In case of more robust macroscopic models it is in many cases necessary to use the approximation approach. This possibility is presented in this contribution for radial return method on Chaboche model. An example solved in software Ansys corresponds to line contact problem with assumption of Coulomb’s friction. The study shows at the end that the number of iteration of N-R method is higher in case of continuum tangent modulus and many times higher with use of modified N-R method, initial stiffness method

Fast New Method for Temporary Chemical Passivation

The main material parameter of silicon, that influences the effectiveness of photovoltaic cells, is the minority carrier bulk lifetime.It may change in the technological process especially during high temperature operations. Monitoring of the carrier bulk-lifetimeis necessary for modifying the whole technological process of production. For the measurement of the minority carrier bulk-lifetimethe characterization method MW PCD (Microwave Photoconductance Decay) is used, where the result of measurement is the effectivecarrier lifetime, which is very dependent on the surface recombination velocity and therefore on the quality of a silicon surfacepassivation.This work deals with an examination of a different solution types for the chemical passivation of a silicon surface. Varioussolutions are tested on silicon wafers for their consequent comparison. The main purpose of this work is to find optimal solution, whichsuits the requirements of a time stability and start-up velocity of passivation, reproducibility of the measurements and a possibilityof a perfect cleaning of a passivating solution remains from a silicon surface. Another purpose of this work is to identify the parametersof other quinhydrone solutions with different concentrations as compared with the quinhydrone solution in methanol witha concentration of 0.07 mol/dm³ marked QM007 (referential solution).The method of an effective chemical passivation with a quinhydrone in methanol solution was suggested. The solution witha concentration of 0.07 mol /dm3 fulfills all required criteria. The work also confirms the influence of increased concentrationquinhydrone on the temporal stability of the passivation layer and the effect for textured silicon wafers. In conclusion, the influenceof an illumination and the temperature on the properties of the passivating solution QM007 is discussed

Exhaustion of Flammable Dusts in Practice and Their Explosion Prevention

Import 29/09/2010Tato diplomová práce je tvořena dvěma částmi a to teoretickou a praktickou části. Teoretická část seznamuje čtenáře s technologií na odsávání (čištění vzduchu od tuhých prachových příměsí), dále charakterizuje podmínky, kdy hrozí nebezpečí výbuchu, poslední díl této části nabízí přehled jednotlivých druhů a způsobů proti výbuchové ochrany. Praktická část mé práce, se zabývá konkrétním řešením jednotlivých způsobů protivýbuchové ochrany na definované filtrační jednotce, porovnání těchto způsobů řešení a návrh podmínek pro bezpečný provoz daného zařízení.This diploma thesis consists of two parts: theoretical and practical. The theoretical part informs the reader about exhaust technology (cleansing of air of solid dust impurities). It also specifies conditions under which a danger of explosion might occur and lastly, it offers overview of individual types and ways of explosion protection. The practical part of my paper deals with definite solution of individual types of explosion protection on defined filter unit, their comparison and a draft of conditions for safe operation of the given device.Prezenční030 - Katedra požární ochrany a ochrany obyvatelstvavýborn

Founding in region of Palkovice

Úkolem bakalářské práce Zakládání v Palkovicích je porovnání podmínek pro zakládání v různých lokalitách v okolí Palkovic. Jako kritérium pro porovnání byl použit výpočet únosnosti základové půdy a výpočet sedání základové konstrukce. V daných lokalitách se uvažovaly situace bez vlivu podzemní vody i s vlivem podzemní vody.Objective of this bachelor´s thesis Foundation in region of Palkovice is to compare the conditions of foundations in different locations in the region of Palkovice. Calculations of bearing capacity of foundation soil and settlement analysis of the foundation structure were the criteria of comparison. Variants with and without groundwater were included in the calculations.

RESIDUAL VOLUMES AND FINAL WEIGHTS IN DIFFERENT TYPES OF PLASTIC INFUSION CONTAINERS

Objective: To compare the residual volumes, the drained volumes, and the final weights of different infusion containers with different volumes and degrees of flexibility. The risk of drug error can be aggravated by a high residual volume remaining in a drained intravenous container. A high residual volume can also increase the final weight of the container after drainage.Methods: A total of 80 infusion containers containing normal saline of four different brands (Viaflo® and Freeflex® flexible bags and KabiPac® and Ecoflac® Plus semi-rigid containers) in two different volumes (250 and 500 ml) were tested. Every container type was tested ten times under close-vent conditions. Residual and total drained volumes and weights of drained containers before and after drying were assessed. Results: The residual volume that remained in the intravenous containers tested was lower than 2% of the declared volume, with only one exception (KabiPac® 250 ml), in which the residual volume was higher than 10% of the declared volume. Using gravity drainage, among the 250 ml containers, only one (Viaflo®) reached the full declared total drained volume of 250 ml. By contrast, among the 500 ml containers, only one failed to reach the declared drained volume. There were significant differences in favor of flexible bags in the final weights of containers after drainage, and in one case (250 ml KabiPac® semi-rigid container) the residual volume accounted for more than a half of the final container weight.Conclusion: All four types of containers can be used with the same resulting quality of parenteral treatment. Selection of a specific type of container will be affected primarily by the price (both acquisition and waste disposal costs) and requirements of personnel for handling the container.Keywords: Infusion therapy, Flexible, and semi-rigid containers, Residual volum

Design of Landslide Remediation

Úkolem diplomové práce s názvem „Návrh sanace sesuvu“ je, na základě získaných znalostí o problematice svahových sesuvů a jejich možných řešení, stanovit z poskytnutých podkladů příčiny vzniku sesuvu na silnici II. třídy mezi obcemi Koryčany - Jestřabice a navrhnout optimální způsob sanace.Main goal of thesis entitled "Landslide remediation design" is - based on acquired knowledge and submitted documents about the problematic of landslides - to determine the causes of the landslides on II. class road between villages Koryčany and Jestřabice and to propose optimal redevelopment.

Comparison of co-rotational and other algorithms for geometrically nonlinear static analysis with small strains

The presented work was supported by: the Specific Reasearch „Application of Modern Computational and Experimental Approaches in Applied Mechanics“ (SP2023/027); the Ministry of Education, Youth and Sports of the Czech Republic through the e-INFRA CZ (ID:90254); the science and research support in the Moravian-Silesian region (RRC/12/2022)