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DYMAMESI 2017
Kozieň, M.; Pešek, Luděk; Zolotarev, Igor
2017 - English
The Colloquium Dymamesi is continuing near the 20 years history of two conferences Dynamics of Machines and Interaction and Feedbacks. From 2017 the Colloquium is organized within the Czech-Polish (IT ASCR Prague & CUT Crakow) collaboration and the first one was held in CUT in Cracow. The prezentations were divided into the three sections: dynamics of machines, interactions and energetics. The Colloquium DYMAMESI 2017 was for the first time supported also by Programme Strategy 21 (AV21). Keywords: vibration; flutter; blade; sensor Available at various institutes of the ASCR
DYMAMESI 2017

The Colloquium Dymamesi is continuing near the 20 years history of two conferences Dynamics of Machines and Interaction and Feedbacks. From 2017 the Colloquium is organized within the Czech-Polish (IT ...

Kozieň, M.; Pešek, Luděk; Zolotarev, Igor
Ústav termomechaniky, 2017

Surface tension of aqueous binary mixtures under the supercooled conditions – Development of the measuring technique and preliminary data for water + lower alcohols
Vinš, Václav; Hykl, Jiří; Nikl, Zbyněk; Čenský, Miroslav; Hrubý, Jan
2017 - English
An experimental apparatus originally developed for the measurement of surface tension of supercooled water was modified such that it allows for measurement of binary aqueous mixtures. The measuring principle based on the capillary rise technique is similar to that employed in the previous measurements with pure water [J. Hrubý et al., J. Phys. Chem. Lett. 5 (2014) 425 and V. Vinš et al., J. Phys. Chem. B 119 (2015) 5567]. The temperature dependence of the surface tension is determined from the\nmeasured height of the liquid column elevated in a vertical capillary tube with an inner diameter of 0.32 mm. The aqueous liquid rises to a height of 60 mm to 95 mm depending on the solute concentration and the temperature. Preliminary tests performed with the binary mixtures of water with methanol, ethanol, and n-propanol at various concentrations and temperatures down to –28 °C approved functionality of the measuring technique. Some difficulties, such as influence of impurities on the liquid column elevation or formation of bubbles in the liquid column, were observed. The experimental apparatus is further being modified in order to obtain more accurate data for various aqueous mixtures. Keywords: aqueous mixture; surface tension; supercooled liquid Available at various institutes of the ASCR
Surface tension of aqueous binary mixtures under the supercooled conditions – Development of the measuring technique and preliminary data for water + lower alcohols

An experimental apparatus originally developed for the measurement of surface tension of supercooled water was modified such that it allows for measurement of binary aqueous mixtures. The measuring ...

Vinš, Václav; Hykl, Jiří; Nikl, Zbyněk; Čenský, Miroslav; Hrubý, Jan
Ústav termomechaniky, 2017

Kalibrace termočlánků typu K pomocí nové kalibrační aparatury
Blahut, Aleš; Hrubý, Jan
2017 - Czech
Byla provedena kalibrace dvou desítek průmyslových termočlánků typu K v teplotním rozsahu 30 °C až 150 °C. Pro kalibrace byla využita kalibrační aparatura, která byla nedávno vyvinuta v oddělení D2-Termodynamika. Aparatura umožňuje kalibrace teploměrů s přesností v řádu tisícin kelvinu v širokém rozsahu teplot. Provedená měření dále ukázala některé parazitní jevy daných termočlánků a byla navržena opatření pro jejich eliminaci. The calibration measurements were carried out for twenty industrial type K thermocouples in the temperature range from -30 °C to 150 °C. A new calibration apparatus, which was developed at department D2-Thermodynamics, was used for the calibrations. The new apparatus allows calibrations of various thermometers with the accuracy of a few thousandths of kelvin. The measurements revealed some parasitic effects of investigated thermocouples and particular steps were proposed to avoid these effects. Keywords: type K thermocouple; thermocouple calibration; temperature measurement Available at various institutes of the ASCR
Kalibrace termočlánků typu K pomocí nové kalibrační aparatury

Byla provedena kalibrace dvou desítek průmyslových termočlánků typu K v teplotním rozsahu 30 °C až 150 °C. Pro kalibrace byla využita kalibrační aparatura, která byla nedávno vyvinuta v oddělení ...

Blahut, Aleš; Hrubý, Jan
Ústav termomechaniky, 2017

Posouzení výpočtové dokumentace vybraných případů zabývajících se hodnocením nalezených indikací a výpočtem kritické velikosti vady ve svárových spojích na zařízeních českých JE
Pták, Svatopluk; Masák, Jan; Gabriel, Dušan
2017 - Czech
Ve zpráve je vypracováno posouzení výpoctové dokumentace vybraných prípadu zabývajících se hodnocením nalezených indikací a výpoctem kritické velikosti vady ve svarových spojích na zarízeních ceských JE. Pro každý prípad je detailne analyzován zvolený prístup k hodnocení daného prípadu nálezu. Konkrétne je provedeno posouzení z hlediska použitých materiálu, zatížení, možného rozvoje indikace, kategorizace napetí a hodnocení zbytkových napetí. Na záver každého posuzovaného prípadu je zhodnocena celková prukaznost predložené dokumentace. V rámci zprávy byla také poskytnuta konzultacní cinnost týkající se posuzování prípadu pomocí metodiky R6. Available at various institutes of the ASCR
Posouzení výpočtové dokumentace vybraných případů zabývajících se hodnocením nalezených indikací a výpočtem kritické velikosti vady ve svárových spojích na zařízeních českých JE

Ve zpráve je vypracováno posouzení výpoctové dokumentace vybraných prípadu zabývajících se hodnocením nalezených indikací a výpoctem kritické velikosti vady ve svarových spojích na zarízeních ceských ...

Pták, Svatopluk; Masák, Jan; Gabriel, Dušan
Ústav termomechaniky, 2017

Rotary laser vibration laboratory
Maturkanič, Dušan; Procházka, Pavel; Voronova, Evgeniya; Košina, Jan
2017 - English
The rotary laser vibration laboratory started the test operation at the Institute of Thermomachanics AS CR, v.v.i. at the end of 2015. The facility enables the research of high power turbomachines rotary bladed wheels. The paper describes the verification tests which were performed and focused on the equipment parameters at different conditions. Keywords: vibration; turbine; blade; laser; non-contact measurement; sensor; diagnostics Available at various institutes of the ASCR
Rotary laser vibration laboratory

The rotary laser vibration laboratory started the test operation at the Institute of Thermomachanics AS CR, v.v.i. at the end of 2015. The facility enables the research of high power turbomachines ...

Maturkanič, Dušan; Procházka, Pavel; Voronova, Evgeniya; Košina, Jan
Ústav termomechaniky, 2017

Incompressible and compressible viscous flow with low Mach numbers
Balázsová, M.; Feistauer, M.; Sváček, Petr; Horáček, Jaromír
2017 - English
In this paper we compare incompressible flow and low Mach number compressible viscous flow. Incompressible Navier-Stokes equations were treated with the aid of discontinuous Galerkin method in space and backward difference method in time. We present numerical results for a flow in a channel which represents a simplified model of the human vocal tract. Presented numerical results give a good correspondence between the incompressible flow and the compressible flow with low Mach numbers. Keywords: compressible Navier-Stokes equations; incompressible Navier-Stokes equations; discontinuous Galerkin method; finite element method; low Mach number flow Available at various institutes of the ASCR
Incompressible and compressible viscous flow with low Mach numbers

In this paper we compare incompressible flow and low Mach number compressible viscous flow. Incompressible Navier-Stokes equations were treated with the aid of discontinuous Galerkin method in space ...

Balázsová, M.; Feistauer, M.; Sváček, Petr; Horáček, Jaromír
Ústav termomechaniky, 2017

Topical Problems of Fluid Mechanics 2017
Šimurda, David; Bodnár, T.
2017 - English
The aim of the conference is to publish and to discuss the latest results of research in fluid mechanics. Keywords: experimental fluid mechanics; mathematical modelling; atmospheric boundary layer; turbulence; multiphase flow; magnetohydrodynamics Available at various institutes of the ASCR
Topical Problems of Fluid Mechanics 2017

The aim of the conference is to publish and to discuss the latest results of research in fluid mechanics.

Šimurda, David; Bodnár, T.
Ústav termomechaniky, 2017

Analýza kmitání modelu kola turbíny
Voronova, Evgeniya; Maturkanič, Dušan; Procházka, Pavel; Hodboď, Robert; Košina, Jan
2017 - Czech
Ve zprávě jsou shrnuty a analyzovány výsledky ověřovacího měření kola při otáčkách 2000 min^-1 . Stanoveny účinky přítomnosti vakua nebo podtlaku na vibrace kola při otáčkách 100 min^-1a při otáčkách 500 min^-1 . Porovnání měření při odlišných otáčkách, s volným kmitáním nebo s vynuceným kmitáním.\n The paper describes the verification tests which were performed for 2000 rpm. Determined effects of vacuum on wheel vibration at 100 rpm and at \n500 rpm. Compare measurements at different speeds, with free oscillation or forced oscillation.\n Keywords: vibratin; turbine; blade; laser; non-contact measurment Available at various institutes of the ASCR
Analýza kmitání modelu kola turbíny

Ve zprávě jsou shrnuty a analyzovány výsledky ověřovacího měření kola při otáčkách 2000 min^-1 . Stanoveny účinky přítomnosti vakua nebo podtlaku na vibrace kola při otáčkách 100 min^-1a při otáčkách ...

Voronova, Evgeniya; Maturkanič, Dušan; Procházka, Pavel; Hodboď, Robert; Košina, Jan
Ústav termomechaniky, 2017

CFD motivated applications of model order reduction
Isoz, Martin
2017 - English
The ongoing advances in numerical mathematics and available computing power combined with the industrial needs promote a development of more and more complex models. However, such models are, due to their complexity, expensive from the point of view of the data storage and the time necessary for their evaluation. The model order reduction (MOR) seeks to reduce the computational complexity of large scale models. We present an approach to MOR based on the proper orthogonal decomposition (POD) with Galerkin projection. The problems arising from the nonlinearities present in the original model are adressed within the framework of the discrete empirical interpolation method (DEIM). The main contribution of this work consists in providing a link between the POD-DEIM based MOR and OpenFOAM. OpenFOAM is an open-source CFD toolbox capable of solving even industrial scale processes. Hence, the availability of a link between OpenFOAM and POD-DEIM based MOR enables a direct order reduction for large scale systems originating in the industrial practice. Keywords: model order reduction; CFD; OpenFOAM Fulltext is available at external website.
CFD motivated applications of model order reduction

The ongoing advances in numerical mathematics and available computing power combined with the industrial needs promote a development of more and more complex models. However, such models are, due to ...

Isoz, Martin
Ústav termomechaniky, 2017

CFD study of gas flow through structured separation columns packings mellapak 250.x and mellapak 250.y
Isoz, Martin
2017 - English
In order to increase the size of the gas-liquid interface area and consequently the intensity of the mass transfer, the separation columns are usually lled with a geometrically complex packing. The packing highly increases intricacy of the ow in the column and also makes almost all types of hydrodynamic measurements impossible. Hence a reliable model of the ow in the complex geometry of the separation column packing is sought by the industry. We provide a CFD model for the gas ow through two types of commercial structured packings, Mellapak 250.X and Mellapak 250.Y. We validate the model on experimental data and use it to study the gas mixing capabilities of the packings. Keywords: CFD; OpenFOAM; structured packing; distillation, absorption Available at various institutes of the ASCR
CFD study of gas flow through structured separation columns packings mellapak 250.x and mellapak 250.y

In order to increase the size of the gas-liquid interface area and consequently the intensity of the mass transfer, the separation columns are usually lled with a geometrically complex packing. The ...

Isoz, Martin
Ústav termomechaniky, 2017

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