Autor: Karaś, D. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Experimental investigation of heat transfer performance coefficient in tube bundle of shell and tube heat exchanger in two-phase flow
Autorzy:: Karaś, M
Zając, D.
Ulbrich, R.
Powiązania:: https://bibliotekanauki.pl/articles/239957.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: two-phase flow
heat transfer coefficient
tube bundle
heat exchanger
DPIV
przepływ dwufazowy
współczynnik wnikania ciepła
pęk rur
wymiennik ciepła
Opis:: This paper presents the results of studies in two phase gasliquid flow around tube bundle in the model of shell tube heat exchanger. Experimental investigations of heat transfer coefficient on the tubes surface were performed with the aid of electrochemical technique. Chilton-Colburn analogy between heat and mass transfer was used. Twelve nickel cathodes were mounted on the outside surface of one of the tubes. Measurement of limiting currents in the cathodic reduction of ferricyanide ions on nickel electrodes in aqueous solution of equimolar quantities of K₃Fe(CN)₆ and K₄Fe(CN)₆ in the presence of NaOH basic solution were applied to determine the mass transfer coefficient. Controlled diffusion from ions at the electrode was observed and limiting current plateau was measured. Measurements were performed with data acquisition equipment controlled by software created for this experiment. Mass transfer coefficient was calculated on the basis of the limiting current measurements. Results of mass transfer experiments (mass transfer coefficient) were recalculated to heat transfer coefficient. During the experiments, simultaneously conducted was the the investigation of two-phase flow structures around tubes with the use of digital particle image velocimetry. Average velocity fields around tubes were created with the use of a number of flow images and compared with the results of heat transfer coefficient calculations.
Źródło:: Archives of Thermodynamics; 2014, 35, 1; 87-98
1231-0956
2083-6023
Pojawia się w:: Archives of Thermodynamics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Distribution of heat exchange coefficient and vertical two-phase cross-flow structures examination over tube bundles, using DPIV and electrochemical methods
Badanie nierównomierności rozkładu współczynnika wnikania ciepła na powierzchni rur oraz niejednorodności struktur wokół rur, przy przepływie mieszaniny dwufazowej z wykorzystaniem metody elektrochemicznej i DPIV
Autorzy:: Karaś, M
Zając, D.
Ulbrich, R.
Powiązania:: https://bibliotekanauki.pl/articles/2073407.pdf
Data publikacji:: 2013
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:: wymiana ciepła
DPIV
elektrochemiczna
przepływ dwufazowy
heat exchange
electrochemical method
two-phase flow
Opis:: Przeprowadzono badania nad przepływem dwufazowym wznoszącym przez przestawny i równoległy pęk rur. Za pomocą cyfrowej anemometrii obrazowej DPIV dokonano wizualizacji przepływu. Do określenia nierównomierności wymiany ciepła na powierzchni rurek wykorzystano elektrochemiczną metodę opartą na analogii wymiany ciepła i masy. Wyniki otrzymane dwiema metodami zestawiono badając wpływ rozkładu pola prędkości wokół rur na intensywność wymiany ciepła na jej powierzchni.
Two-phase vertical flow over a tube bundle was examined. To calculate the heat transfer coefficient on tubes' surface, the electrochemical technique based on heat and mass transfer analogy was used. The Digital Particle Image Velocimetry (DPIV) technique was applied to create velocity fields around tubes. The results obtained using both methods were compared in order to get an overview of velocity distribution around the tube and its influence on heat transfer intensity on its surface.
Źródło:: Inżynieria i Aparatura Chemiczna; 2013, 5; 431--432
0368-0827
Pojawia się w:: Inżynieria i Aparatura Chemiczna
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: The Influence of Plastic Forming Processes on the Dissolution Rate of Biocompatible Mg Alloys
Autorzy:: Boczkal, S.
Karaś, M.
Korczak, P.
Kapinos, D.
Koprowski, P.
Szymański, W.
Wroński, S.
Powiązania:: https://bibliotekanauki.pl/articles/355548.pdf
Data publikacji:: 2019
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: MgLiCaZn alloys
biomaterials
structure
properties
immersion test
Opis:: The effect of plastic deformation process on the dissolution rate of biocompatible Mg alloys was investigated. Two biocompatible MgLi1Ca0,2Zn1 and MgLi1Ca1Zn1 alloys were selected for the study. The alloys were deformed on a 100T press at a temperature of 350°C by conventional extrusion and by the equal channel angular extrusion process (ECAE). The grain size analysis showed a high degree of the grain refinement from approximately 110 mm in the initial state to 2.8 mm after the 3^rd pass of the ECAE process. Compared to as-cast state, the degree of strengthening has increased after plastic forming. The results of biodegradation tests have shown a significant increase in corrosion rate after both conventional extrusion and ECAE, although after subsequent ECAE passes, this rate was observed to slightly decrease in the MgLi1Ca1Zn1 alloy. Based on the results of macro- and microstructure examinations, the corrosion progress in samples after the extrusion process was described.
Źródło:: Archives of Metallurgy and Materials; 2019, 64, 3; 997-1004
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki