Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "heat transfer enhancement" wg kryterium: Temat


Wyświetlanie 1-13 z 13
Tytuł:
Experimental investigation and characteristics of multiwalled carbon nanotube aqua nanofluids from a flat plate heater surface in a pool
Autorzy:
Vasudevan, D.
Senthil Kumar, D.
Murugesan, A.
Vijayakumar, C.
Powiązania:
https://bibliotekanauki.pl/articles/201185.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nanofluids
critical heat flux
heat transfer coefficient
boiling
heat transfer enhancement
Opis:
In this experimental investigation, the critical heat flux (CHF) of aqua-based multiwalled carbon nanotube (MWCNT) nanofluids at three different volumetric concentrations 0.2%, 0.6%, and 0.8% were prepared, and the test results were compared with deionized water. Different characterization techniques, including X-ray diffraction, scanning electron microscopy and Fourier transform infrared, were used to estimate the size, surface morphology, agglomeration size and chemical nature of MWCNT. The thermal conductivity and viscosity of the MWCNT at three different volumetric concentrations was measured at a different temperature, and results were compared with deionized water. Although, MWCNT-deionized water nanofluid showed superior performance in heat transfer coefficient as compared to the base fluid. However, the results proved that the critical heat flux is increased with an increase in concentrations of nanofluids.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 547-554
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibration-Assisted Laser Surface Texturing and Electromachining for the Intensification of Boiling Heat Transfer in a Minichannel
Autorzy:
Piasecka, M.
Strąk, K.
Grabas, B.
Powiązania:
https://bibliotekanauki.pl/articles/356459.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
developed surface
vibration laser texturing
electromachining
heat transfer enhancement
minichannel
Opis:
The paper describes applications of the vibration-assisted laser surface texturing and spark erosion process as methods of modifying properties and structures of metal surfaces. Practical aspects of the use of produced surfaces in the heat exchanger with a minichannel have been described. Compared with smooth surfaces, developed metal surfaces obtained by vibration-assisted laser surface texturing and electromachining show more effective heat transfer. The local heat transfer coefficient for the saturated boiling region obtained for developed surfaces had the values significantly higher than those obtained for the smooth plate at the same heat flux. The experimental results are presented as the heated plate temperature (obtained from infrared thermography) and relationships between the heat transfer coefficient and the distance along the length of the minichannel for the saturated boiling region.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 1983-1990
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the method of fundamental solutions to the analysis of fully developed laminar flow and heat transfer
Autorzy:
Mrozek, K.
Mierzwiczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/280988.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
laminar flow
finned tube
heat transfer enhancement
method of fundamental solutions
Opis:
In this study, fully developed laminar flow and heat transfer in an internally longitudinally finned tube are investigated through application of the meshless method. The flow is assumed to be both hydrodynamically and thermally developed, with a uniform outside-the-wall temperature. The governing equations have been solved numerically by means of the method of fundamental solutions in combination with the method of particular solutions to obtain the velocity and temperature distributions. The advantage of the proposed approach is that it does not require mesh generation on the considered domain or its boundary, but uses only a cloud of arbitrarily located nodes. The results, comprising the friction factor as well as the Nusselt number, are presented for varied length values and fin numbers, as well as the thermal conductivity ratio between the tube and the flowing fluid. The results show that the heat transfer improves significantly if more fins are used.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 505-518
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady natural convection in micropolar nanofluids
Autorzy:
Rup, K.
Nering, K.
Powiązania:
https://bibliotekanauki.pl/articles/240090.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micropolar fluid
nanofluid
heat transfer enhancement
płyn mikropolarny
nanopłyn
intensyfikacja wymiany ciepła
Opis:
This paper presents the analysis of momentum, angular momentum and heat transfer during unsteady natural convection in micropolar nanofluids. Selected nanofluids treated as single phase fluids contain small particles with diameter size 10-38.4 nm. In particular three water-based nanofluids were analyzed. Volume fraction of these solutions was 6%. The first of the analyzed nanofluids contained TiO2 nanoparticles, the second one contained Al2O3 nanoparticles, and the third one the Cu nanoparticles.
Źródło:
Archives of Thermodynamics; 2014, 35, 3; 155-170
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow and heat transfer characteristics of a novel airfoil-based tube with dimples
Autorzy:
Pei, Houju
Liu, Meinan
Yang, Kaijie
Zhimao, Li
Liu, Chao
Powiązania:
https://bibliotekanauki.pl/articles/2173696.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat transfer enhancement
airfoil-based tube
dimple
comprehensive performance
wzmocnienie wymiany ciepła
rura
wgłębienie
wykonanie kompleksowe
Opis:
The performance of a novel airfoil-based tube with dimples is numerically studied in the present work. The effect of Reynolds number Re, dimples number N, relative depth H/D, and cross-distribution angle α on flow and heat transfer characteristics are discussed for Re in the range between 7,753 and 21,736. The velocity contour, temperature contour, and local streamlines are also presented to get an insight into the heat transfer enhancement mechanisms. The results show that both the velocity magnitude and flow direction change, and fluid dynamic vortexes are generated around the dimples, which intensify the flow mixing and interrupt the boundary layer, resulting in a better heat transfer performance accompanied by a certain pressure loss compared with the plain tube. The Nusselt number Nu of the airfoil-based tube increases with the increase of dimples number, relative depth, and Reynolds numbers, but the effect of cross-distribution angle can be ignored. Under geometric parameters considered, the airfoil-based tube with N = 6, H/D = 0.1, α = 0° and Re = 7,753 can obtain the largest average PEC value 1.23. Further, the empirical formulas for Nusselt number Nu and friction factor f are fitted in terms of dimple number N, relative depth H/D, and Reynolds number Re, respectively, with the errors within ± 5%. It is found that the airfoil-based tube with dimples has a good comprehensive performance.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 4; art. no. e141984
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Condensation enhancement by means of electrohydrodynamic techniques
Autorzy:
Butrymowicz, D.
Karwacki, J.
Trela, M.
Powiązania:
https://bibliotekanauki.pl/articles/239917.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
condensation
electrohydrodynamic technique
heat transfer enhancement
enhanced tubes
kondensacja
elektrohydrodynamika
technika
intensyfikacja wymiany ciepła
rura
wzmocnienie
Opis:
Short state-of-the-art on the enhancement of condensation heat transfer techniques by means of condensate drainage is presented in this paper. The electrohydrodynamic (EHD) technique is suitable for dielectric media used in refrigeration, organic Rankine cycles and heat pump devices. The electric field is commonly generated in the case of horizontal tubes by means of a rod-type electrode or mesh electrodes. Authors proposed two geometries in the presented own experimental investigations. The first one was an electrode placed just beneath the tube bottom and the second one consisted of a horizontal finned tube with a double electrode placed beneath the tube. The experimental investigations of these two configurations for condensation of refrigerant R-123 have been accomplished. The obtained results confirmed that the application of the EHD technique for the investigated tube and electrode arrangement caused significant increase in heat transfer coefficient. The condensation enhancement depends both on the geometry of the electrode system and on the applied voltage.
Źródło:
Archives of Thermodynamics; 2014, 35, 4; 3-27
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of thermal performance factor for solar air heaters with artificially roughened channels
Autorzy:
Siddique, Waseem
Raheem, Aneeq
Aqeel, Muhammad
Qayyum, Sualeh
Salamen, Tareq
Waheed, Khalid
Qureshi, Kamran
Powiązania:
https://bibliotekanauki.pl/articles/1845043.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
turbulence promoter
solar air heater
heat transfer enhancement
thermal performance factor
słoneczny grzejnik powietrzny
intensyfikacja wymiany ciepła
współczynnik wydajności cieplnej
Opis:
Heat transfer augmentation has become the utmost industrial desire. Turbulence promoters seems to be a better option for better heat transfer but at the expense of enormous pressure drop. In the current study, experimental optimization of heat transfer and pressure drop in various configurations of ribbed and corrugated surfaces on the bottom wall of the Solar Air Heater channel, having aspect ratio of 26:5 was performed. The results were evaluated in terms of enhancement in heat transfer (Nu/Nu s), friction factor ratio (f/f s) and thermal performance factor ( η). Three different cases and nine configurations with a pitch to rib/corrugation height ratio of 4.0 were studied. Case A consists of a smooth, continuous square rib, inline and staggered broken ribs. Case B comprises 30°, 45°, 60° and 90° trapezoidal corrugated geometries while Case C is the comparison of smooth, wavy corrugated and the best configurations of cases A and B. The results show that rectangular duct with staggered broken ribs and trapezoidal corrugation at 45° are the best configurations for case A and B, respectively. The 45° corrugated configuration is the best one amongst all, with values of 1.53, 1.5 and 1.33% for Nu/Nu s, f/f s and η respectively.
Źródło:
Archive of Mechanical Engineering; 2021, LXVIII, 2; 195-225
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat transfer enhancement from a heated plate with hemispherical convex dimples by forced convection along with a cross flow jet impingement
Autorzy:
Patro, P.
Garnayak, S.
Powiązania:
https://bibliotekanauki.pl/articles/265024.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wymiana ciepła
uderzenie strumieniowe
przepływ krzyżowy
heat transfer enhancement
jet impingement
convex dimpled surface
SST k-w model
cross flow
Opis:
In the present study, heat transfer from a small three dimensional rectangular channel due to turbulent jet impinging from a nozzle normal to the main flow at the inlet has been investigated. Hemispherical convex dimples are attached to the bottom plate from where heat transfer calculations are to be performed. Numerical simulations were performed using the finite volume method with […] turbulence model. The duct and nozzle Reynolds number are varied in the range of […], respectively. Different nozzle positions (X/D = 10.57, 12.88, 15.19) along the axial direction of the rectangular duct have been considered. It has been found that higher heat transfer is observed at X/D = 10.57 as compared to the other positions. The heat transfer enhancements with and without cross-flow effects have also been compared. It has been shown that the heat transfer rate with cross-flow is found to be much higher than that without crossflow. Also, the effect of dimples on the heated surface on heat transfer was investigated. The heat transfer is found to be greater in the presence of a dimpled surface than a plane surface.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 1; 127-141
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A review on active techniques in microchannel heat sink for miniaturization problem in electronic industry
Autorzy:
Bhandari, Prabhakar
Singh, Jarnail
Kumar, Kaushal
Ranakoti, Lalit
Powiązania:
https://bibliotekanauki.pl/articles/2175199.pdf
Data publikacji:
2022
Wydawca:
Centrum Badań i Innowacji Pro-Akademia
Tematy:
microchannel heat sink
active technique
electrostatic force
flow pulsation
magnetic field
heat transfer enhancement
radiator mikrokanałowy
siła elektrostatyczna
pulsacja przepływu
pole magnetyczne
wymiana ciepła
Opis:
With continuous miniaturization of modern electronic components, the need of better cooling devices also keeps on increasing. The improper thermal management of these devices not only hampers the efficiency but can also cause permanent damage. Among various techniques, microchannel heat sink has shown most favourable performance. To further enhance the performance, two techniques i.e., active and passive are used. In passive technique, no external power source is required like heat sink design alteration and working fluid modification. External power source is necessary for heat transfer augmentation in the microchannel heat sink when using the active approach. Due to compact size of microchannel, active techniques are not used more often. However, the present work highlights the different active technique used in microchannel i.e., Electrostatic forces, flow pulsation, magnetic field, acoustic effects, and vibration active techniques. Above mentioned techniques have been analysed in detail.
Źródło:
Acta Innovations; 2022, 45; 45--54
2300-5599
Pojawia się w:
Acta Innovations
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption-desorption processes in adsorption chillers
Proces adsorpcji i desorpcji w agregacie adsorpcyjnym
Autorzy:
Gwadera, M.
Powiązania:
https://bibliotekanauki.pl/articles/93996.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
adsorption chillers
heat and mass transfer enhancement
mathematical modeling
agregat adsorpcyjny
ulepszenie przepływu ciepła i masy
modelowanie matematyczne
Opis:
The aim of this paper is to present the adsorption chillers technology. The operating principle of these systems, the adsorbent-adsorbate pairs that are frequently applied and the enhancement techniques that allow improvement of their efficiency are presented. Analysis of the mass transfer and principles of mathematical modeling of such systems are also discussed. In the further part of the text, the results of experimental studies and comparison of these results with calculations based on the mathematical model of adsorption were presented.
Niniejsza praca ma na celu zaprezentowanie technologii agregatów adsorpcyjnych. Przedstawiono zasadę działania takich systemów, a mianowicie par adsorbat-adsorbent, które są często stosowane oraz technik ulepszania, które pozwalają na poprawę ich wydajności. Przedyskutowano także analizę przepływu masy oraz zasad modelowania matematycznego takich systemów. W dalszej części przedstawiono wyniki badań eksperymentalnych oraz porównanie takich wyników z obliczeniami na podstawie modelu matematycznego adsorpcji.
Źródło:
Agricultural Engineering; 2016, 20, 2; 81-89
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ parametrów procesowych na wymianę masy i ciepła podczas adsorpcji wody na silikażelu
The effect of process paramaters on mass and heat transfer during adsorption of water on silica gel
Autorzy:
Gwadera, M.
Powiązania:
https://bibliotekanauki.pl/articles/134835.pdf
Data publikacji:
2015
Wydawca:
ADVSEO
Tematy:
adsorpcja
żel krzemionkowy
woda
chłodzenie adsorpcyjne
poprawa transferu ciepła i masy
adsorption
silica gel
water
adsorption chilling
heat and mass transfer enhancement
Opis:
This paper presents the results of studies on the enhancement of heat and mass transfer in an adsorber which is the main element of an adsorption chiller. A silica gel/water adsorption pair was examined. Experimental studies that refer to adsorption dynamics in a layer of silica gel covering directly the heat exchanger pipe were performed. Adsorption was conducted under different process conditions. Gas flow rate and size of grains were changed. Breakthrough curves and temperature changes with time were determined.
Źródło:
Technical Issues; 2015, 3; 25-32
2392-3954
Pojawia się w:
Technical Issues
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical study of the heat transfer and pressure drop in triangular chevron channels
Autorzy:
Dolatabadi, H.
Aghdam, A. H.
Powiązania:
https://bibliotekanauki.pl/articles/949298.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
heat transfer
pressure drop
thermal enhancement factor
phase shift
Opis:
Experimental and Numerical studies were carried out on turbulent heat transfer and friction factor loss through a triangular chevron channel. For uniform wall heat flux equal 1350 (W/m²) using air as a working fluid. Reynolds number varied from 3000 to 10000, phase shifted at the range of 0≤ϕ≤180, with variation distance between chevron surfaces (5 ≤ D ≤ 35 mm). Nu increased and TEF decreased in increasing of Re. The TEF and Nu increased with closing to channel phase shift angle 90˚, the best performance was noticed on phase shift, ϕ=90º. At the end of this paper effect of distance between chevron surfaces presented, The TEF and Nu increased with decreasing to channel distance and the best performance was noticed on closing to D=5(mm).
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 3; 751-763
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Conjugate Heat Transfer in Electromagnetic Liquid Metal Dream Pipe
Autorzy:
Puvaneswari, P.
Shailendhra, K.
Powiązania:
https://bibliotekanauki.pl/articles/140031.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
enhancement of heat transfer
dream pipe
conjugate heat transfer
laminar flow
oscillatory flow
hydromagnetic flow
liquid metals
zwiększenie przepływu ciepła
rura typu dream-pipe
sprzężona wymiana ciepła
przepływ laminarny
przepływ oscylacyjny
przepływ hydromagnetyczny
metale ciekłe
Opis:
The combined effect of conjugation, external magnetic field and oscillation on the enhancement of heat transfer in the laminar flow of liquid metals between parallel plate channels is analyzed. In order to make our results useful to the design engineers, we have considered here only the wall materials that are widely employed in liquid metal heat exchangers. Indeed, all the results obtained through this mathematical investigation are in excellent agreement with the available experimental results. The effective thermal diffusivity κe is increased by 3 · 106 times due to oscillation and that the heat flux as high as 1.5 · 1010 (W/m2) can be achieved. Based on our investigation, we have recommended the best choice of liquid metal heat carrier, wall material and its optimum thickness along with the optimum value of the frequency to maximize the heat transfer rate. At the optimum frequency, by choosing a wall of high thermal conductivity and optimum thickness, an increase of 19.98% in κe can be achieved. Our results are directly relevant to the design of a heat transfer device known as electromagnetic dream pipe which is a very recent development.
Źródło:
Archive of Mechanical Engineering; 2017, LXIV, 3; 375-399
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-13 z 13

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies