Revisiting the influence of artificial roughness shapes on heat transfer enhancement

2022 ◽  
Author(s):  
Anil Singh Yadav ◽  
Anirudh Gattani
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Artificial Roughness ◽  
Transfer Enhancement

Use of artificial roughness to enhance heat transfer in solar air heaters – a review

2010 ◽  
Vol 21 (1) ◽  
pp. 35-51 ◽  
Author(s):  
Thakur Sanjay Kumar ◽  
N.S. Thakur ◽  
Anoop Kumar ◽  
Vijay Mittal
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Hydraulic Performance ◽  
Solar Air Heater ◽  
Artificial Roughness ◽  
Transfer Enhancement ◽  
Air Heater ◽  
Roughness Elements

Improvement in the thermo hydraulic performance of a solar air heater can be done by enhancing the heat transfer. In general, heat transfer enhancement techniques are divided into two groups: active and passive techniques. Providing an artificial roughness on a heat transferring surface is an effective passive heat transfer technique to enhance the rate of heat transfer to fluid flow. In this paper, reviews of various artificial roughness elements used as passive heat transfer techniques, in order to improve thermo hydraulic performance of a solar air heater, is done. The objective of this paper is to review various studies, in which different artificial roughness elements are used to enhance the heat transfer rate with little penalty of friction. Correlations developed by various researchers with the help of experimental results for heat transfer and friction factor for solar air heater ducts by taking different roughened surfaces geometries are given in tabular form. These correlations are used to predict the thermo hydraulic performance of solar air heaters having roughened ducts. The objective is to provide a detailed review on heat transfer enhancement by using an artificial roughness technique. This paper will be very helpful for the researchers who are researching new artificial roughness for solar air heater ducts to enhance the heat transfer rate and comparing with artificial roughness already studied by various researchers.

Heat Transfer Enhancement by Artificial Roughness at Reynolds Numbers Related With Laminar and Transitional Regimes for High-Viscous Liquids

2010 ◽  
Author(s):  
Mikhail A. Gotovsky ◽  
Sergey A. Isaev
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Reynolds Numbers ◽  
High Heat ◽  
Artificial Roughness ◽  
Transfer Enhancement ◽  
Reynolds Analogy ◽  
Transition Range ◽  
Viscous Liquids ◽  
High Heat Transfer

Artificial roughness (AR) formed by annular rolling or dimpling is one of the most well-known examples of Reynolds analogy (RA) breaking in a favor of heat transfer. Surfaces which can be called ARPD - Artificial Roughness, are manufactured by wall Pressure Deformation. ARPD surfaces have some similar thermal hydraulic properties which permit to unite them in the common group. General characteristics of ARPD surfaces are considered here. But the main attention is paid to such surface performance for coolants with high Prandtl numbers. It is important that Reynolds numbers must be close sufficiently to its critical value for smooth tube. Some experimental data show that extremely high heat transfer enhancement ratio can be obtained under such conditions for substantially less pressure loss ratio increase. Similar qualitative results obtained for several types of ARPD — dimpled, annular rolled and spirally corrugated tubes — are demonstrated. These results are related partially with critical Reynolds number decrease and partially with specific character of heat transfer evolution in laminar–turbulent transition range for high-viscous liquids. Such enhancement method can be used effectively for heat exchangers with high-viscous liquids (oils, for example).

Numerical Investigation and Thermal Transfer on a Wall Corrugated without and with Artificial Roughness

2019 ◽  
Vol 392 ◽  
pp. 189-199
Author(s):  
Rabia Ferhat ◽  
Ahmed Zine Dinne Dellil ◽  
M. Kamal Hamidou
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Exchange ◽  
Heat Transfer Enhancement ◽  
Turbulent Flows ◽  
Exchange Process ◽  
Three Dimensional ◽  
Artificial Roughness ◽  
Transfer Enhancement ◽  
Corrugated Channel

The objective of this study is to give the designer an appreciation of the heat transfer enhancement in turbulent flows through corrugated channels in a heat plate exchanger. Precisely, the influence of a new technic named the artificial roughness is probed on corrugated walls, with their variable wall amplitudes for assessing the effectiveness of the heat exchange. For that purpose, a numerical simulation approach is adopted. The rectangular, triangular, trapezoidal and sinusoidal corrugated wall and artificial roughness wall shapes are investigated, in order to determine the optimal wall profile resulting in significance increase in the heat exchange process with a minimum friction loss. The numerical results are presented in the form of isotherms, streamlines, contour, Nusselt number (Nu) and friction coefficient (Cf) using commercial software ANSYS- Fluent where the Reynolds number is in the range from 3 000 to 12 000. Our simulations reveal that the sinusoidal-corrugated channel has the highest heat transfer enhancement followed by rectangular, triangular and trapezoidal-corrugated channel. In addition, introduction of artificial roughness in the wavy channel induces stronger secondary flow which makes the flow three-dimensional and improve the heat transfer by a maximum 40% at a Reynolds number equal to 12 000. This may indicate benefits for designing heat plate compact exchangers capable of higher performances in the turbulent flow regimes.

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