Enhanced Heat Transfer Using Porous Carbon Foam in Cross Flow—Part I: Forced Convection

2006 ◽  
Vol 129 (6) ◽  
pp. 735-742 ◽  
Author(s):  
Yorwearth L. Jamin ◽  
Abdulmajeed A. Mohamad
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Carbon Foam ◽  
Industrial Processes ◽  
Transfer Enhancement ◽  
Vertical Pipe ◽  
Enhanced Heat Transfer ◽  
Flow Part

Cogeneration of heat and power has become standard practice for many industrial processes. Research to reduce the thermal resistance in heat exchangers at the gas/solid interface can lead to greater energy efficiency and resource conservation. The main objective of this experimental study is to quantify and compare the heat transfer enhancement of carbon foam and aluminum fins. The study measures the heat transfer rate and pressure drop from a heated vertical pipe, with and without porous medium, in forced convection. The largest increase in Nusselt number was achieved by aluminum fins, which was about three times greater than the best carbon foam case.

scholarly journals Diamond-Shaped Extended Fins for Heat Transfer Enhancement in a Double-Pipe Heat Exchanger: An Innovative Design

2021 ◽  
Vol 11 (13) ◽  
pp. 5954
Author(s):  
Muhammad Ishaq ◽  
Amjad Ali ◽  
Muhammad Amjad ◽  
Khalid Saifullah Syed ◽  
Zafar Iqbal
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Adaptive Finite Element Method ◽  
Transfer Enhancement ◽  
Enhanced Heat Transfer ◽  
Frictional Loss ◽  
Special Cases ◽  
Double Pipe ◽  
Pipe Heat

Heat transfer enhancement in heat exchangers results in thermal efficiency and energy saving. In double-pipe heat exchangers (DPHEs), extended or augmented fins in the annulus of the two concentric pipes, i.e., at the outer surface of the inner pipe, are used to extend the surface of contact for enhancing heat transfer. In this article, an innovative diamond-shaped design of extended fins is proposed for DPHEs. This type of fin is considered for the first time in the design of DPHEs. The triangular-shaped and rectangular-shaped fin designs of DPHE, available in the literature, can be recovered as special cases of the proposed design. An h-adaptive finite element method is employed for the solution of the governing equations. The results are computed for various performance measures against the emerging parameters. The results dictate that the optimal configurations of the diamond-shaped fins in the DPHE for an enhanced heat transfer are recommended as follows: If around 4–6, 8–12, or 16–32 fins are to be placed in the DPHE, then the height of the fins should be 20%, 80%, or 100%, respectively, of the annulus width. If frictional loss of heat is also to be considered, then for fin-heights of 20–80% and 100% of the annulus width, the placement of 4 and 8 diamond-shaped fins, respectively, is recommended for an enhanced heat transfer. These recommendations are for the radii ratio (i.e., the ratio of the inner pipe radius to that of the outer pipe) of 0.25. The recommendations are be modified if the radii ratio is altered.

Heat transfer enhancement using alumina and fly ash nanofluids in parallel and cross-flow concentric tube heat exchangers

2016 ◽  
Vol 89 (3) ◽  
pp. 414-424 ◽  
Author(s):  
Adnan Sözen ◽  
H. İbrahim Variyenli ◽  
M. Bahadır Özdemir ◽  
Metin Gürü ◽  
İpek Aytaç
Keyword(s):  
Heat Transfer ◽  
Fly Ash ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Transfer Enhancement

scholarly journals Heat Transfer Enhancement by Using Porous Heat Exchangers

2018 ◽  
Vol 7 (1) ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Exchangers ◽  
Power Conversion ◽  
High Heat ◽  
Heat Fluxes ◽  
Transfer Enhancement ◽  
Enhanced Heat Transfer ◽  
Economic Competitiveness ◽  
Energy Technologies

Effective heat transfer is essential in a variety of energy technologies in order to enable the maximum possible power density and power conversion efficiency needed for economic competitiveness and fuel conservation. The goal of enhanced heat transfer is to encourage or accommodate high heat fluxes. This results in reduction of heat exchanger size, which generally leads to less capital cost. Recently tremendous works have been conducted on heat transfer enhancement and a large number of techniques for heat transfer enhancement have been developed. This work concerns the investigation on effect of porous media on heat transfer rate in heat exchangers.

Numerical Investigations Of The Thermal Characteristics Of A Flip-Chip BGA Package With And Without Heat Sink

2004 ◽  
Vol 1 (3) ◽  
pp. 127-135
Author(s):  
Meng-Jen Wang ◽  
Chao-An Lin
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Heat Sink ◽  
Flip Chip ◽  
Cross Flow ◽  
Thermal Characteristics ◽  
Transfer Enhancement ◽  
Numerical Investigations ◽  
Bga Package ◽  
Cross Flow Velocity

The thermal characteristics of a flip-chip BGA package on board are numerically investigated under both natural and forced convection conditions. The possible heat transfer enhancement strategy using heat sink is also addressed. Heat generated at the junction could transfer in the upward and downward (through PCB) directions of the package, and then be dissipated to the ambient by both convection and radiation. For the cases without heat sink, the amount of the heat dissipated through the PCB comprises 90% and 75% of the power generated for the natural and forced convection regimes, respectively. With the proper heat sink attached the rate of the upward heat transfer increases and can reach 50% of the power dissipated under the forced convection condition. Detailed analysis is presented regarding the effects of the cross flow velocity, the number of fins and the height of the heat sink on the thermal resistance of the flip-chip BGA package.

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