Heat transfer in the irregular porous structures

2002 ◽  
Author(s):  
Boris M. Galitseisky
Keyword(s):  
Heat Transfer ◽  
Porous Structures

MICROSCALE TWO PHASE HEAT TRANSFER ENHANCEMENT IN POROUS STRUCTURES

Equipment ◽  
2006 ◽  
Author(s):  
Leonid L. Vasiliev ◽  
A. Zhuravlyov ◽  
A. Shapovalov ◽  
L. L. Vasiliev, Jr
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Porous Structures ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Two Phase Heat Transfer

Enhanced Heat Transfer Using Microporous Copper Inverse Opals

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Hyoungsoon Lee ◽  
Tanmoy Maitra ◽  
James Palko ◽  
Daeyoung Kong ◽  
Chi Zhang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Pore Diameter ◽  
Bubble Formation ◽  
Copper Surface ◽  
Porous Structures ◽  
Inverse Opals ◽  
Optical Images ◽  
Nucleation Sites ◽  
Enhanced Boiling

Enhanced boiling is one of the popular cooling schemes in thermal management due to its superior heat transfer characteristics. This study demonstrates the ability of copper inverse opal (CIO) porous structures to enhance pool boiling performance using a thin CIO film with a thickness of ∼10 μm and pore diameter of 5 μm. The microfabricated CIO film increases microscale surface roughness that in turn leads to more active nucleation sites thus improved boiling performance parameters such as heat transfer coefficient (HTC) and critical heat flux (CHF) compared to those of smooth Si surfaces. The experimental results for CIO film show a maximum CHF of 225 W/cm2 (at 16.2 °C superheat) or about three times higher than that of smooth Si surface (80 W/cm2 at 21.6 °C superheat). Optical images showing bubble formation on the microporous copper surface are captured to provide detailed information of bubble departure diameter and frequency.

Parametric Study of Rarefaction Effects on Micro- and Nanoscale Thermal Flows in Porous Structures

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
A. H. Meghdadi Isfahani
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Knudsen Number ◽  
Porous Structures ◽  
Knudsen Flow ◽  
Wide Range ◽  
Microscale Flows ◽  
Boltzmann Method ◽  
Thermal Flows ◽  
Rarefaction Effects

Hydrodynamics and heat transfer in micro/nano channels filled with porous media for different porosities and Knudsen numbers, Kn, ranging from 0.1 to 10, are considered. The performance of standard lattice Boltzmann method (LBM) is confined to the microscale flows with a Knudsen number less than 0.1. Therefore, by considering the rarefaction effect on the viscosity and thermal conductivity, a modified thermal LBM is used, which is able to extend the ability of LBM to simulate wide range of Knudsen flow regimes. The present study reports the effects of the Knudsen number and porosity on the flow rate, permeability, and mean Nusselt number. The Knudsen's minimum effect for micro/nano channels filled with porous media was observed. In addition to the porosity and Knudsen number, the obstacle sizes have important role in the heat transfer, so that enhanced heat transfer is observed when the obstacle sizes decrease. For the same porosity and Knudsen number, the inline porous structure has the highest heat transfer performance.

Sign in / Sign up

Export Citation Format

Share Document