Optimal Heating Algorithm for the Three-Dimensional Forced-Convection Problems

2003 ◽  
Vol 17 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Cheng-Hung Huang ◽  
Chun-Yu Li
Keyword(s):  
Forced Convection ◽  
Three Dimensional ◽  
Optimal Heating

Three-Dimensional Forced Convection in Plane Symmetric Sudden Expansion

2004 ◽  
Vol 126 (5) ◽  
pp. 836-839 ◽  
Author(s):  
J. H. Nie and ◽  
B. F. Armaly
Keyword(s):  
Nusselt Number ◽  
Forced Convection ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Flow Region ◽  
Outer Edge ◽  
Sudden Expansion ◽  
Recirculation Flow ◽  
Plane Symmetric ◽  
Laminar Forced Convection

Simulations of three-dimensional laminar forced convection in a plane symmetric sudden expansion are presented for Reynolds numbers where the flow is steady and symmetric. A swirling “jetlike” flow develops near the sidewalls in the separating shear layer, and its impingement on the stepped wall is responsible for the maximum that develops in the Nusselt number adjacent to the sidewalls and for the reverse flow that develops in that region. The maximum Nusselt number on the stepped wall is located inside the primary recirculation flow region and its location does not coincide with the jetlike flow impingement region. The results reveal that the location where the streamwise component of wall shear stress is zero on the stepped walls does not coincide with the outer edge of the primary recirculation flow region near the sidewalls.

LAMINAR FORCED CONVECTION IN THREE-DIMENSIONAL DUCT FLOWS

1988 ◽  
Vol 13 (4) ◽  
pp. 451-466 ◽  
Author(s):  
C. Nonino ◽  
S. Del Giudice ◽  
G. Comini
Keyword(s):  
Forced Convection ◽  
Three Dimensional ◽  
Laminar Forced Convection

Grounded Electrode Size Effect on Forced Convection Enhancement by a Single Stage EHD Gas Pump

2019 ◽  
Author(s):  
A. K. M. Monayem H. Mazumder
Keyword(s):  
Forced Convection ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Single Stage ◽  
Temperature Fields ◽  
Power Requirement ◽  
Maximum Increase ◽  
Square Channel ◽  
Wide Range ◽  
Volume Method

Abstract In this study, forced convection enhancement in a square channel by a single stage electrohydrodynamic (EHD) gas pump is numerically examined. The EHD gas pump having three different sizes of grounded electrode configurations: 0.5-inch, 1-inch, and 2-inch wide respectively are investigated for their effectiveness in the enhancement of forced convection and pumping power requirement. The EHD gas pump with 28 emitting electrodes is evaluated for a wide range of operating voltages starting from 20 kV up to 28 kV. The influence of electric field on the flow and temperature fields is also examined for a wide range of Reynolds numbers. The three-dimensional governing equations for the flow and temperature fields are solved using the finite volume method. The Reynolds numbers (Re) considered in this study varies in a range between 100 and 2000. At Re = 100, a maximum increase of 55% in the average Nusselt number is achieved with an applied voltage of 28 kV. The overall effectiveness of the EHD gas pump in heat transfer enhancement is evaluated by the thermal hydraulic performance parameter, (Nu/Nu0)/(f/f0), which is always greater than unity. These results disclose that EHD technique has a great potential for many engineering applications, particularly for thermal management.

Role of Three-Dimensional Swirl in Forced Convection Heat Transfer Enhancement in Wavy-Plate-Fin Channels

2022 ◽  
Author(s):  
Dantong Shi ◽  
Kuan-Ting Lin ◽  
Milind A. Jog ◽  
Raj M. Manglik
Keyword(s):  
Heat Transfer ◽  
Aspect Ratio ◽  
Forced Convection ◽  
Three Dimensional ◽  
Local Heat Transfer ◽  
Swirl Flow ◽  
Channel Height ◽  
Wave Trough ◽  
Spacing Ratio ◽  
Fin Spacing

Abstract The influence of swirl flow on enhanced forced convection in wavy-plate-fin cores has been investigated. Three-dimensional computational simulations were carried out for steady-state, periodically developed flow of air (Pr ~ 0.71) with channel walls subject to constant-uniform temperature and flow rates in the range 50 = Re = 4000. The recirculation that develops in the wall troughs and grows to an axial helix is scaled by the Swirl number Sw. As Sw increases, tornado-shaped vortices appear in the wave trough region mid-channel height, then extend longitudinally to encompass majority of the flow channel. As shown by the local wall-shear and heat transfer coefficient variations, the boundary-layer thinning upstream of the wave peak assists to intensify the momentum and heat transfer. However, the flow recirculation in wave trough impedes the local heat transfer at low Sw due to flow stagnation but promotes it at high Sw because of swirl-augmented fluid mixing. Swirling flows also create pressure drag that contributes substantively to the overall pressure loss. Its proportion grows as Sw, corrugation severity, and fin spacing increases to as much as 80% of the total pressure drop. The fin-wall curvature-induced secondary circulation nevertheless produces significantly enhanced convection, and more so in flows with higher Sw. It is quantified by Ff (or j), which is seen to increase log-linearly as fin corrugation aspect ratio and/or fin spacing ratio increases; the influence of cross-section aspect ratio is found to be marginal.

Forced convection in three-dimensional flows: II. Asymptotic solutions for mobile interfaces

AIChE Journal ◽  
1970 ◽  
Vol 16 (5) ◽  
pp. 771-786 ◽  
Author(s):  
W. E. Stewart ◽  
J. B. Angelo ◽  
E. N. Lightfoot
Keyword(s):  
Forced Convection ◽  
Three Dimensional ◽  
Asymptotic Solutions ◽  
Mobile Interfaces
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