Browsing by Author "Wang, KN"

Now showing 1 - 5 of 5

An investigation of a block moving back and forth on a heat plate under a slot jet
(2001-07-01)
Fu, WS
;
Wang, KN
;
Ke, WW
;
機械工程學系
;
Department of Mechanical Engineering
An investigation of heat transfer rate of a heat plate under a slot jet was studied numerically. For enhancing the heat transfer rate of the heat plate, a block moves back and forth on the heat plate. Then the thermal boundary layer on the heat plate is destroyed by the moving block and a new thermal boundary layer reforms immediately as the block passes through. Consequently, the remarkable heat transfer enhancement of the heat plate is attained. This subject belongs to a kind of moving boundary problems, the modified arbitrary Lagrangian Eulerian (ALE) method is suitable for solving this subject. The results show that the maximum increment of heat transfer rate is about 200% in the largest velocity case. (C) 2001 Elsevier Science Ltd. All rights reserved.
An investigation of a block moving back and forth on a heat plate under a slot jet. Part II (the effects of block moving distance and vacant distance)
(2001-12-01)
Fu, WS
;
Wang, KN
;
機械工程學系
;
Department of Mechanical Engineering
A continuous investigation of a block moving back and forth on a heat plate under a slot jet was studied numerically. This study investigates the effects of block moving distance and vacant distance between the block and heat plate on the heat transfer of heat plate. This subject belongs to a kind of moving boundary problems, and the modified Arbitrary Lagrangian Eulerian (ALE) method is suitable for solving this subject. The results show that the increment of the heat transfer rate of heat plate is not direct proportion to the block moving distance, and the smaller vacant distance is expected for obtaining the larger heat transfer rate of heat plate. (C) 2001 Elsevier Science Ltd. All rights reserved.
Effect of moving distance of a moving block on heat transfer in a channel flow
(2001-04-01)
Fu, WS
;
Chen, SF
;
Wang, KN
;
機械工程學系
;
Department of Mechanical Engineering
A numerical investigation of heat transfer rate of an insulated block moving on a heated surface in a channel was studied. The study mainly investigated the effect of block moving distance on the heat transfer rate of heated surface. This subject belongs to a kind of moving boundary problems, and the modified Arbitrary Lagrangian Eulerian method is suitable for solving this subject. The results show that the block moving distance affects the flow and thermal fields remarkably. The heat transfer rate of heated surface increases proportionally to the increment of the block moving distance, when the block moving distance is larger than a critical value. (C) 2001 Elsevier Science Ltd.
Heat transfer of porous medium with random porosity model in a laminar channel flow
(2001-07-01)
Fu, WS
;
Wang, KN
;
Ke, WW
;
機械工程學系
;
Department of Mechanical Engineering
In this paper, force convection heat transfer of a porous medium in a laminar channel flow is numerically investigated. The porous medium with random porosities is used to enhance heat transfer and the random porosities are derived by the Kinderman-Ramage procedure. The results show that when the mean porosity is larger than 0.5, the average Nusselt numbers are enhanced and better than the solid block case. Therefore, a porous medium with larger porosity and the proper bead diameter could provide more heat dissipation. For the random porosity distribution, the profiles of velocities are disordered and the channeling effect is not apparent near the plate region.
Laminar forced convection in a channel with a moving block
(2001-07-01)
Fu, WS
;
Ke, WW
;
Wang, KN
;
機械工程學系
;
Department of Mechanical Engineering
Heat transfer rate in a channel with an insulated moving block on a heated surface was studied numerically. For enhancing the heat transfer rate of the heated surface, the block moves back and forth on the heated surface. Then the thermal boundary layer attached to the heated surface is destroyed by the moving block and a new thermal boundary layer reforms immediately as the block passes through. Consequently, a remarkable heat transfer enhancement of the heated surface is attained. This subject belongs to a kind of moving boundary problems, and the modified Arbitrary Lagrangian Eulerian method is suitable for solving this subject. The results show that the maximum increment of heat transfer rate is about 98% in the study. (C) 2001 Elsevier Science Ltd. All rights reserved.