The Effect of Jet Angle and Initial Plate Temperature during Jet Impingement Heat Transfer Process in Ultra-Fast Cooling Technology

2014 ◽  
Vol 86 (5) ◽  
pp. 489-494 ◽  
Author(s):  
Qian Xie ◽  
Bingxing Wang ◽  
Zhaodong Wang ◽  
Guodong Wang
2015 ◽  
Vol 816 ◽  
pp. 775-780
Author(s):  
Jian Hui Shi ◽  
Jin Hua Zhao ◽  
Guo Yuan ◽  
Lian Yun Jiang ◽  
Kun Zhao ◽  
...  

As for the impinging jets of single group slot nozzles, the heat transfer of the top and bottom strip surface is uneven which is mainly caused by the various jet distances of the top and bottom nozzle to the strip surface and the effect of gravity. In this study, the convective heat transfer process of the top and bottom strip surface due to single group slot nozzles in the ultra-fast cooling (UFC) system was studied by the fluid-structure interaction finite element method. The distributions of the flow field and heat transfer for the top and bottom strip surfaces were obtained under the various parameters. The results showed that, the difference value of the average Nusselt numbe for the top and bottom strip surface was decreased with the increase of the jet velocity, but when the jet velocity was up to 5m/s it remained almost the same. The uniformity of the top and bottom surface was improved by the jet impingement height (h) for the h<45mm. It was found that for h=25mm, the heat transfers of the top and down surfaces were more evenly, and the different value of average Nusselt number for the decreased by about 12.6%-28% as the jet impingement height increased from 25mm to 45mm when the slot width was 5mm.


2011 ◽  
Vol 312-315 ◽  
pp. 477-482 ◽  
Author(s):  
Pey Shey Wu ◽  
Yi Wen Lo ◽  
Fong Chia Cheng

The enhancement of impingement heat transfer on a flat plate covered with a thick layer of porous medium with or without a center hole was numerically investigated. The renormalization group turbulence model is selected for the fluid region while Forchheimer extended Darcy’s model is used for porous region. The numerical models were justified by comparisons with available experimental data. Computational results show that an attached porous medium with a center hole can effectively enhance jet impingement heat transfer while an attached thick porous layer without a center hole has detrimental effect. The physics of these results are supported and well explained by the detailed flow patterns. The most influential parameters in this heat transfer process include the jet Reynolds number and the center hole geometry (hole depth and jet-to-hole diameter ratio). A good hole geometry should well trap the jet and direct the coolant along the heated plate.


2020 ◽  
Vol 786 (11) ◽  
pp. 30-34
Author(s):  
A.M. IBRAGIMOV ◽  
◽  
L.Yu. GNEDINA ◽  

This work is part of a series of articles under the general title The structural design of the blast furnace wall from efficient materials [1–3]. In part 1, Problem statement and calculation prerequisites, typical multilayer enclosing structures of a blast furnace are considered. The layers that make up these structures are described. The main attention is paid to the lining layer. The process of iron smelting and temperature conditions in the characteristic layers of the internal environment of the furnace is briefly described. Based on the theory of A.V. Lykov, the initial equations describing the interrelated transfer of heat and mass in a solid are analyzed in relation to the task – an adequate description of the processes for the purpose of further rational design of the multilayer enclosing structure of the blast furnace. A priori the enclosing structure is considered from a mathematical point of view as the unlimited plate. In part 2, Solving boundary value problems of heat transfer, boundary value problems of heat transfer in individual layers of a structure with different boundary conditions are considered, their solutions, which are basic when developing a mathematical model of a non-stationary heat transfer process in a multi-layer enclosing structure, are given. Part 3 presents a mathematical model of the heat transfer process in the enclosing structure and an algorithm for its implementation. The proposed mathematical model makes it possible to solve a large number of problems. Part 4 presents a number of examples of calculating the heat transfer process in a multilayer blast furnace enclosing structure. The results obtained correlate with the results obtained by other authors, this makes it possible to conclude that the new mathematical model is suitable for solving the problem of rational design of the enclosing structure, as well as to simulate situations that occur at any time interval of operation of the blast furnace enclosure.


2003 ◽  
Author(s):  
B. X. Wang ◽  
H. Li ◽  
X. F. Peng ◽  
L. X. Yang

The development of a numerical model for analyzing the effect of the nano-particles’ Brownian motion on the heat transfer is described. By using the Maxwell velocity distribution relations to calculate the most possible velocity of fluid molecules at certain temperature gradient location around the nano-particle, the interaction between fluid molecules and one single nano-particle is analyzed and calculated. Based on this, a syntonic system is proposed and the coupled effect that Brownian motion of nano-particles has on fluid molecules is simulated. This is used to formulate a reasonable analytic method, facilitating laboratory study. The results provide the essential features of the heat transfer process, contributed by micro-convection to be considered.


2011 ◽  
Vol 393-395 ◽  
pp. 412-415
Author(s):  
Jian Hua Zhong ◽  
Li Ming Jiang ◽  
Kai Feng

In this article, finned copper tube used in the central air conditioning was acted as the discussed object. According to the combination with actual processing and theoretical calculations, Five finned tube was selected with typical structural parameters, and established their entity model using Pro/E, then the heat transfer process of finned tube was simulated through the ANSYS, the effect of the fin height, fin thickness and other structure parameters to the heat transfer enhancement of finned tube was researched. Meantime the efficiency of the heat transfer under different convection heat transfer coefficient was also studied.


2011 ◽  
Vol 228-229 ◽  
pp. 676-680 ◽  
Author(s):  
Ye Tian ◽  
Xun Liang Liu ◽  
Zhi Wen

A three-dimensional mathematic model is developed for a 100kw single-end recuperative radiant tube and the simulation is performed with the CFD software FLUENT. Also it is used to investigate the effect of distance between combustion chamber exit and inner tube on heat transfer process. The results suggest that the peak value of combustion flame temperature drops along with the increasing of distance, which leads to low NOX discharging. Also radiant tube surface bulk temperature decreases, which causes radiant tube heating performance losses.


Sign in / Sign up

Export Citation Format

Share Document