CFD-Based Study of Velocity and Temperature Distribution among Rib-Tube in Heat Environment

2014 ◽  
Vol 487 ◽  
pp. 558-561
Author(s):  
Su Hou De ◽  
Zhang Yu Fu ◽  
Che Ji Yong ◽  
Wu Shi Lei ◽  
Xiao Long Wen

The velocity distribution coupled thermal and fluid flow a rib-tube was studied in this article. Based on theory analysis and numerical simulation, we choose modal and wall function to simulate the flow in rib-tube, velocity to definite the dispersed phase. The governing equations were built and solved by numerical way. The progress of flow and heat exchange in rib-tube, the rules and contours of temperature, velocity were obtained, they shows that, along the rib-tube, velocity was changed with the temperature rising , which could give us a reference for engineering application .

2013 ◽  
Vol 483 ◽  
pp. 162-165
Author(s):  
Su Hou De ◽  
Zhang Yu Fu ◽  
Ji Yong Che ◽  
Xiao Long Wen

The flow of liquefied natural gas (LNG) which was coupled between heat transfer and fluid-flow in rib-tube was studied in this paper. Based on theoretical analysis, the model and wall-function were chosen to simulate the flow field of rib-tube, and the multiphase flow was described by the mixture model, in which the dispersed phase was defined by different velocity. In addtion, self-defining functions were used and governing equations were set up to solve the dispersed phase, and the result were compared with the experiment. The process of fluid-flow and heat exchange on rib-tube was simulated, and the contours of temperature, pressure, velocity, gas fraction were obtained, which showed that, the parameters of above changed when the temperature was rising and the LNG evaporating along the rib-tube, and a mixed process existed in the middle of the heat tube.


2011 ◽  
Vol 130-134 ◽  
pp. 1686-1690 ◽  
Author(s):  
De Qi Peng ◽  
Wei Qiang Wang ◽  
Tian Lan Yu ◽  
Biao Wei ◽  
Yu Zhou ◽  
...  

For solving cleaning fouling online for shell-and-tube heat exchanger,an asymmetric spiral-gear cleaning technology is presented. The RNGk-εturbulent model is used to simulate the fluid flow and heat transfer of the tube with the spiral-gear. Its velocity and turbulent intensity field, convection heat transfer characteristic and resistance property are analyzed. Numerical simulation results shows that radial velocity is larger in the annular area near the tube wall than that in the smooth tube. Tangential velocity in the diameter area corresponding to the width of spiral-gear insertion increases with radius,but it decreases with radius in the annular clearance between the insert and the tube wall. However, fluid tangential motion of the smooth tube is only stochastic,and its tangential velocity is lower several orders of magnitude than that for the tube with the insertions. The average surface heat transfer coefficient of the spiral-gear-inserted tube wall is increased nearly 88% than that from the smooth tube wall. In addition, the pressure drop caused by spiral-gear inserts is in the permissible range of engineering application. The inserts is applicable to the heat exchangers at a flow rate lower than 0.8 m·s-1.


Author(s):  
Takao Koshimizu ◽  
Hiromi Kubota ◽  
Yasuyuki Takata ◽  
Takehiro Ito

The working principle of refrigeration in basic pulse-tube refrigerators (BPTR) has been explained by the mechanism called surface heat pumping (SHP) that heat is conveyed from the cold end to the hot end of the pulse tube by the successive heat exchange between the working gas and the wall. In this study, a numerical simulation has been performed to clarify the effect of the wall in BPTRs by comparing the numerical results in two physical models; one is the model considering the heat exchange between the working gas and the wall (HE model), and the other is the model ignoring that (AW model). As a result, the importance in the effect of the wall was shown clearly. In addition, the mechanism of refrigeration other than the SHP was made clear in the AW model.


2012 ◽  
Vol 562-564 ◽  
pp. 1213-1217
Author(s):  
Feng Tian ◽  
Zhen Bin Gao ◽  
Yi Cai Sun

A flow sensor for liquids, based on the principle of fluid-structure heat transfer is presented. The heater and thermistor are integrated and wrapped together as a detector and heat source, allowing heat exchange between the sensor and the fluid. Through numerical simulation, the temperature distribution of the sensor was investigated, under conditions of various flow velocities. The process of turbulent heat transfer in the flow pipe was simulated, the temperature distribution in the sensor was analyzed and compared under different temperature and velocity of the fluid, and the corresponding measuring ranges were determined. The flow detection circuit is designed and the results of water flow velocity tests in the range of (0.01–1)m/s are presented.


2013 ◽  
Vol 291-294 ◽  
pp. 1969-1974
Author(s):  
Wei Liang Cheng ◽  
An Di ◽  
Li Chao Liu ◽  
Lian Guang Liu

The fouling in the heat transfer devices of power plants, not only changes the fluid flow state designed, but also counteracts the heat transfer, so the equipment safety and economy are reduced. The adsorption and deposition about fouling is a quite complicated chemical and physical process, and it is difficult to obtain an accurate and reasonable model and its engineering application. Therefore, under some different conditions such as velocity, temperature and concentration of fouling and pipe position, the numerical simulation is obtained in the power plant steam cooler. The temperature inside the pipe is gradually decreased with the velocity. At the same time, the fouling increases in the first half of the exchanger pipe, and easily appears near regions of entrance more and more. The fouling may occurs at the outlet position of the heat exchange tube. Under the same conditions the heat exchange tube near centre line is easier to bring the fouling.


2019 ◽  
Vol 286 ◽  
pp. 08004
Author(s):  
B. Jamal ◽  
M. Boukendil ◽  
A. Abdelbaki ◽  
Z. Zrikem

The present study aims to investigate coupled heat transfer by natural convection and conduction through a concrete hollow brick. The governing equations for conservation of mass, momentum and energy are discretized by the finite volume approach and solved by the SIMPLE algorithm. The numerical simulations were conducted to investigate the effect of Rayleigh number (103≤ Ra ≤ 107) on the heat transfer and fluid flow within the structure.


2014 ◽  
Vol 487 ◽  
pp. 290-293
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Steven Taniselass ◽  
Nor Shakirina Nadzri ◽  
Tan Hsio Mei ◽  
...  

Recently, microfluidics system has been widely employed in various areas for instance biomedical,pharmaceuticals and cell biological researchdue to its advantages. The flow behavior in microchannels with different cross-sections has been topic in previous studies. In this paper, numerical simulation of fluid flow in Forward Facing Step (FFS) configuration was performed to investigate velocity profile after the step. Reynolds numbers (Re) 100 with different step heights, 1μm and 3μm were used to observe trend occurs in the flow characteristics. The result illustrated an increase of velocity distribution with the increase of the step height.


Sign in / Sign up

Export Citation Format

Share Document