Effects of blade shape on heat transfer and resistance for a spiral flow in a tube

1976 ◽  
Vol 31 (2) ◽  
pp. 900-903
Author(s):  
A. F. Koval'nogov ◽  
V. P. Ermachenko
Keyword(s):  
Heat Transfer ◽  
Spiral Flow ◽  
Blade Shape

Effect of the Broken Rib Locations on the Heat Transfer and Fluid Flow in a Rotating Latticework Duct

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Wei Du ◽  
Lei Luo ◽  
Songtao Wang ◽  
Jian Liu ◽  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Shear Stress ◽  
Nusselt Number ◽  
Wall Shear Stress ◽  
Flow Structure ◽  
Suction Side ◽  
Spiral Flow ◽  
Numerical Studies ◽  
Rotational Number ◽  
Wall Shear

AbstractA numerical method was used to study the effect of the broken rib locations on the heat transfer and flow structure in the latticework duct with various rotational numbers. The latticework duct had eleven subchannels on both the pressure side and the suction side. The crossing angle for each subchannel was 45 deg. The numerical studies were conducted with five different broken rib locations and six rotational numbers (0–0.5). The Reynolds number was fixed as 44,000. The flow structure, wall shear stress, and Nusselt number distributions were analyzed. It was found that the upward spiral flow and helical flow dominated the flow structure in the latticework duct. In addition, the impingement region (at the beginning of the subchannel) induced by the upward spiral flow was responsible for the high Nusselt number and wall shear stress. After adoption of the broken rib in the latticework duct, the Nusselt number was increased by 6.12% on the pressure endwall surface and increased by 6.02% on the rib surface compared to the traditional latticework duct. As the rotational number was increased, the Nusselt number on the pressure endwall surface was decreased by up to 5.4%. However, the high rotational number enhanced the heat transfer on the suction side. The high rotational number also decreased the friction factor in the latticework duct. Furthermore, the overall thermal performance was increased by 12.12% after adoption of the broken ribs on both the turn region and the impingement region.

Heat transfer of hybrid nanofluid in a shell and tube heat exchanger equipped with blade-shape turbulators

2020 ◽  
Author(s):  
Aysan Shahsavar Goldanlou ◽  
Mohammad Sepehrirad ◽  
Mostafa Papi ◽  
Ahmed Kadhim Hussein ◽  
Masoud Afrand ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Hybrid Nanofluid ◽  
Tube Heat Exchanger ◽  
Blade Shape ◽  
Shell And Tube

F222 Natural Convection in a Horizontal Cylindrical Annulus : Heat Transfer and Flow Characteristics of 3-D Spiral Flow

2005 ◽  
Vol 2005 (0) ◽  
pp. 439-440
Author(s):  
Hiroyuki NAKAGAWA ◽  
Mamoru SENDA ◽  
Kyoji INAOKA
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flow Characteristics ◽  
Spiral Flow ◽  
Cylindrical Annulus

scholarly journals Effect of electro-osmosis and mixed convection on nano-bio-fluid with non-spherical particles in a curved channel

2018 ◽  
Vol 19 (1) ◽  
pp. 108 ◽  
Author(s):  
N. Ijaz ◽  
Ahmed Zeeshan ◽  
S.U. Rehman
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Base Fluid ◽  
Spherical Particles ◽  
Spherical Nanoparticles ◽  
Curved Channel ◽  
Blade Shape ◽  
Electro Osmosis ◽  
Flexible Walls ◽  
Aqueous Base

This paper resigns to study effects of electro-kinetic force due to presence of electrical charge layer on the walls of the channel. The nano-bio-fluid fills the void between two concentric curved plates. The flow is induced due to peristaltic wave on flexible walls. The effects of mixed convection along with heat transfer are accounted. Furthermore, the focus is on effects of shapes of non-spherical nanoparticles in nano-bio-fluid and its effects on the flow. Nanofluids are important in treatment of cancer and other diseases in tissues which are normally not reachable by normal drug procedures. The problem is modeled for four types of non-spherical nanoparticles of alumina in aqueous base fluid. Numerical solution is obtained using Mathematica. Some important results are displaced through graphs. Empirical observations display that a significantly greater velocity for nanofluid with blade shape particles is offered followed by brick shaped particles. Numerical experiment also deems a rise in heat transfer due to presence of blade shapes particles.

scholarly journals A221 Enhancement of forced convective boiling heat transfer using spiral flow for power modules

2014 ◽  
Vol 2014 (0) ◽  
pp. _A221-1_-_A221-2_
Author(s):  
Yuta Ichikura ◽  
Kazuya Kodani ◽  
Yuuki Tsukinari
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Spiral Flow ◽  
Convective Boiling ◽  
Power Modules

scholarly journals Numerical Simulation of Spiral Flow and Heat Transfer in Hydrate Pipeline With Long Twisted Band

2020 ◽  
Author(s):  
Yongchao Rao ◽  
Lijun Li ◽  
Shuli Wang ◽  
Shuhua Zhao ◽  
Shidong Zhou
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Field ◽  
Pipe Wall ◽  
Large Temperature ◽  
Heat Transfer Characteristics ◽  
Spiral Flow ◽  
Light Pipe ◽  
Transfer Characteristics ◽  
Straight Flow

Abstract The DPM model (discrete phase model) considering the motion of solid particles was used to simulate the complex spiral flow characteristics of hydrate in the pipe spinning up with long twisted band. The deposition and heat transfer characteristics of gas hydrate particles in the pipe spiral flow were studied. The velocity distribution, pressure drop distribution, heat transfer characteristics and particle settling characteristics of the flow field in the pipeline were investigated. The numerical results show that, compared with the straight flow of light pipe without twisted band, two obvious eddies are formed in the flow field under the spinning action of twisted band, and the velocities are maximum at the center of the eddies. Along the direction of the pipe, the two vortices move towards the pipe wall from near the twisted band, which can effectively carry the hydrate particles deposited on the pipe wall. With the same Reynolds number, the greater the twist ratio, the weaker the spiral strength, the smaller the tangential velocity of the spiral flow, and the smaller the pressure drop of the pipe. Therefore, the pressure loss can be reduced as much as possible while ensuring the spinning effect of the spiral flow. In a straight light pipe flow, the Nusser number is in a parabolic shape with the opening downwards. At the center of the pipe, the Nusser number gradually decreases towards the pipe wall at the maximum, and at the near wall, the attenuation gradient of Nu is large. For spiral flow, the curve presented by Nusserr number shows a trough at the center of the pipe and a peak at 1/2 of the pipe diameter. With the reduction of twist rate, the Nussel number becomes larger and larger. Therefore, the spiral flow can make the temperature distribution in the flow field in the pipeline more even, and prevent the large temperature difference resulting in the mass formation of hydrate particles in the pipeline wall. Spiral flow has a good carrying effect. Under the same working condition, the spiral flow carries hydrate particles at a distance about 3-4 times that of the straight flow.

scholarly journals Numerical Simulation Study on Flow Laws and Heat Transfer of Gas Hydrate in the Spiral Flow Pipeline with Long Twisted Band

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 489
Author(s):  
Yongchao Rao ◽  
Lijun Li ◽  
Shuli Wang ◽  
Shuhua Zhao ◽  
Shidong Zhou
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Pressure Drop ◽  
Gas Hydrate ◽  
Pipe Wall ◽  
Heat Transfer Characteristics ◽  
Natural Gas Hydrate ◽  
Spiral Flow ◽  
Transfer Characteristics ◽  
Straight Flow

The natural gas hydrate plugging problems in the mixed pipeline are becoming more and more serious. The hydrate plugging has gradually become an important problem to ensure the safety of pipeline operation. The deposition and heat transfer characteristics of natural gas hydrate particles in the spiral flow pipeline have been studied. The DPM model (discrete phase model) was used to simulate the motion of solid particles, which was used to simulate the complex spiral flow characteristics of hydrate in the pipeline with a long twisted band. The deposition and heat transfer characteristics of gas hydrate particles in the spiral flow pipeline were studied. The velocity distribution, pressure drop distribution, heat transfer characteristics, and particle settling characteristics in the pipeline were investigated. The numerical results showed that compared with the straight flow without a long twisted band, two obvious eddies are formed in the flow field with a long twisted band, and the velocities are maximum at the center of the vortices. Along the direction of the pipeline, the two vortices move toward the pipe wall from near the twisted band, which can effectively carry the hydrate particles deposited on the wall. With the same Reynolds number, the twisted rate was greater, the spiral strength was weaker, the tangential velocity was smaller, and the pressure drop was smaller. Therefore, the pressure loss can be reduced as much as possible with effect of the spiral flow. In a straight light flow, the Nusselt number is in a parabolic shape with the opening downwards. At the center of the pipe, the Nusselt number gradually decreased toward the pipe wall at the maximum, and at the near wall, the attenuation gradient of the Nu number was large. For spiral flow, the curve presented by the Nusselt number was a trough at the center of the pipe and a peak at 1/2 of the pipe diameter. With the reduction of twist rate, the Nusselt number becomes larger. Therefore, the spiral flow can make the temperature distribution more even and prevent the large temperature difference, resulting in the mass formation of hydrate particles in the pipeline wall. Spiral flow has a good carrying effect. Under the same condition, the spiral flow carried hydrate particles at a distance about 3–4 times farther than that of the straight flow.

Simulation Study for Heat Transfer Performance of Spiral Flow Double-Pipe Heat Exchanger

2012 ◽  
Vol 550-553 ◽  
pp. 3024-3028
Author(s):  
Yi Ning Wang ◽  
Qun Hui Lu ◽  
Yang Yan Zheng ◽  
Biao Yuan
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Shear Force ◽  
Heat Transfer Performance ◽  
Engineering Application ◽  
Transfer Performance ◽  
Spiral Flow ◽  
Surface Shear ◽  
Double Pipe ◽  
Pipe Heat

In this article, simulation analysis has been performed for the flow and heat transfer performance of spiral flow double-pipe heat exchanger using finite volume method, respectively for the relationship between Nu and the average shear force on inner pipe outer wall at different turbulent flow Re with different radial offset of inlet and outlet pipes and different spacing of inlet and outlet pipes. The results show that, as compared with an ordinary double-pipe heat exchanger, in a spiral flow double-pipe heat exchanger, both inner pipe convective heat exchange coefficient and inner pipe wall surface shear force are lower, with the magnitude of reduction related to a number of factors such as radial offset of inlet and outlet pipes and Re. The study in this article has provided theoretical basis for further engineering application of spiral flow double-pipe heat exchangers.

Heat transfer and combustion for a spiral flow in an ideal-displacement reactor

1991 ◽  
Vol 60 (2) ◽  
pp. 171-177 ◽  
Author(s):  
I. G. Dik ◽  
O. V. Matvienko
Keyword(s):  
Heat Transfer ◽  
Spiral Flow ◽  
Ideal Displacement ◽  
Displacement Reactor

Effects of blade shape on convective heat transfer induced by a piezoelectrically actuated vibrating fan

2018 ◽  
Vol 132 ◽  
pp. 597-609 ◽  
Author(s):  
Xin-Jun Li ◽  
Jing-zhou Zhang ◽  
Xiao-ming Tan
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Blade Shape
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