Analysis of thermophysical characteristic of SiO2/water nanofluid and heat transfer enhancement with field synergy principle

2018 ◽  
Vol 10 (6) ◽  
pp. 063704 ◽  
Author(s):  
Suying Yan ◽  
Huiying Zhang ◽  
Feng Wang ◽  
Rui Ma ◽  
Yuting Wu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermophysical Characteristic ◽  
Field Synergy ◽  
Transfer Enhancement ◽  
Field Synergy Principle

The effects of longitudinal fins on thermal performance of a curved microchannel: A numerical study

2014 ◽  
Vol 229 (5) ◽  
pp. 906-915 ◽  
Author(s):  
Hosseinali Soltanipour ◽  
Nader Pourmahmoud ◽  
Iraj Mirzaee
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Curvature Radius ◽  
Field Synergy ◽  
Transfer Enhancement ◽  
Field Synergy Principle ◽  
Second Law Analysis

In this paper, flow structure, heat transfer, and entropy generation in an internally finned curved microchannel are studied. Three dimensional numerical simulations are performed using a finite volume approach. The effect of fin height, mass flow rate, and curvature radius on heat transfer enhancement and pressure losses are explored. The field synergy principle is employed to explain the heat transfer enhancement mechanism. The second law analysis is also performed to indicate the influence of fins on the entropy generation in the curved microchannel. It is found that regardless of mass flow rate, the fin height of a* = 0.35 provides the maximum heat transfer enhancement. Numerical results reveal that the ratio of heat transfer coefficient (and pressure drop) of finned microchannel to unfinned microchannel depends on the curvature radius and mass flow rate. The field synergy principle and the second law analysis confirm that for the fin height of a* = 0.35, the microchannel has the optimal thermal performance.

scholarly journals Heat transfer enhancement and field synergy analysis of vacuum collector tube with inserted rotor

AIP Advances ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 045224
Author(s):  
Zhi Geng ◽  
Jifeng Gao ◽  
Haochen Liu ◽  
Ziyuan Mo ◽  
Yujiong Gu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Field Synergy ◽  
Transfer Enhancement

Flow and Heat Transfer in Microchannels With Dimples and Protrusions

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
Jibing Lan ◽  
Yonghui Xie ◽  
Di Zhang
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Flow Characteristics ◽  
Field Synergy ◽  
Transfer Enhancement ◽  
Rectangular Microchannel ◽  
Field Synergy Principle ◽  
Flow And Heat Transfer ◽  
Better Than

Flow characteristics and heat transfer performances in a rectangular microchannel with dimples/protrusions are studied numerically in this research. The height and the width of the microchannel is 200 μm and 50 μm, respectively. The dimple/protrusion diameter is 100 μm, and the depth is 20 μm. The effects of Reynolds number, streamwise pitch, and arrangement pattern are examined. The numerical simulations are conducted using water as the coolant with the Reynolds number ranging from 100 to 900. The results show that dimple/protrusion technique in mcirochannel has the potential to provide heat transfer enhancement with low pressure penalty. The normalized Nusselt number is within the range from 1.12 to 4.77, and the corresponding normalized friction factor is within the range from 0.94 to 2.03. The thermal performance values show that the dimple + protrusion cases perform better than the dimple + smooth cases. The flow characteristics of the dimples/protrusions in microchannel are similar to those in conventional channel. Furthermore, from the viewpoint of energy saving, dimples/protrusions in microchannel behave better than those in conventional channel. Also from the viewpoint of field synergy principle, the synergy of the dimple + protrusion cases are much better than the dimple + smooth cases. Moreover, the synergy becomes worse with the increase in the Reynolds number and decrease in the streamwise pitch.

Numerical Study on Heat Transfer Enhancement Performence of the Helical Blade Rotors

2013 ◽  
Vol 561 ◽  
pp. 101-106
Author(s):  
Zhen Zhang ◽  
Hua Yan ◽  
Yu Mei Ding ◽  
Chang Feng Guan ◽  
Wei Min Yang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermal Performance ◽  
Friction Loss ◽  
Field Synergy ◽  
Transfer Enhancement ◽  
Numerical Studies ◽  
Performance Factor ◽  
Thermal Performance Factor ◽  
Plain Tube

Based on the advantages of polymer materials over other materials, rotors which are made of the polymer material, are the functional elements of the rotor-assembled strand, and rotate under certain mass flow rate to obtain heat transfer enhancement and online automatic cleaning. The paper carried out numerical studies on heat transfer and friction loss characteristics of the tube fitted with rotors of different spaces. The comparison of the field synergy angle between plain tube and the tube fitted with rotors was also presented in the paper. The numerical data had good agreement with the experimental data. The numerical studies indicated that the field synergy angle of the rotors inserted tube were significantly smaller than that of the plain tube, which validated that the rotors could significantly enhance heat transfer process and had a better comprehensive performance of heat transfer enhancement though extra friction loss was generated. In addition, both the Nusselt number and friction factor of the tube fitted with rotors increased with the increasing space between rotors; the thermal performance factor of the rotors were all higher than 1, which validated the heat transfer enhancement function of the rotors; meanwhile, the thermal performance factor increased with the space between rotors.

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