Fluid flow and heat transfer on a falling liquid film with surfactant from a heated vertical surface

2007 ◽  
Vol 21 (11) ◽  
pp. 1807-1812 ◽  
Author(s):  
B. H. Kang ◽  
K. H. Kim ◽  
D-Y Lee
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Liquid Film ◽  
Vertical Surface ◽  
Flow And Heat Transfer ◽  
Falling Liquid Film

Study on the Flow and Heat Transfer Characteristics of Micro-Scale Droplets and Fluid on Dynamic Liquid Film Condition by Lattice Boltzmann Method

2019 ◽  
Author(s):  
Yichao He ◽  
Yan Li ◽  
Zhuang Ding ◽  
Han Yuan ◽  
Ning Mei
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Liquid Film ◽  
Flow Rate ◽  
Microfluidic Chip ◽  
Lattice Boltzmann ◽  
Wall Surface ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Boltzmann Method

Abstract The lab on a chip is of great value in the analytical chemistry, biology and pharmacy. So that it is very important to study the formation and control of droplet in chips. The fluid flowing under the condition of dynamic liquid film is researched innovatively in this paper. Its inspiration is derived from bionics (fish skin, etc.), which has a broad application prospect in reducing the resistance in water and weakening the heat transfer. Dynamic liquid film refers to the dynamic thin liquid layer with the hydrophilic property on the surface of wall under the pressure of outside fluid flow. The insolubility between liquid film and fluid creates a relatively stable flowing environment. In this paper, the formation and influencing factors of the droplet in the microfluidic chip are studied by the Lattice Boltzmann method (LBM), and the flow and heat transfer characteristics of fluid in microchannel is studied with microfluidic chip as the carrier under the condition of insoluble dynamic liquid film existing on the wall surface. LBM has certain advantages in boundary processing, parallel operation and tracing phase interface automatically. Using SC model of LBM (for two component flow), the process of formation and movement of the droplet in microfluidic chip are simulated numerically after verified by Laplace‘s law. The result shows that the hydrophobic characteristics between the discrete phase and the wall surface and increased flow rate of the continuous phase will decrease the droplets’ volume and increase the producing frequency. In addition, the fluid flow in the microchannel is simulated under the condition of insoluble dynamic liquid film on the wall surface. The simulation result shows that when the fluid flow rate increases, the friction loss decreases and the heat transfer capacity decreases with the existence of the liquid film. The lower the dissolution trend between fluid and liquid film is, the greater the variation trend of fluid parameters will be. By comparing the results of experiment and simulation, the consistent results are obtained.

Cooling of a Very Hot Vertical Surface by a Falling Liquid Film

1974 ◽  
Vol 96 (2) ◽  
pp. 126-131 ◽  
Author(s):  
K. H. Sun ◽  
G. E. Dix ◽  
C. L. Tien
Keyword(s):  
Heat Transfer ◽  
Liquid Film ◽  
Vertical Surface ◽  
Temperature Profiles ◽  
Continuous Film ◽  
Falling Liquid Film ◽  
Biot Numbers ◽  
Transfer Mechanisms ◽  
Two Temperature ◽  
Good Agreement

The present study analyzes the cooling of a very hot vertical surface by a falling liquid film. An analytical model is developed to characterize this phenomenon in three distinctive regions: a dry region ahead of the wet front, a sputtering region immediately behind the wet front, and a continuous film region further upstream. The analysis leads to predictions of the wet front velocity, the sputtering length, and the temperature profiles with respect to the wet front. The heat transfer mechanisms are shown to be dependent upon two temperature parameters characterizing the initial wall temperature and the temperature range for sputtering, and two Biot numbers comparing the convective heat transfer in the liquid film region and the sputtering region with longitudinal heat conduction. The predictions are in good agreement with existing experimental results.

A Parametric Numerical Study of Fluid Flow and Heat Transfer in a Computer Chassis

2015 ◽  
Vol 9 (3) ◽  
pp. 242 ◽  
Author(s):  
Efstathios Kaloudis ◽  
Dimitris Siachos ◽  
Konstantinos Stefanos Nikas
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Flow And Heat Transfer
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