Boiling and Evaporation of Falling Film on Horizontal Tubes and its Enhancement on Grooved Tubes

1999 ◽  
pp. 325-346 ◽  
Author(s):  
Yasunobu Fujita
Keyword(s):  
Falling Film ◽  
Horizontal Tubes ◽  
Boiling And Evaporation

Effects of Liquid Supply Method on Falling-Film Mode Transitions on Horizontal Tubes

2013 ◽  
Vol 34 (7) ◽  
pp. 562-579 ◽  
Author(s):  
Xiaofei Wang ◽  
Maogang He ◽  
Kai Lv ◽  
Hualiang Fan ◽  
Anthony M. Jacobi
Keyword(s):  
Falling Film ◽  
Horizontal Tubes ◽  
Mode Transitions

Wettability Effects on Falling Film Flow and Heat Transfer Over Horizontal Tubes in Jet Flow Mode

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Avijit Karmakar ◽  
Sumanta Acharya
Keyword(s):  
Heat Transfer ◽  
Contact Angle ◽  
Nusselt Number ◽  
Film Flow ◽  
Jet Flow ◽  
Equilibrium Contact Angle ◽  
Flow Mode ◽  
Falling Film ◽  
Tube Surface ◽  
Horizontal Tubes

Abstract The performance of a falling-film heat exchanger is strongly linked to the surface characteristics and the heat transfer processes that take place over the tubes. The primary aim of this numerical study is to characterize the influence of surface wettability on the film flow behavior and its associated surface heat transfer in the jet-flow mode. Volume of fluid (VOF) based simulations are carried out for horizontal tubes with different surface wettabilities. The wettability of the tube surfaces is represented using the Kistler's dynamic contact angle model. Surface wettability effects ranging from superhydrophilic to superhydrophobic are studied by varying the equilibrium contact angle from 2 deg to 175 deg. Two different liquid mass flow rates of 0.06 and 0.18 kg/m-s corresponding to the inline and staggered jet flow modes are studied. Results are presented in terms of the liquid film thickness, the contact areas between the different phases (solid–liquid and liquid–air), and the heat transfer coefficient or Nusselt number. The resistance imposed by the increasing contact angles inhibits the extent of the liquid spreading over the tube surface, and this, in turn, influences the liquid film thickness, and the wetted area of the tube surface. A significant decrement in the heat transfer rate from the tube surfaces was observed as the equilibrium contact angle increased from 2 deg to 175 deg. The local distributions of the Nusselt number over the tube surface are strongly influenced by the flow recirculation in the liquid bulk.

Experimental study of falling-film mode transitions between horizontal tubes in CaCl2/water absorber

2014 ◽  
Vol 23 (4) ◽  
pp. 338-345 ◽  
Author(s):  
Zhen Xu ◽  
Wenqian Sun ◽  
Yuan Lu ◽  
Yunhan Xiao ◽  
Yingchun Xie
Keyword(s):  
Experimental Study ◽  
Falling Film ◽  
Horizontal Tubes ◽  
Mode Transitions

scholarly journals Flow Pattern Transitions in and Hysteresis Effects of Falling Film Flow over Horizontal Tubes Related to LNG Heat Exchangers

2015 ◽  
Vol 64 ◽  
pp. 23-32 ◽  
Author(s):  
Anders Austegard ◽  
Mayukh Bandopadhyay ◽  
Sigurd Weidemann Løvseth ◽  
Amy Brunsvold
Keyword(s):  
Flow Pattern ◽  
Heat Exchangers ◽  
Film Flow ◽  
Falling Film ◽  
Horizontal Tubes
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