Bubble growth model and its influencing factors in a polymer melt under nonisothermal conditions

2018 ◽  
Vol 136 (12) ◽  
pp. 47210 ◽  
Author(s):  
Yun Zhang ◽  
Chunling Xin ◽  
Xiaohu Li ◽  
Mughal Waqas ◽  
Yadong He
e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Uday S. Agarwal

AbstractExisting approaches to simulate the bubble growth/collapse in viscoelastic liquids use the integral form of a constitutive equation, that can additionally be analytically integrated over the radial domain. Here we represent the process by a system of simultaneous partial differential equations, with fixed and finite boundaries. This enables a direct computer implementation with commercially available software, with little additional programming effort. The involved co-ordinate transformation preferably does not correspond to the material co-ordinates. The surrounding liquid can be simulated as being a finite film or of infinite extent, with simply a change in one computational parameter. We simulate hydrodynamically induced bubble dynamics in viscolelastic liquids, and estimate the flow strength (elongational strain rate) and its possible role in flow induced scission of polymer chains in liquids experiencing bubble collapse. Calculations are also performed to evaluate the influence of backbone and branch lengths when the surrounding fluid is a branched polymer melt, using the pom-pom model to describe the rheological behavior.


Author(s):  
Chang Cai ◽  
Hong Liu ◽  
Xi Xi ◽  
Ming Jia ◽  
Hongchao Yin

2018 ◽  
Vol 49 (12) ◽  
pp. 1199-1218
Author(s):  
Dewen Yuan ◽  
Xiao Yan ◽  
Deqi Chen ◽  
Yunke Zhong ◽  
Yanping Huang ◽  
...  

Author(s):  
Martin Gschosser ◽  
Andreas H. Mehrle ◽  
Achraf Kallel ◽  
Abbas Tcharkhtchi

2012 ◽  
Vol 614-615 ◽  
pp. 385-390
Author(s):  
Ti En Zhang ◽  
Wei Zheng Zhang ◽  
Yuan Fu Cao

Based on the equation that the heat conduction from the bubble underlying layer is balanced with the heat convection of bubble cooling and the latent heat of evaporation, with the help of zhao model a new bubble growth model for the forced convective subcooled boiling in the engine cooling system is developed with the consideration of the thermal boundary layer impact on the bubble growth. And an experiment is designed to verify the theoretical model. Then the Klausner model for predicting the bubble lift-off diameters is amended with the built bubble growth model. In addition, the bubble lift-off diameters at the different velocity are predicted, which is verified with the experimental data.


Author(s):  
Pruthvik A. Raghupathi ◽  
Satish G. Kandlikar

Recent literature claims that boiling performance can be significantly improved by using evaporation momentum force to control the trajectory of a bubble. This approach merits a detailed investigation into evaporation momentum force and its effect on bubble growth and bubble trajectory. In this paper an expression for evaporation momentum pressure experienced by a bubble is determined. This is incorporated into a well established bubble growth model (Mikic-Rohsenow) to evaluate the effect of evaporation momentum pressure on bubble growth rate. The effect of evaporation momentum force on a bubble growing in asymmetric temperature field is then studied and the resultant trajectory is evaluated. The results are compared with experimental data of bubble trajectory subjected to an asymmetric temperature condition. The final results suggest that the evaporation momentum pressure in the vicinity of contact line can significantly change the bubble trajectory, and surfaces designed to exploit this effect seem to be promising for boiling enhancement.


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