Transition in high Prandtl number buoyant-thermocapillary convection

2008 ◽  
Author(s):  
Bin Zhou ◽  
Li Duan ◽  
Liang Hu ◽  
Qi Kang
Keyword(s):  
Prandtl Number ◽  
Thermocapillary Convection ◽  
High Prandtl Number

scholarly journals Effects of external environment on thermocapillary convection of high prandtl number fluid

2016 ◽  
Vol 40 ◽  
pp. 06003
Author(s):  
Ruquan Liang ◽  
Fuqiang Yan ◽  
Xiaoyuan Li ◽  
Shuo Zhang ◽  
Shuo Yang
Keyword(s):  
Prandtl Number ◽  
Thermocapillary Convection ◽  
External Environment ◽  
High Prandtl Number

Transient Thermocapillary Convection in a Molten or Weld Pool

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
P. S. Wei ◽  
C. L. Lin ◽  
H. J. Liu ◽  
C. N. Ting
Keyword(s):  
Prandtl Number ◽  
Molten Pool ◽  
Thermocapillary Convection ◽  
Welding Process ◽  
Melting Process ◽  
Scanning Speed ◽  
Surface Velocity ◽  
Vortex Cell ◽  
Incident Flux ◽  
High Prandtl Number

This study presents a numerical scenario for the effect of thermocapillary convection on the transient, two-dimensional molten pool shape during welding or melting. Tracing the melting process is necessary to achieve a better and more complete understanding of the physical mechanism of welding. This model is used to simulate a steady state, three-dimensional welding process, by introducing an incident flux with a Gaussian distribution with a time-dependent radius determined by scanning speed and distribution parameter. Aside from presenting the variations of peak surface velocities and temperature, and depth and width of the molten pool with time, the predicted results of this work show that surface velocity and temperature profiles for a high Prandtl number strongly deform in the course of melting. The velocity profile eventually exhibits two peaks, located near the edges of the incident flux and the pool, respectively. Conversely, only one peak velocity occurs near the pool edge for a small Prandtl number. In all cases, surface temperature can ultimately be divided into hot, intermediate, and cold regions. The pool becomes deep due to an induced secondary vortex cell near the bottom of the pool for a small Prandtl number. For a high Prandtl number, the pool edge is thin and shallow, as a result of penetration into the solid near the top surface. The predicted results agree with those obtained using a commercial computer code.

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