کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
159303 | 457032 | 2005 | 9 صفحه PDF | دانلود رایگان |
The onset of buoyancy-driven convection in an initially isothermal, quiescent fluid layer heated from below with a constant heating rate is analyzed by the propagation theory. Here the dimensionless critical time τcτc to mark the onset of convective motion is presented as a function of the Rayleigh number RaφRaφ and the Prandtl number Pr . The present stability analysis predicts that for a given large RaφRaφ, τcτc decreases with increasing Pr and it is independent of the conditions of the upper boundary. For deep-pool systems, the deviation of the temperature profile from conduction state occurs starting from a certain time τo≅4τcτo≅4τc. The present predictions are compared with other models and existing experimental results in the whole time domain.
Journal: Chemical Engineering Science - Volume 60, Issue 19, September 2005, Pages 5363–5371