Scaling laws of buoyant flows on a suddenly heated horizontal plate

Buoyant flows on a heated horizontal plate often occur in nature and industry. A starting plume and a lapping flow on a suddenly heated horizontal plate are investigated in this study. The corresponding dynamics and heat transfer are discussed through scaling analysis and direct numerical simulation. The scaling analysis demonstrates that there are two scenarios for buoyant flows on the plate for different Rayleigh numbers; that is, a starting plume can rise under the unsteady viscosity conduction regime or the steady viscosity conduction regime for Ra > 1. In addition, the scaling laws obtained are also verified by the corresponding numerical results.