Lapping flow and starting plume on an evenly heated horizontal plate

Abstract Transient laminar flows on an evenly heated horizontal plate are a common phenomenon in nature and industry. In this study, a lapping flow and a starting plume on a horizontal plate suddenly heated with a uniform heat flux are investigated using a scaling analysis, and the dynamics and heat transfer are analyzed. It is demonstrated that the starting plume has three possible scenarios and four regimes, including an unsteady viscous conduction regime, an unsteady inertial conduction regime, a steady inertial conduction regime and a steady viscous conduction regime. In addition, the obtained scaling laws are validated by numerical results calculated for Rayleigh numbers of 2 × 10 3  ≤ Ra ≤ 6 × 10 5 .