Prediction of Melt Flow Effects on Dendrite Growth

The effects of melt flow on dendrite growth during solidification are studied by the quantitative phase field model coupling the Navier-Stokes equations. Through analyzing the relationship between flow velocity and dendrite growth rate in simulations, a flow Peclet number involving with characteristic flow velocity, characteristic length of the zone affected by flow and thermal (solute) diffusion coefficient, is suggested for dendrite growth under convections. The growth rate increment due to flow follows a power-law relationship with the Peclet number. As the Peclet number is much higher than one, the influence of convection on dendrite growth is apparent, whereas as it is below one, the flow effects can be neglected.