Flow and Heat Transfer Characteristics of Melt Droplet with Non-uniform Heating Temperature

Abstract

According to the spreading dynamics of a single melt droplet on the heated substrate, the mathematical model of the melt droplet contacting hot dry wall is established, and the transport process of the melt droplet is numerically simulated by the VOF method. The effects of the wall temperature profile on the spreading behavior and the heat transfer characteristics of the melt droplet are elaborated. With the increase of the wall temperature difference, the Marangoni convection is strengthened, the spreading diameter and the spreading height of the melt droplet become large and the spreading rate slows down periodically. The wall heat flux also increases and decays periodically. The droplet temperature increases periodically in the early stage of spreading, and increases linearly in the later stage. The melt droplet moves right under the Marangoni force, which results in an obvious difference in the velocity field and the phase interface between the right half and the left half of the melt droplet. The melt droplet temperature distribution shows layered and radial for uniform and linear wall temperature, respectively. This would help to reveal the spreading behavior and the heat transfer mechanism between the melt droplet and the horizontal hot dry wall, make up for the lack of experiment, and provide theoretical guidance for enhancing iron and steel smelting.