蒸汽的滴状冷凝进程中，液滴生长包括冷凝生长与合并生长。液滴生长作为影响滴状冷凝演变的关键行为，其研究有助于深入理解滴状冷凝演变机制和换热机理。本文基于滴状冷凝全过程的数值模拟，针对不同凝结核密度下的滴状冷凝演变和液滴生长方式开展研究。模拟中采用Cassie 模型对液滴的冷凝生长进行描述，耦合邻近搜索算法和守恒定律对液滴的合并生长过程进行模拟。经实验结果和理论模型验证，本文模拟方法具有较高的可靠性。结果表明：最大液滴尺寸主要来源于合并生长，其增速是衡量滴状冷凝演变速度的表征；随着凝结核密度的升高，演变速度呈线性提高，换热能力先增后减；高合并频率的表面能有效提高合并生长对最大液滴尺寸的贡献比例。

During the dropwise condensation process of steam, droplet growth includes condensation growth and coalescence growth. Droplet growth is a key behavior affecting the evolution of dropwise condensation, and its research helps to understand the evolution mechanism and heat transfer mechanism of dropwise condensation. In this paper, based on the numerical simulation of the whole process of dropwise condensation, the dropwise condensation evolution and droplet growth mode under different condensation nucleus densities are studied. In the simulation, the Cassie model was used to describe the condensation growth of droplets, and the combined growth process of droplets was simulated by coupling the proximity search algorithm and the conservation law. The experimental results and theoretical model verify that the simulation method in this paper has high reliability. The results show that the maximum droplet size is mainly derived from the coalescence growth, and its growth rate is a characterization of the evolution rate of dropwise condensation. With the increase of condensation nucleus density, the evolution rate increases linearly, and the heat transfer capacity increases first and then decreases. The surface with a high merging frequency can effectively improve the contribution ratio of coalescence to the maximum droplet size.