Abstract Heating of a droplet on a stretchable hydrophilic surface is investigated and fluid dynamics in the droplet under the heating load is assessed. Elastomer wafers are considered as the sample material and the fixture is designed and manufactured to assure uniform stretching of the droplet located elastomer surface. Droplet adhesion and possible slipping/sliding of the droplet are evaluated during stretching of the sample surface. Numerical simulations are carried out to predict thermal and flow response of the droplet fluid before and after stretching. The effect of droplet volume on heating enhancement is also included in the numerical simulations. Experiments are carried out using a high-speed recording system towards comparing the flow predictions. Findings reveal that predictions are in agreement with their counterparts of experiments. Stretching of sample surface increases wetting area and lowers height of the droplet while influencing thermal flow structures in the fluid. The Nusselt and the Bond numbers increase with enlarging stretching, which becomes more visible for large droplet volume (80 µl). Hence, stretching corresponding to 80% extension of elastomer surface gives rise to 60% improvement in the Nusselt number.

中文翻译：

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可拉伸亲水表面液滴的加热分析

摘要 研究了可拉伸亲水表面上液滴的加热，并评估了加热负荷下液滴中的流体动力学。弹性体晶片被视为样品材料，并且夹具的设计和制造确保了位于弹性体表面的液滴的均匀拉伸。在拉伸样品表面期间评估液滴粘附和液滴可能的滑动/滑动。进行数值模拟以预测拉伸前后液滴流体的热和流动响应。液滴体积对加热增强的影响也包括在数值模拟中。使用高速记录系统进行实验以比较流量预测。研究结果表明，预测与他们的实验对应物一致。样品表面的拉伸会增加润湿面积并降低液滴的高度，同时影响流体中的热流结构。Nusselt 和 Bond 数随着拉伸的扩大而增加，对于大液滴体积 (80 µl) 变得更加明显。因此，对应于弹性体表面 80% 延伸的拉伸导致努塞尔数提高 60%。