Liquid drop impact on dry, solid surfaces has been studied to elucidate the role of control parameters, such as drop size, impact velocity, liquid properties, surface roughness, and wettability, on the mechanism of splashing phenomenon. It has been shown more recently that ambient gas plays a pivotal role in initiating the disintegration mechanisms leading to the ejection of secondary droplets from an impacting drop. Through systematic experiments, the role of target surface temperature in altering the morphology of a splash outcome of impacting fuel drops is investigated in the present work. It is observed that at elevated surface temperatures, the heated air film present very close to the hot surface suppresses splashing and consequently raises the splash threshold Weber number of the impacting fuel drop. For a given Weber number, the morphology of the impacting drop shifts from splashing to spreading with a rise in the surface temperature through an intermediate transition regime, characterized by the tendency of the liquid sheet to recontact the drop lamella without ejecting any secondary droplets. The experimental observations are compared with theoretical model predictions reported in the literature, and fair agreement is found in terms of both the observed splash suppression and the underlying mechanisms that govern the identified morphological regimes.

中文翻译：

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燃料滴溅到加热的固体表面上

已经研究了液滴对干燥固体表面的影响，以阐明控制参数（例如液滴尺寸、冲击速度、液体性质、表面粗糙度和润湿性）对飞溅现象机制的作用。最近的研究表明，环境气体在启动分解机制中起着关键作用，从而导致从撞击液滴中喷射出二次液滴。通过系统实验，在目前的工作中研究了目标表面温度在改变撞击燃料滴的飞溅结果形态方面的作用。据观察，在升高的表面温度下，非常靠近热表面的热空气膜抑制了飞溅，从而提高了撞击燃料滴的飞溅阈值韦伯数。对于给定的韦伯数，撞击液滴的形态随着表面温度的升高从飞溅转变为通过中间过渡状态的扩散，其特征在于液体层倾向于重新接触液滴薄片而不喷射任何二次液滴。将实验观察结果与文献中报道的理论模型预测进行比较，在观察到的飞溅抑制和控制已识别形态机制的潜在机制方面都发现了相当的一致性。