The formation and evolution of micron-sized droplets of a Newtonian liquid generated on demand in an industrial inkjet printhead were studied experimentally and simulated numerically. The shapes and positions of droplets during droplet formation were observed using a high-speed camera and compared with their numerically obtained analogues. Both the experiments and the simulations use practical length scales for inkjet printing. The results show how fluid properties, specifically viscosity and surface tension, affect the drop formation, ligament length and break-off time. We identify the parameter space of fluid properties for producing single drops at a prescribed speed and show this is not simply a restriction on the Ohnesorge number, but that there is an additional restriction on the Reynolds number that is distinct from the Reynolds number limit associated with the prevention of splashing. This phase diagram provides more precise guidance on the space of fluid parameters for jetting single droplets in drop-on-demand inkjet printers.

中文翻译：

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按需滴印中的喷射行为：实验室实验和数值模拟

对工业喷墨打印头中按需产生的牛顿液体的微米级液滴的形成和演化进行了实验研究，并进行了数值模拟。使用高速照相机观察液滴形成过程中的液滴的形状和位置，并将其与从数值上获得的类似物进行比较。实验和模拟都使用实际的长度刻度进行喷墨打印。结果表明，流体性能，特别是粘度和表面张力，如何影响液滴的形成，韧带长度和断裂时间。我们确定了用于以规定速度产生单滴液体的流体特性的参数空间，并表明这不仅仅是对Ohnesorge数的限制，但雷诺数有一个额外的限制，这与防止飞溅相关的雷诺数限制不同。此相图提供了有关在按需喷墨打印机中喷射单个液滴的流体参数空间的更精确指导。