When a test tube partially filled with liquid is dropped onto a solid surface, it generates a liquid jet with a narrow, focused tip, known as Pokrovski's experiment. The jet formation mechanism arises from the velocity field induced by the impact and the flow-focusing effect at the concave gas-liquid interface. This video demonstrates the motion of the gas-liquid interface under variations in container shape, liquid height, and liquid composition. This simple mechanism enables the rapid ejection of high-viscosity liquids and powders, highlighting its potential as a novel technology for ejection and coating applications.
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