Motion of an Elastic Drop through an Orifice in a Thin Plate

Impingement of drops of water and polymer solutions on a thin plate with a solitary round orifice is studied. The drop diameter before the impingement di coincides with that of the orifice dt and is equal to 3 mm. The drops fell from heights of 5, 10, and 20 mm, their velocities before the impingement amounting to 0.31, 0.44, and 0.63 m/s. The drops flew through the orifice touching slightly its edges. High-speed photography was used to fix different stages of the collision between a drop and the obstacle. It is found that a considerable deceleration of the jet by the orifice can be observable for the impingement parameters considered, down to the complete stopping of the drop flight. The mechanisms of the observable phenomena and the effect of different factors are discussed.