Experimental Investigation of the Mechanisms of Spontaneous Bending of a Viscous Jet

The mechanisms of the bending flow of a viscous jet (Ohnesorge number greater than 0.05) flowing out of a capillary channel at a low velocity (Weber number is about unity) are experimentally investigated. The bending is due to the effect of internal forces and is not related with the interaction between the liquid and the atmosphere, which is confirmed by experiments performed in a vacuum chamber. A region of intense jet bending amounting to fifteen degrees is formed near the channel end section, at a distance of the jet diameter. Further downstream the jet is “straightened,” the angle of bending being reduced. The dependences of the greatest and overall bending angles on the jet velocity are obtained for different Ohnesorge numbers. The velocities, at which the deflection is maximum, are revealed. The deviation angle values corresponding to large velocities are determined.