Beschreibung:
<jats:title>Abstract</jats:title><jats:p>This paper reports on the hydrodynamic droplet instabilities of different sizes and viscosities due to shear forces in a rectangular channel. Water‐glycerine droplets of different volumes are investigated. A new and nonambiguous definition for the critical velocity of droplet detachment and a new mathematical correlation between the critical velocity <jats:italic>v</jats:italic><jats:sub>crit</jats:sub> and the fluid properties are presented. The measurements show that <jats:italic>v</jats:italic><jats:sub>crit</jats:sub> decreases with the droplet volume but at the same time the contour deformation increases. With increasing viscosity of the liquid droplet, i.e., higher glycerine mass fraction, the contour deformation becomes more prominent and an increase in <jats:italic>v</jats:italic><jats:sub>crit</jats:sub> can be observed. With respect to the fluid properties and droplet volumes, three different motion patterns are detected.</jats:p>