Effect of viscoelasticity on stability of liquid curtain.

The effect of viscoelastic forces on the hole growth speed in a liquid curtain and on the critical flow rate below which a liquid curtain breaks was studied by high-speed visualization. Different Boger-like aqueous solutions were used as the viscoelastic liquids. The expansion of a hole initiated within the liquid curtain leads to the curtain breakup. The results show a strong stabilizing effect of the viscoelastic forces; the minimum flow rate for stable curtain falls drastically by adding small amounts of high molecular weight polymer. The results reveal that the mechanisms for the increased stability are that the initiation of the hole is delayed and the speed at which it expands is also reduced, as the viscoelastic forces become stronger. [ABSTRACT FROM AUTHOR]