A Study of liquid rope coiling

Abstract

A helical coiling is formed when thin stream of viscous silicone oil falling from an outlet of the tank on a solid stationary surface or collecting plate. In the results varying coiling frequency is observed with diameter of outlet valve and height of coiling is changes. In this phenomenon viscosity play the important role with silicone oil because it is behave like Newtonian fluid and in this fluid magnitude of elasticity is not significant as compare to viscosity. Experiment is performed to understand the coiling behaviour of viscous liquid. Here silicone oil is use as a working fluid with density of 920 kg m3 and dynamic viscosity is 0.15 Pa.S at room temperature, for capturing the images used high speed camera of resolution of 786*786 pixels, It can capture 1000 frame per second. For storing silicone oil, acrylic tank of 250mm*250mm*250mm is used, in which oil is filled up to 100mm height. In the result it is observed that for small diameter of outlet of tank mostly coil is appeared and when diameter was increased then coiling behaviour convert into folding phenomenon.