Liquid Breakup in Microgravity (Break)

abstract

This project aims to study the effect of microgravity on the break-up of liquids and formation droplets. The project proposes to experimentally study the way liquid filaments thin and breakup in the Bremen Drop Tower. The formation of droplets is a natural process that occurs during dripping, jetting or spraying of a liquid. Drops are formed by the action of surface tension that thins and eventually breaks a jet or a liquid filament into one or more droplets. The thinning behaviour is ruled by the liquid properties and the dynamics of the system. Most previous works, including very modern studies, have been centred on simple liquids and very few have used complex fluids such as those containing particles (colloids), and none have studied liquid filaments under conditions of microgravity. This proposal focuses on quantifying the effect of gravity on the rate of thinning of colloidal liquids prior break-up. The project is centred on the development of a stand- alone experiment to visualise by high-speed imaging the creation, necking and break-off process of liquid filaments. High speed images will be analysed by a Matlab code to extract the filament properties such as the thinning behaviour in terms of time until breakup. We propose to run the setup in the ESA Drop tower facility as to study the breakup behaviour at zero gravitational pulls. We plan to compare this behaviour with the one observed at conventional gravitational conditions by carrying out experiments in our laboratories in the University of London. Results will also be contrasted with established theories and models that claimed to predict the thinning behaviour of liquids. The experimental setup, now under design and construction, consists of a filament stretching rig that will be operated by a servo motor under digital and remote control.

• Liquid Breakup in Microgravity (Break), Drop Your Thesis! 2016 - Final Report. ESA Human Spaceflight and Exploration, Erasmus Experiment Archive

experiment year: 2016
number of drops: 5