Paper Number
FE6
Session
Foams, Emulsions, Surfactants, and Micelles
Title
Mixing dynamics of bilgewater emulsions in Taylor Couette flows
Presentation Date and Time
October 11, 2021 (Monday) 1:30
Track / Room
Track 3 / Meeting Room A-B
Authors
- Panwar, Vishal (University of Minnesota, Twin Cities, Mechanical Engineering)
- Dutcher, Cari (University of Minnesota, Mechanical Engineering)
Author and Affiliation Lines
Vishal Panwar and Cari Dutcher
Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455
Speaker / Presenter
Panwar, Vishal
Keywords
experimental methods; emulsions
Text of Abstract
Taylor-Couette flows between two concentric, rotating cylinders, is ideal for studying the mixing dynamics and stability of emulsions due to the availability of wide variation of hydrodynamic flow states. The requirement to control the concentration of oil discharge at sea from the marine vessels require a better understanding of the stability and formation of Navy standard bilge mix emulsions (50% marine diesel fuel, 25% steam lube oil, 25% Diesel lube oil) onboard these ships. In this study, a pre-prepared (IKA: T-25 digital Ultra-Turrax) concentrated oil-water emulsion is directly injected into the annulus of the Taylor-Couette cell containing surfactant-water solution at varied flow conditions to determine the intermixing rate or dispersion rate of the emulsion. The optical properties of the Tayler-couette cell enables us to visually study the mixing and spread of the emulsion in the solution. It was observed that the dispersion coefficient showed an approximately linear response to increasing inner cylinder speed of Taylor-couette cell. Samples were collected at different mixing stages from the TC cell and laser diffraction particle analyzer was used to characterize droplet size distribution for the mixing stages. The measurements indicate an initial droplet breakup followed by shear induced coalescence to form a larger median droplet size with time at lower mixing speed. Whereas as the mixing speed increases, the droplets continues to break under increased shear rate and a delay in droplet coalescence was observed.