Dispensing of rheologically complex fluids at the dripping regime

Hyejin Han, Chongyoup Kim

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Dispensing characteristics of rheologically complex fluids are investigated experimentally at the dripping regime. Two mixtures of ethylene glycol and glycerin (50:50 and 31:69) were used as base Newtonian fluids. As the polymer solution, 1000. ppm of polyacrylamide of 5-6M. g/mol was added to the 50:50 base Newtonian fluid. 2.5, 5 or 7.5. vol% of polystyrene particles of 2. μm in diameter were added to the liquids to prepare particle suspensions. The liquids were dispensed to the air by using a nozzle with the inner and outer diameters of 0.61 and 0.91. mm, respectively. It was found that the drop size is primarily determined by the balance of drop weight and surface tension force holding the drop, and hence drop size does not depend on volume flow rate. The drop diameter is approximately 10% smaller for elastic liquids due to the severe extension of the filament before the detachment from the nozzle. The result also shows that the dripping characteristics of the fluids without the polymer are mainly determined by the balance of the gravity force, surface tension force holding the liquid volume and pressure force. The addition of less than approximately 10% of 2. μm spherical particles hardly changes the dispensing characteristics of Newtonian fluids except at the final stage of detachment. For polymeric liquids, the transient extensional property drastically changes the dripping dynamics. The force balance shows that the strain hardening of the polyacrylamide solution under the extensional flow causes severe retardation of the filament breakup. The filament breakup of the polymeric suspension is further decelerated by the increase in zero shear viscosity as a result of the particle addition.

Original languageEnglish
Pages (from-to)57-67
Number of pages11
JournalJournal of Non-Newtonian Fluid Mechanics
Volume213
DOIs
Publication statusPublished - 2014 Nov 1

Fingerprint

Complex Fluids
Liquid
Newtonian fluids
Newtonian Fluid
Filament
Fluids
fluids
Liquids
liquids
filaments
drop size
Breakup
Nozzle
Polyacrylates
detachment
Surface Tension
nozzles
Surface tension
Nozzles
Suspensions

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Chemical Engineering(all)
  • Materials Science(all)
  • Applied Mathematics

Cite this

Dispensing of rheologically complex fluids at the dripping regime. / Han, Hyejin; Kim, Chongyoup.

In: Journal of Non-Newtonian Fluid Mechanics, Vol. 213, 01.11.2014, p. 57-67.

Research output: Contribution to journalArticle

@article{5e5aab262f0d467a81309c50e6dadf24,
title = "Dispensing of rheologically complex fluids at the dripping regime",
abstract = "Dispensing characteristics of rheologically complex fluids are investigated experimentally at the dripping regime. Two mixtures of ethylene glycol and glycerin (50:50 and 31:69) were used as base Newtonian fluids. As the polymer solution, 1000. ppm of polyacrylamide of 5-6M. g/mol was added to the 50:50 base Newtonian fluid. 2.5, 5 or 7.5. vol{\%} of polystyrene particles of 2. μm in diameter were added to the liquids to prepare particle suspensions. The liquids were dispensed to the air by using a nozzle with the inner and outer diameters of 0.61 and 0.91. mm, respectively. It was found that the drop size is primarily determined by the balance of drop weight and surface tension force holding the drop, and hence drop size does not depend on volume flow rate. The drop diameter is approximately 10{\%} smaller for elastic liquids due to the severe extension of the filament before the detachment from the nozzle. The result also shows that the dripping characteristics of the fluids without the polymer are mainly determined by the balance of the gravity force, surface tension force holding the liquid volume and pressure force. The addition of less than approximately 10{\%} of 2. μm spherical particles hardly changes the dispensing characteristics of Newtonian fluids except at the final stage of detachment. For polymeric liquids, the transient extensional property drastically changes the dripping dynamics. The force balance shows that the strain hardening of the polyacrylamide solution under the extensional flow causes severe retardation of the filament breakup. The filament breakup of the polymeric suspension is further decelerated by the increase in zero shear viscosity as a result of the particle addition.",
keywords = "Dripping mechanism, Drop size, Filament breakup, Strain hardening, Transient elongational viscosity",
author = "Hyejin Han and Chongyoup Kim",
year = "2014",
month = "11",
day = "1",
doi = "10.1016/j.jnnfm.2014.08.019",
language = "English",
volume = "213",
pages = "57--67",
journal = "Journal of Non-Newtonian Fluid Mechanics",
issn = "0377-0257",
publisher = "Elsevier",

}

TY - JOUR

T1 - Dispensing of rheologically complex fluids at the dripping regime

AU - Han, Hyejin

AU - Kim, Chongyoup

PY - 2014/11/1

Y1 - 2014/11/1

N2 - Dispensing characteristics of rheologically complex fluids are investigated experimentally at the dripping regime. Two mixtures of ethylene glycol and glycerin (50:50 and 31:69) were used as base Newtonian fluids. As the polymer solution, 1000. ppm of polyacrylamide of 5-6M. g/mol was added to the 50:50 base Newtonian fluid. 2.5, 5 or 7.5. vol% of polystyrene particles of 2. μm in diameter were added to the liquids to prepare particle suspensions. The liquids were dispensed to the air by using a nozzle with the inner and outer diameters of 0.61 and 0.91. mm, respectively. It was found that the drop size is primarily determined by the balance of drop weight and surface tension force holding the drop, and hence drop size does not depend on volume flow rate. The drop diameter is approximately 10% smaller for elastic liquids due to the severe extension of the filament before the detachment from the nozzle. The result also shows that the dripping characteristics of the fluids without the polymer are mainly determined by the balance of the gravity force, surface tension force holding the liquid volume and pressure force. The addition of less than approximately 10% of 2. μm spherical particles hardly changes the dispensing characteristics of Newtonian fluids except at the final stage of detachment. For polymeric liquids, the transient extensional property drastically changes the dripping dynamics. The force balance shows that the strain hardening of the polyacrylamide solution under the extensional flow causes severe retardation of the filament breakup. The filament breakup of the polymeric suspension is further decelerated by the increase in zero shear viscosity as a result of the particle addition.

AB - Dispensing characteristics of rheologically complex fluids are investigated experimentally at the dripping regime. Two mixtures of ethylene glycol and glycerin (50:50 and 31:69) were used as base Newtonian fluids. As the polymer solution, 1000. ppm of polyacrylamide of 5-6M. g/mol was added to the 50:50 base Newtonian fluid. 2.5, 5 or 7.5. vol% of polystyrene particles of 2. μm in diameter were added to the liquids to prepare particle suspensions. The liquids were dispensed to the air by using a nozzle with the inner and outer diameters of 0.61 and 0.91. mm, respectively. It was found that the drop size is primarily determined by the balance of drop weight and surface tension force holding the drop, and hence drop size does not depend on volume flow rate. The drop diameter is approximately 10% smaller for elastic liquids due to the severe extension of the filament before the detachment from the nozzle. The result also shows that the dripping characteristics of the fluids without the polymer are mainly determined by the balance of the gravity force, surface tension force holding the liquid volume and pressure force. The addition of less than approximately 10% of 2. μm spherical particles hardly changes the dispensing characteristics of Newtonian fluids except at the final stage of detachment. For polymeric liquids, the transient extensional property drastically changes the dripping dynamics. The force balance shows that the strain hardening of the polyacrylamide solution under the extensional flow causes severe retardation of the filament breakup. The filament breakup of the polymeric suspension is further decelerated by the increase in zero shear viscosity as a result of the particle addition.

KW - Dripping mechanism

KW - Drop size

KW - Filament breakup

KW - Strain hardening

KW - Transient elongational viscosity

UR - http://www.scopus.com/inward/record.url?scp=84908207207&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84908207207&partnerID=8YFLogxK

U2 - 10.1016/j.jnnfm.2014.08.019

DO - 10.1016/j.jnnfm.2014.08.019

M3 - Article

AN - SCOPUS:84908207207

VL - 213

SP - 57

EP - 67

JO - Journal of Non-Newtonian Fluid Mechanics

JF - Journal of Non-Newtonian Fluid Mechanics

SN - 0377-0257

ER -