Start-up behavior of viscoelastic fluid flow near a capillary entry.
The effect of elasticity on the capillary entry flow development process was investigated by applying a laser doppler velocimeter (LDV) and flow visualization. The fluid filling the test section was kept at rest under a pressure of compressed air or a natural head and then a valve below the capillary was quickly opened to start the flow. Although the development of the capillary entry flow field of a Newtonian fluid is virtually quasi-steady, it takes a considerable time for a viscoelastic PAA-solution to attain its terminal regime. The transient behavior of the flow rate of the PAA-solution is attributed to the gradual development process of the flow field upstream from the entry.
Shirakashi
Masataka
M
Department of Mechanical Engineering, Nagaoka University of Technology, Niigata, Japan.
Takahashi
Tsutomu
T
Watanabe
Atsushi
A
Aruga
Yohsuke
Y
D002197:Capillary Action; D004548:Elasticity; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D017078:Laser-Doppler Flowmetry / Q000379:methods; D012212:Rheology; D012996:Solutions; D014783:Viscosity; D014867:Water / Q000737:chemistry
D012996:Solutions; D014867:Water