Experimental determination of circulation velocities inside drops

Abstract

Velocities inside large drops suspended in a fluid flowing upward in a tapered glass tube were measured by darkfield particle trace photography. Drop Reynolds numbers were between 3.76 and 19. There was a slow decay of internal velocity and a change in circulatory pattern with the accumulation of minute amounts of colloidal impurities at the interface. The evidence indicates that streamlines leave the interface over the entire rear hemisphere of the drop as circulation is damped.

The Effect of Surfactant on the Motion of a Buoyancy-Driven Drop at Intermediate Reynolds Numbers: A Numerical Approach

“…In solving the momentum equations, the implicit-explicit ADI algorithm is used to discretize Eqs. [9] to [12], and the same algorithm was depicted in detail in (21,28,34).…”

“…The boundary conditions for Eqs. [9] through [12] become the following: On the axis of symmetry (η 1 …”

“…When the interfacial velocity is retarded uniformly over the droplet surface, the dimensionless terminal and interfacial velocities were expressed by Eqs. [12] and [42] …”

Simulating sedimentation of liquid drops

“…Further experimental works on the investigation of the behaviour of a liquid drop in an unbounded flowing fluid were carried out by many researchers including Pruppacher and Beard [3] and Horton et al [4]. The common findings of these studies show the difficulties in the experimental investigation of a liquid drop because of its small size.…”

VOF Simulation Studies on Single Droplet Fluid Dynamic Behavior in Liquid–Liquid Flow Process

“…Garner and Skelland (1955), Calderbank and Korchinski (1956), and Horton et al (1965) examined the influence of circulation inside drops on the drag coefficient and masstransfer rate. Clift et al (1978) conducted several studies on drop deformation and dynamic behavior.…”