JCEJ Outstanding Paper Award of 2012

Abstract

Citation: This paper investigated the characteristics of the fluid flow of viscoelastic surfactant solutions in a mixing vessel by flow visualization. In the vicinity of the impeller an actively mixed onion-like structure was found. In addition, it appeared that the impeller region was covered by a network-deformed fluid and an onion-like structure was formed if the elastic force was not much smaller than the inertia force and that the onion-like structure was stable under the condition that the lowest impeller rotation speed. These results included significant new knowledge in the mixing of viscoelastic surfactant solutions. Therefore, this paper was selected as an outstanding paper. "Marangoni Flows in Polymer SolutionDroplets Drying on Heating Surfaces" by Shohei Yasumatsu, Kouichi Nakaso, and Jun Fukai, Kyushu University (Yasumatsu et al., 2012) Citation: This paper experimentally and numerically examines transport phenomena in an evaporating, polymer solution droplet on a heated substrate. The relative influence of each Marangoni force, thermal or solutal, on the internal droplet flow is investigated in this article. The authors demonstrate that both thermal and solutal Marangoni forces are important determining factors for the flow within an evaporating droplet. The authors' numerical method enables one to explore the distribution of momentum, solute concentration, and temperature within a droplet. The study of transport phenomena within evaporating droplets is a difficult and practical problem and the results of this study contribute to further development in the field. Therefore this paper merits the Outstanding Paper Award.3. "Numerical Simulations of a Bubble Rising through a Shear-thickening Fluid" by Mitsuhiro Ohta, Sachika Kimura, Tomohiro Furukawa, Yutaka Yoshida, and Mark Sussman, Muroran Institute of Technology and Florida State University (Ohta et al., 2012) Citation: This paper presents three-dimensional computational results for single bubbles rising through shear-thickening fluids. The simulations are carried out according to a coupled level-set/volume-of-fluid (CLSVOF) method. The authors computationally show that the bubble rise velocity decreases and shape deformation of the bubble is restrained by way of the increase in viscosity resulting from the shear thickening effect. The validity of effective viscosity and effective physical dimensionless numbers are examined for bubble rise motion in the shear-thickening fluids, in addition to