Abstract Liquid Droplet in Contact with a Solid Surface.pdfVIP

1Liquid Droplet in Contact with a Solid Surface S. Maruyama1, T. Kurashige, S. Matsumoto2, Y. Yamaguchi and T. Kimura Department of Mechanical Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan Abstract A liquid droplet in contact with a solid surface was simulated by the molecular dynamics method, in order to study the microscopic aspects of the liquid-solid contact phenomena and phase change heat transfer. Measured ‘contact angle’ was well correlated by the depth of the integrated potential of the surface. The layered liquid structure near the surface was also explained with the integrated potential field. Furthermore, the evaporation and condensation through the droplet were simulated by preparing two solid surfaces with temperature differences on the top and bottom of the calculation domain. Over all heat flux and temperature distributions of droplets were measured. Introduction 1 To whom correspondence should be addressed: e-mail: maruyama@photon.t.u-tokyo.ac.jp 2 Current address: Mechanical Engineering Laboratory, Agency of Industrial Science and Technology /MITI, 1-2 Namiki, Tsukuba, Ibaraki 305, Japan 2 The microscopic mechanism of solid-liquid contact is fundamental to understanding phase change phenomena such as dropwise condensation and the collapse of liquid film on a heated surface. We have applied the molecular dynamics method to understand interphase phenomena, such as surface tension [1,2] and liquid-solid contact [3]. Our previous study [3] demonstrated that the droplet could be regarded as a semi-spherical shape except for a few layers of liquid structure on the surface, and that the cosine of ‘contact angle’ was a linear function of the energy scale of the interaction potential. In this report, by changing more parameters such as the length scale of the interaction potential, system size, and temperature, we give a more general description of the phenomena. As