Motion of Droplets Induced by the Marangoni Force on a Wall with Temperature Gradient

Abstract

Motion of silicone-oil and water droplets induced by the Marangoni force was numerically simulated by using the two- and three-dimensional second order finite difference methods with the CIP and the level set methods. The surface tension was introduced by using the continuum surface force (CSF) method. The results clearly showed the flow induced by the Marangoni force and the dependence of droplet motion velocity on droplet size, contact angle, temperature gradient, and fluid properties. The Marangoni force balanced with the viscous force in the small contact angle case ; on the other hand, in the large contact angle case, it balanced with the normal component of the surface tension. As for the effect of the fluid properties on the droplet motion, the temperature coefficient of the surface tension had much larger effect than viscosity, thermal diffusivity, and surface tension.