Powder Technology, Vol.206, No.1-2, 161-169, 2011
Direct numerical simulation of solid-liquid-gas three-phase flow: Fluid-solid interaction
A direct numerical simulation (DNS) model for three-phase flow (solid, liquid, and gas) with the main purpose of analysing wet granulation processes is presented in this paper. In the present model, liquid-gas two-phase flow is solved by the constrained interpolation profile (CIP) method developed by Yabe et al. (2001) [1], and the interaction between fluid phases and solid particle phase is taken into account by using the immersed boundary (IB) method developed by Kajishima et al. (2001) [2]. The surface tension as well as the wetting are modelled by using the continuous surface force (CSF) model suggested by Brackbill et al. (1992) [3], and the dynamic contact angle is represented by Fukai's (1995) [4] approach, which selectively uses advancing and receding contact angles depending on the movement of fluid interfaces on a solid surface. The accuracy of the model is examined in terms of (i) the drag force exerted on a single particle, (ii) the drag force exerted on a regular particle array, (iii) the surface tension force, and (iv) the wetting. A number of test simulations have been carried out with different numerical cell sizes, and the results are compared with the reported experimental work and theoretical values. (c) 2010 Elsevier B.V. All rights reserved.
Keywords:Three-phase flow;Direct numerical simulation;Wet granulation;Constrained interpolation;profile (CIP) method;Immersed boundary (IB) method