Drying of a tape-cast layer: Numerical modelling of the evaporation process in a graded/layered material. (December 2016)

• Record Type: Journal Article
• Authors: Jabbari, M.; Jambhekar, V.A.; Hattel, J.H.; Helmig, R.
• Is Part Of: International journal of heat and mass transfer. Volume 103(2016:Dec.)
• Page Start: 1144
• Page End: 1154
• Publication Date: 2016-12
• Subjects: Tape casting -- Drying -- Porous media -- Darcy's law -- Graded/layered materials; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2016.08.073
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Coupled free-flow-porous-media simulation on REV scale. Drying behaviour of graded/layered materials. Numerical results motivated by ceramic tape casting. Abstract: Evaporation of water from a ceramic layer is a key phenomenon in the drying process for the manufacturing of water-based tape cast ceramics. In this paper we present a coupled free-flow-porous-media model on the Representative Elementary Volume (REV) scale for coupling non-isothermal multi-phase compositional porous-media flow — for the ceramic layer — and single-phase compositional laminar free flow — for the air above it. The preliminary results show the typical expected evaporation behaviour from a porous medium initially saturated with water, and water–vapour transport to the free-flow region in accordance with the available results from the literature. We elaborate on and discuss the characteristic drying-rate curve for a single layer ceramic, and compare it with that of a graded/layered ceramic. We, moreover, show the influence of the mean diameter of particles of the porous medium ( d p ) — which directly affects the intrinsic permeability ( K ) based on the well-known Ergun's equation — of each single ceramic layer on the drying behaviour of a graded/layered ceramic.