Volume 9, Issue 1, 2000

Characterisation of Permeability around a 90^o Corner

Nicolas Laval,¹  E. Murat Sozer and Suresh G. Advani* 

University of Delaware, Mechanical Engineering Department, Newark, DE 19716, USA

¹ Current address: IUP Genie des Systemes Industriels, Mechanical and Materials Engineering Department, UBS 56, Lorient-FRANCE.

* Author to whom correspondence should be addressed.

(Received 10/99 ; 1/00 accepted)

Abstract

One-dimensional mould filling experiments were done in L- and T-shaped moulds with constant flow rate injection, and the pressure history was measured. Transient relationship between the preform permeability along the flow direction and the time derivative of pressure was used to measure the permeability. It was found that the resistance to flow around the bend increased by an order of magnitude within the boundary layer of the 90o bend. A simple resistive model with three different permeabilities could be used to describe the decrease in the permeability around the bend using a corner model and hence one could predict the permeability in the bend region. While considering numerical simulations of complicated geometries with bends, one should account for the variation in the bend section to capture the physics of flow in such structures.