Numerical Simulation and Experimental Study on Unsaturated Flow Behavior in Porous Media

摘要

Liquid Composite Molding (LCM) such as Resin Transfer Molding (RTM) is becoming more preferred in the composite manufacturing industry due to its versatility and economics among other merits. In case of liquid composite molding, the presence of voids is detrimental to the performance of finished parts, and understanding of the resin flow in the porous preform is very important. The main reason for void formation is the velocity discrepancy between the tow zones and the open zones depending on the capillary number. In analyzing the flow through a porous medium, Darcy's law is the most generally accepted approach for analyzing flow through porous medium. According to this law, the flow rate is proportional to the pressure gradient in porous media, and the proportionality coefficient is the permeability, which is regarded as a property of the medium. However, in many practical cases, permeability values were found to vary depending on the flow conditions such as the flow rate.