Measurement of principal permeability with the channel flow experiment

A framework for channel flow permeability measurement in resin transfer molding (RTM) is developed in this paper. For the channel flow experiment, five possible experimental configurations are identified, of which two have not yet been mentioned in the literature. Starting from effective permeability, the entity measured in the experiment, explicit formulas for principal permeability and its orientation in two and three dimensions are developed. These formulas are applied to (published) experimental results that demonstrate their validity. The practical problems that prevent three-dimensional permeability measurement are discussed. Next, a framework for two-dimensional channel flow permeability measurement is proposed. All known channel flow permeability measurement methods are classified according to this new framework, and where appropriate, differences are discussed. An important finding emerging from this comparison is that two different definitions of Darcy's law are used today in permeability measurement.