PERMEABILITY MEASUREMENTS IN EXPERIMENTS ON CONVECTIVE HEAT TRANSFER IN A COMPLEX FIBROUS POROUS MEDIUM STRUCTURED BY A 3D PHOTOPOLYMER FRAMEWORK

Abstract

The paper is devoted to the experimental study concerning the properties of a complex fibrous porous medium. The medium consists of cylindrical fibers structured by a 3D photopolymer framework. Three porous samples with the porosities of 0.77, 0.82, and 0.88 are manufactured. An alternative method has been developed for determining the permeability of samples. It is based on the measurements of convective heat transfer in a horizontal porous layer saturated with fluid under the gravitational field. The values of permeability are found for the investigated samples by the two formulas which are derived through the Darcy and Darcy-Brinkman models and include our experimental data. Agreement between the permeability values obtained by the two different models is achieved. It is shown that the permeability of the complex fibrous porous medium grows with decreasing the solid volume fraction of functional fibers and tends to the value of the permeability of the 3D photopolymer framework. The permeability of the 3D photopolymer framework is evaluated independently of the method presented in the paper.