Experimental Study of Pressure Drop-Flow Rate Characteristics of Heated Tight Porous Materials

Abstract

Tight porous materials are used as pneumatic components in a wide range of industrial applications. Such porous materials contain thousands of interconnected irregular micropores, which produce a large pressure drop (ΔP) between the upstream and downstream sides of the porous material when a fluid flows through it. The relationship between the pressure drop and flow rate (i.e., ΔP-G characteristics) is a very important basic characteristic. Temperature is one of the factors that affect the ΔP-G characteristics because variations in temperature change the viscosity and density of the fluid. In this study, we experimentally analyzed the ΔP-G characteristics of tight porous materials by heating them using an electromagnetic system. First, we experimentally investigated the change in the ΔP-G curve under the condition of constant heating power. Then, based on the Darcy–Forchheimer theory, we introduced an experimental method to determine the average temperature of the fluid. The results show that the temperature reaches approximately 500 K in the small flow rate range, which produces considerable changes in the ΔP-G curve. As the flow rate increases, the temperature decreases, and thus, the ΔP-G curve at constant heating power converges to the curve for the room temperature. Furthermore, we compared three porous materials with different permeability coefficients and porosities and analyzed the effect of these parameters on the ΔP-G characteristics. We also performed experiments at different downstream pressures to study the effect of the average density on the ΔP-G characteristics.