Improvements in the Characterisation of Permeability and Inertial Factor of Insect-Proof Screens through Pressure Drop Coefficients

Abstract

Permeability and inertial factor are the most relevant variables in the Forchheimer equation. They are important to estimate pressure drop when a fluid flow is passing through a porous media. However, in the insect-proof screens field, the existing models to date are still providing a poor predictive accuracy, in part due to they are based on 2D porosity of screens. This work provides novel models for permeability and inertial factor, which are developed from experimental data of insect-proof screens in a wind tunnel and the analytical estimation of 3D porosity. Instead of fitting models directly on observed training data values of permeability and inertial factor, we propose to focus the modelling efforts on finding models dependent on the 3D porosity through the constants in the pressure drop of Forchheimer equation. Since two screens can have the same 2D porosity but different 3D porosity, this makes also models more reliable. The combination of all these aspects has led to parametric models that overcome by far predictions by previous models in the literature.

Keywords

• insect-proof screens
• permeability
• aerodynamic characterisation
• inertial factor
• porous medium