Air flow through two layered mesh at varying porosity and spacing

Abstract

[Abstract]: Metal meshes have a number of applications such as security screens, fencing, screening, filtration, equalization of flow, heat processing etc. They are available in different materials, element shapes, sizes and weavings. The work presented here examines the drag force on the metal meshes as it is particularly important if a large size mesh is used at high wind velocities. The flow of air through cells in a mesh such as perforated (holes drilled in a sheet metal) or woven wire encounters drag force and a pressure drop. This effect of pressure drop associated with the mesh is not desirable in certain applications such as uniform supply of hot air in turbine using the resistance of wire mesh to increase the internal energy of air molecules as an attempt to increase the overall efficiency of turbine. But the added wire mesh faces large drag force at higher wind velocities and since it is at high temperature that makes it vulnerable to tear apart. Various researches have carried work to establish empirical relationships of flow around cylinders when placed in wind tunnel, but hardly any attempt has been made to study air flow through two layers of mesh separated by a finite distance. The work presented here is experimental and intended to investigate the effect of using two layers of mesh on the drag force by using mesh of varying porosity and at different spacing, with a probability to lower the net drag force than that obtained by using single mesh.