Experimental measurement of direct thermal radiation through single-layer square-cell plain woven screens

Australian bushfires have killed many people and caused severe damage; like as any other type of disaster. Previous studies have identified direct flame contact and radiant heat as the main cause of fatalities.The role of screens in limiting the radiation exposure on an object by fire on the other side of the screen is well-known, but still it has not been experimentally determined. A screen between a radiation source and an object divides the radiant heat flux into two parts. The first part is direct radiant heat flux that passes directly through the screen without any interaction. The second part is indirect radiation heat flux, which includes both emitted and reflected radiant heat fluxes by the heated screen. This experimental study deals with the direct radiant heat flux, which depends on the screen porosity and is independent of the material composition or the surface quality of the screen. The experimental results of four square cell,plain woven screens with porosities ranging from 41% to 66% show that the passing ratios of direct radiant heat flux through screens are less than those suggested by their porosity. Four empirical equations have been developed to determine the passing ratio of the direct radiation through screens, and tunnel vision angles of the screens