A radiative heater consists of a bank of ceramic tubes with internal heating elements. The tubes are of diameter D = 20 mm and are separated by a distance s = 50 mm. A reradiating surface is positioned behind the heating tubes as shown in the schematic. Reradiating Heating element T,n Material T,m Determine the net radiative heat flux, in W/m, to the heated material when the heating tubes (h = 0.87) are maintained at 1000 K. The heated material (m = 0.26) is at a temperature of 500 K. q" = i ! W/m