Consider a very deep triangular duct (deep in the directionperpendicular to the plane of the
paper) made of diffuse gray walls. The cross section of the ductforms an equilateral triangle of
sides 1.5 m each. Two surfaces of the duct namely surface 1 andsurface 2 have emissivities 0.4
and 0.6 and are maintained at 1200 K and 800 K respectively, whilethe third surface (surface
3) is radiatively insulated (re-radiating) and has an emissivity of0.5. For the two dimensional
triangular enclosure as described above, answer thefollowing:
(a) Calculate the total number of view factors and determine theview factor matrix
(b) Determine the net radiation heat transfer from surface 1
(c) Determine the temperature of surface 3
(d) If the emissivity of surface 3 is changed, how will your resultchange?
