Question

A furnace has the form of a truncated conical section, perfectly insulated with an emissivity of 0.3. Assume that all the surfaces are diffuse-gray. s shown in the schematic. The floor of the furnace hasa emissivity of e 0.7 and is maintained at 1000 K with a heat flux of 2200 W/m2, The lateral wall is D 20 mm A L 50 mm A D, 40 mm (a) Determine the temperature of the upper surface, T, if its emissivity is a 0.5. What is the temperature of the lateral wall, T? (b) If conditions for the furnace floor remain unchanged, but all surfaces are black instead of diffuse-gray, determine T, and T. From the diffuse and black-body enclosure analyses, what can you say about the influence of e on your results?

Answer 1

D 20mm Upper surface () Latral Sofa at) Somm Adiabatic wall Futnau floor A T1000k D= 40mm R200 W ur Juryale encletue wut the Surfa ce enrgy balancu, to find the radiosities of the thue suyaCes Foy the thrie nadiatien E-J J,-T J- 1 Ais J-J Eb3 J2-71 49/03-1) ohue the backbady emitive pouseu + - 7(3 of the =T with s67 XID Jom

The Net radiation keaving 1, J, 2200x TT(a.04 子6 adiabatic Sinte the latiral Swa C 11 retognize Es outcome of the , but will for which find at the enclosure we an as N 3 there ase N-9 For view factors, for which digectly detomined NN-1) must be と3 relationg ,ue fore ping With the detmine the tive unkrouns Can and E3 Eb, tamperaturer and wil be The evaluatid frem the sulation 1 a) Difury 45.30 53.48 986 Ss. 76 of 95 46-24 S442 950 b) Bla ck 990