Question

5. Two metal sheets, in direct contact, separate two regions with constant (T2 = 32.50 °C and T2 = 18.30 °C, respectively). The dimensions of cross-sectional area where the layers are in contact are: 0.350m x 0.325m. The brass sheet has a thickness of 0.015m and the copper is 0.025m thick. Find the temperature at the interface of the metals. T1 Tz i. # ii. Determine rate of heat flow across the two panels. brass copper

Answer 1

The temperature at the interface will be such that the rate of heal conduction through the two sheet will be Same . t A surface area now, rate of heat conduction - Q KA(T2-T,) where k= thermal conductivity d = thickness let T-temp at interface, then. KA(Ti-T) K₂ AIT-T2) T, = 32.5+273- 305.5 di da T2=(18-3 + 273) = 291-3 The (T. -T) - K 2 (T-T2) for brass - ki = 109.0, and copper = K₂= = 385 5-7) - ( 1-291.3) 109 385 305.5- 0.025 0.015 231 305.5-T - loq XT- 291.3X231 109 OT T1284 +) 305.5+ 291.3 X 231 109 07 Тх 340 109 100589.8 109 67 T = 1005898 340 295.85K = 22.85°C

(9) Heat flow at steady state is 385x Ax ( 295.85 - 291.3) Ho 11 6 .025 385x (-35x0.325) x (295-85-291.3) 0.025 7974.58 Watt