The figure shows (in cross section) a wall that consists of four layers. The the
ID: 2148535 • Letter: T
Question
The figure shows (in cross section) a wall that consists of four layers. The thermal conductivities are k1 = 0.060 W/m*K, k3 = 0.040 W/m*K and k4 = 0.120 W/m*K (k2 is not known). The layer thicknesses are L1 = 2.6 cm, L3 = 2.4 cm and L4 = 1.4 cm. The hottest temperature on the extreme left is 30?C while the coldest is on the extreme right at -10?C. If we number the temperatures at the interfaces between different materials as 12, 23, 34, then T12 = 25?CWhat is T23? That is the ratio of k2 to L2?
Explanation / Answer
T23=-6.3462 C K2/L2=0.3681