Conduction Toturial

Instructional exercise 1 (Conduction and Convection) 1. Consider a composite structure appeared on beneath. Conductivities of the layer are: k1 = k3 = 10 W/mK, k2 = 16 W/mK, and k4 = 46 W/mK. The convection coefficient on the correct side of the composite is 30 W/m2K. Compute the complete opposition and the warmth course through the composite. (0. 46, 173. 9 W) 2. Think about a 1. 2-m high and 2-m-wide glass window whose thickness is 6 mm and warm conductivity is k= 0. 78W/m. 0C.Determine the consistent pace of warmth move through this glass window and the temperature of its inward surface for a day during which the room is kept up at 24 0C while the temperature of the outside is - 5 0C. Take the convection heat move coefficients on the internal and external surfaces of the window to be h1= 10 W/m2 . 0C and h2 = 25 W/m2 . 0C and dismissal any warmth move by radiation. (471W, 4. 40C) 3. Think about a 1. 2-m-high and 2-m-wide twofold sheet window comprising of two 3-mm-thick layers of glass (k=0. 78 W/m . 0C) isolated by 12-mm-wide stale air space.Determine the consistent pace of warmth move through this twofold sheet window and the temperature of its internal surface for a day during which the room is kept up at 24 0C while the temperature of the outside is - 50C. Take the convection heat move coefficients on the internal and external surfaces of the window to be h1=10 W/m2 . 0C and h2 = 25 W/m2 . 0C and negligence any warmth move by radiation. Given additionally k air = 0. 026 W/m . 0C (114W, 19. 20C) 4. A barrel shaped resistor component on a circuit board disseminates 0. 5W of intensity in a situation at 400C. The resistor is 1. 2 cm long, and has a distance across of 0. 3cm. Expecting warmth to be moved consistently from all surfaces, decide (a) the measure of warmth this resistor scatters during a 24-h period, (b) the warmth motion on the outside of the resistor, in W/m2 and (c) the surface temperature of the resistor for a consolidated convection and radia tion heat move coefficient of 9 W/m2 . 0C. (3. 6 Wh, 1179 W/m2, 1710C) 5. Water is bubbling in a 25-cm-width aluminum skillet (k=237 W/m . 0C) at 95 0C.Heat is moved consistently to the bubbling water in the container through its 0. 5-cm-thick level base at a pace of 800 W. In the event that the internal surface temperature of the base of the dish is 1080C, decide (a) the bubbling warmth move coefficient on the inward surface of the skillet, and (b) the external surface temperature of the base of the container. (1254 W/m2 . 0C, 108. 30C) 6. Steam at 320 0C streams in a tempered steel pipe (k= 15 W/m. 0C) whose internal and external distances across are 5 cm and 5. 5cm, individually. The funnel is secured with 3-cm-thick glass fleece protection (k= 0. 38 W/m. 0C). Warmth is lost to the environmental factors at 50C by common convection and radiation, with a joined characteristic convection and radiation heat move coefficient of 15 W/m2. 0C. Taking the warmth move coefficient inside th e channel to be 80 W/m2. 0C, decide the pace of warmth misfortune from the steam per unit length of the funnel. Likewise decide the temperature drops over the funnel shell and the protection. (93. 9 W, 0. 095 0C, 290 0 C) 7. Consider a 8-m-long, and 0. 22-m-thick divider whose delegate cross area is as given in the Figure 1.The warm conductivities of different material utilized, in W/m. 0C, are kA=kF=3, kB=10, kC=23, kD=15 and kE=38. The left and right surface of the divider are kept up a uniform temperatures of 3000C and 1000C, individually. Accepting warmth move through the divider to be one-dimensional, decide (Given Rcond = x/kA and Rconv = 1/hA) a) The pace of warmth move through the divider. b) The temperature at where the areas B, D and E meet. c) The temperature drop over the segment F. (6453. 0075 W, 259. 59380C, 134. 22220C)