Hot square plate (1 m ×1 m) is to be cooled by attaching aluminum circular pin fins (D=0.25 cm, L= 3 cm) distributed with distance 0.6 cm as illustrated in Figs.(1-a) & (1-b). If the fin base temperature is 100°C, cooling air temperature is 30°C and h= 35 W/m. °C. Determine the total rate of heat transfer from the finned plate and the effectiveness of the fins? Assume k= 237 W/m.°C and nr=tanh mL/ mL.

Troom = 25°C Problem-4: An 8-m-internal-diameter spherical tank made of 1.5-cm-thick stainless steel (k = 15 W/m-K) is used to store iced water at 0°C. The tank is located in a room whose temperature is 25°C. The walls of the room are also at 25°C. The outer surface of the tank is black (emissivity = 1), and heat transfer between the outer surface of the tank and the surroundings is by natural convection and radiation. The convection heat transfer coefficients at the inner and the outer surfaces of the tank are 80 W/m²-K and 10 W/m².K, respectively. Determine (a) the rate of heat transfer to the iced water in the tank and (b) the amount of ice at 0°C that melts during a 24-h period. The heat of the fusion of water at atmospheric pressure is hf5 333.7 kJ/kg. Iced water D D₁= 8 m Tin = 0°C 1.5 cm

Problem: A solid copper cube of 10-cm edge length(p =8954 kg/m³, c = 383 J/kg.K, k= 386 W/m.K) initially at a uniform temperature T;= 250°C is suddenly immersed in a well-stirred fluid which is maintained at a uniform temperature T = 50 °C. The heat transfer coefficient between cube and the fluid h=20O W/m²K. A. Check whether the lumped system analysis is suitable. B. Determine the temperature of the copper block at t= 5 min after the immersion. TE 250°C 10 cm Tm= 50 °C, h=200 w/mk

Q3/ A 6(m) long 2(kW) electrical resistance wire is made of 0.2(cm) diameter stainless steel (k = 15.1 W/m °C). The resistance wire operates in an environment at 30°C with a heat transfer coefficient of 140 (W/m?. °C) at the outer surface. Find the temperature distribution equation and determine the surface temperature of the wire.