A cylinder, 12 cm high and 8 cm in diameter, k = 12.5 W/mK, maintained at 36 ºC, is to be placed horizontally inside an environment filled with air at 1 atm and 4 ºC. What is the convection heat transfer rate between the cylinder and the air? (Note: assume the cylinder is surrounded by air at 4 ºC, and neglect heat transfer through the left and right end surfaces.)
A cylinder, 12 cm high and 8 cm in diameter, k = 12.5 W/mK, maintained at...
Cold conditioned air at 10°C is flowing inside a 1.5 cm thick square aluminum (k = 240 w/mK) duct of inner cross section of 25x25cm at a mass flow rate of 1.0 kg/s. The duct is exposed to air at 35°C with a combined convection-radiation heat transfer coefficient of 15 W/m2K. The convection heat transfer coefficient at the inner surface is 75 W/.m2.K. If the air temperature in the duct should not increase by more than 1°C determine the maximum...
(13) A brewery fermentation tank 12 m in diameter is situated in a room, which has a temperature of 15°C. The tank is constructed of 10-mm welded steel plate with 12-mm glass lining. The temperature at the inner surface of the glass lining is 50°C. Assume that the convective resistance offered by the air film on the outside of the tank equals the combined resistance of the glass and steel. The thermal conductivity of glass is 0.80 W/mK and that...
A long cylinder of diameter D 0.012 m, thermal conductivity k 358 W/(mK), density p - 7614 kg/m3, specific heat c 418 J/(kgK) is initially at a uniform temperature of Ti-74°C. The cylinder is suddenly exposed to a gas at T,-18 ℃ The convection coefficient is h -17 W/(m2K). Verify that a lumped capacitance analysis can be used for the transient response of the cylinder temperature. What is the time t in seconds for the cylinder temperature to become Tf-32...
A truncated cone 30 cm high is constructed of aluminum [k = 204 W/m 0C]. The diameter at the top is 7.5 cm, and the diameter at the bottom is 12.5 cm. The lower surface is maintained at 93 °C; the upper surface, at 540 °C. The other surface is insulated. Assuming one dimensional heat flow, what is the rate of heat transfer in watts?
please help me ASAP 2. [10] COI A steel tube (ks - 43.26 W/mK) of 5.08 cm inner diameter and 7.62 em outer diameter is covered with 2.5 cm layer of insulation (k, -0.208 W/mK) the inside surface of the tube receivers heat from a hot gas at the temperature of 316°C with heat transfer co-efficient of 28 W/mK. While the outer surface exposed to the ambient air at 30°C with heat transfer co- efficient of 17 W/mK. Calculate heat...
H8-1: 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 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. Radiatior heat transfer is negligible. Determine the rate of heat transfer to the iced water in the tank. room 25°0c T. Iced water 0...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k = 237 W/ mK. (T..+) The thermal conductivity of water at the film temperature of T, = =(60°C + 20°C)/2 = 40°C is kfluid = 0.631 W/mK. 1. value...
A 15 cm diameter, 2 cm thick sight glass installed in the wall of a glass fired boiler allows the operator to observe conditions inside the boiler during operation. During normal boiler operation, the inside surface of the sight glass is 130C. Due to natural convection current in the warm boiler room, air at 35C flows vertically across the outside surface of the sight glass, giving the heat transfer coefficient of 25 ?/?2 ?. The sight glass is made of...
Thermal Resistance Analysis: Consider a 1.2 m high and 1.4 m wide double-pane window consisting of two 4 mm thick layers ofglass (k-0.85 W m-K) separated by a 8-min stagnant air space. (k= 0.025 W m-K) Determine the steady rate of heat transfer through this double-pane window and the temperature of its inner and outer surfaces on a day when the inside room temperature is maintained at 20 °C and the outside ambient temperature is 32 °C. Assume the convection...
4-79 White potatoes (k0.50 W/m-K and 0.13 X 10-6 m/s) that are initially at a uniform temperature of 25°C and have an average diameter of 6 cm are to be cooled by refrigerated air at 2°C flowing at a velocity of 4 m/s. The average heat transfer coefficient between the potatoes and the air is experimentally determined to be 19 W/m2.K Determine how long t wl take for the center temperature of the potatoes to drop to 6°C. Also, determine...