For a metal plate (k = 50 W/m°C and a = 0.000030 m^2 / s) that is at a uniform initial temperature of 90 °C, and which is exposed to a current of air at 20°C with a heat transfer coefficient of 210 W/ m2°C on the surface, determine the temperature at the surface and at a depth of 10 cm after 3 minutes of exposure. Assume a semi-infinite surface, one- dimensional conduction, and constant thermophysical properties

For a metal plate (k = 50 W/m°C and a = 0.000030 m^2 / s) that is at a uniform initial temperature of 90 °C, and which is exposed to a current of air at 20°C with a heat transfer coefficient of 210 W/ m2°C on the surface, determine the temperature at the surface and at a depth of 10 cm after 3 minutes of exposure. Assume a semi-infinite surface, one- dimensional conduction, and constant thermophysical properties

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.16P: 3.16 A large, 2.54-cm.-thick copper plate is placed between two air streams. The heat transfer...

See similar textbooks

Similar questions

2.55 A long, 1-cm-diameter electric copper cable is embedded in the center of a 25-cm-square concrete block. If the outside temperature of the concrete is 25oC and the rate of electrical energy dissipation in the cable is 150 W per meter length, determine temperatures at the outer surface and at the center of the cable.
Heat is transferred at a rate of 0.1 kW through glass wool insulation (density=100kg/m3) with a 5-cm thickness and 2-m2 area. If the hot surface is at 70C, determine the temperature of the cooler surface.
2.38 The addition of aluminum fins has been suggested to increase the rate of heat dissipation from one side of an electronic device 1 m wide and 1 m tall. The fins are to be rectangular in cross section, 2.5 cm long and 0.25 cm thick, as shown in the figure. There are to be 100 fins per meter. The convection heat transfer coefficient, both for the wall and the fins, is estimated to be K. With this information determine the percent increase in the rate of heat transfer of the finned wall compared to the bare wall.
3.16 A large, 2.54-cm.-thick copper plate is placed between two air streams. The heat transfer coefficient on one side is and on the other side is . If the temperature of both streams is suddenly changed from 38°C to 93°C, determine how long it takes for the copper plate to reach a temperature of 82°C.
Two rods ( fins) having same dimensions , one made of brass ( k = 85 Wm K) and the other of copper ( k = 375 W/m K ) , having one of their ends inserted into a furnace . At a section 10.5 cm a way from the furnace , the temperature of brass rod 120oC . Find the distance at which the same temperature would be reached in the copper rod ? both ends are exposed to the same environment .
A large steel plate (1.0% carbon) 5.0 cm thick is initially at a temperature of 425 °C. It is suddenly exposed on both sides to a convective environment with h = 285 W/m² °C, and T. = 65 °C. Determine the centerline temperature and the temperature inside the body 1.25 cm from the surface after 24 minutes. k= 41 W/m-K a = 1.172 × 105 m²/s (at 20 °C)
Liquid flows in a metal pipe with an inner diameter of D1 = 22 mm and an outer diameter of D2 = 32 mm. The thermal conductivity of the pipe wall is 12 W/m-K. The inner surface of the pipe is coated with a thin polyvinylidene chloride (PVDC) lining. Along a length of 1 m, the pipe outer surface is exposed to convection heat transfer with hot gas, at To = 100°C and h= 5 W/m².K, and thermal radiation with a surrounding at Tsurr = 100°C. The emissivity at the pipe outer surface is 0.3. The liquid flowing inside the pipe has a convection heat transfer coefficient of 50 W/m²K. If the outer surface of the pipe is at 85°C, determine the temperature at the PVDC lining and the temperature of the liquid.
A steam is flowing through a 5.7 m long of steel tube that has inner and outer radii of r, = 0.015 and r, 0,024 m, and a thermal conductivity of 0.14 W/m.K. The steam and the outer surface of the tube is maintained at constant temperature of 150 °C and the air = 25 °C, h = 0.35 W/m2.k) is surrounding the tube. To prevent the outer surface of the steel from the environmental conditions, a material that has a thermal conductivity of 0.014 W/m.k is wrapped over the outer surface of the steel. What is the maximum heat transfer from the steam to the air (W)? NOTE: Enter your answer. Answer Air Th Steam Steel Tr 111 To
Q2/ A 3-m internal diameter spherical tank made of 2-cm-thick stataless steel (k= 15 W/m 0°C. The tank is located in a room whose %3D C) is used to store iced water at Te temperature is T-22°C. The walls of the room are also at 22°C. The outer surface of the tank is black 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 h-80 W/m2 C and h 10 W/m2 C, 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.
A long 20 cm diameter shaft made of stainless steel 304 comes out of an oven at a uniform temperature of 600°C. The shaft is then allowed to cool slowly in an environment at 200°C with an average heat transfer coefficient of h = 80 W/m².K. Determine [a] the temperature at the center of the shaft and [b] the temperature of the outer surface of the shaft 45 minutes after the start of the cooling Given: Find: Schematic: Assume: Property Data: k= 14.9 W/m°C p= 7900 kg/m³ Cp = 477 J/kg:K a= 3.95 x 10-6 m²/s
Its thickness is 1.18 m, its thermal conductivity is 2.75 W/m.°C and its surface area is 15m2Consider a wide plane wall. Inside of the base plateThere is a uniform heat flux produced on its surface with the help of the resistance wire inside.590 W/m2 on the left surface of the wall at x=0net heat fluxand the temperature on this surface was measured as 590 °C. On the wallassuming that there is no heat generation and that the thermal conductivity is constant;a) The differential equation for continuous one-dimensional heat conduction in the wall, andSet the boundary conditions.b) Solve the differential equation to obtain a relation for the temperature change at the wall.c) Calculate the heat loss rate from the wall.
Nuclear wastes are packed in a long, cylindrical container. The wastes steadily generate energy at auniform rate of 2.0 W/cm^3. If the container surface is cooled by convection of a water coolant at 30oC, determine the surface temperature of the container. The container diameter, d = 2 cm, and the heat transfer coefficient is 290 W/(m^2*K). Heat transfer by radiation from the surface is expected to be negligible.