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The heat flux that is applied to the left face of a plane wall is
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Introduction to Heat Transfer
- A plane wall 15 cm thick has a thermal conductivity given by the relation k=2.0+0.0005T[W/mK] where T is in kelvin. If one surface of this wall is maintained at 150C and the other at 50C, determine the rate of heat transfer per square meter. Sketch the temperature distribution through the wall.arrow_forwardThe rate of heat conduction through a plane wall is proportional to the average thermal conductivity, the wall area, and the temperature difference, but is inversely proportional to the ---------------.arrow_forwardThe thermal conductivities of human tissues vary greatly. “Fat” and “skin” have conductivities of approximately 0.200 W /m 0K and 0.0200 W /m 0K, respectively, while other “tissues” inside the body have conductivities of approximately 0.500 W /m 0 Assume that between the core region of the body and the skin surface lies a “skin” layer of 1.00mm, a “fat” layer of 0.500 cm., and 3.20 cm. layer of other “tissues”. Find the rate of energy loss when the core temperature is 37.00C and the exterior temperature is 0.000 Assume a body area of 2.00 m2. (Both a protective layer of clothing and an insulating layer of unmoving air are absent).arrow_forward
- The fin efficiency is defined as the ratio of the actual heat transfer from the fin to a. The heat transfer from an equivalent fin which is infinitely long b. The heat transfer through the base area of the same fin c. The heat transfer from the same fin with an adiabatic tip d. The heat transfer from the same fin if the temperature along the entire length of the fin is the same as the base temperaturearrow_forwardThe inside surface temperature of a glass oven door (0.5 m x 0.5 m x 0.001 m) is 180°C, the outside surface temperature is 25°C, and the thermal conductivity of glass is 1.4 W/(m•K) What is the rate of heat transfer?arrow_forwardOver the outside part of the room window, the wind is blowing with a speed of 10 m/sec. Due to this wind motion, the temperature on the outer surface of the window is 5 degrees lower than the room temperature. Determine the convective heat flux if the wind temperature is 10 C with a heat transfer coefficient of 10 W/(mK). Accept the temperature inside the room as 25 C. A) 200 W B) 100 W C) 200 W/(m^2) D) 100 W/(m^2) E) Not sufficient informationarrow_forward
- A steel pipe (outside diameter 100 mm) is covered with two layers of insulation. The inside layer, 40 mm thick, has a thermal conductivity of 0.07 W/(m K). The outside layer, 20 mm thick, has a thermal conductivity of 0.15 W/(m K). The pipe is used to convey steam at a pressure of 600 kPa. The outside temperature of insulation is 24°C. If the pipe is 10 m long, determine the following, assuming the resistance to conductive heat transfer in steel pipe and convective resistance on the steam side are negligible: a. The heat loss per hour. b. The interface temperature of insulation.arrow_forwardThe block in the drawing has dimensions L0×2L0×3L0,where L0 =0.5 m. The block has a thermal conductivity of 300 J/(s·m·C˚). In drawings A, B, and C, heat is conducted through the block in three different directions; in each case the temperature of the warmer surface is 36 ˚C and that of the cooler surface is 6 ˚C Determine the heat that flows in 6 s for each case.arrow_forwarda pipe with an outside diameter of 2.5 inches is insulated with 2 inches layer of asbestos ( K= 0.396(btu-in)/(hr-ft-F) followed by a layer of cork 1.5 inches thick ( K= 0.30 (btu-in)/ft (hr-ft-F). if the temperature of the outer surface of the cork and pipe is 90 F and 290 F RESPECTIVELY, calculate the heat loss per 100 ft of insulated pipe in btu/hrarrow_forward
- 9. A plane wall 6.2 cm thick generates heat internally. The wall is made of a material with thermal conductivity of 50 W/m K. Both faces of the wall are maintained at 52.50°C. If the maximum temperature inside the wall is 61.5°C, what is the rate of internal heat generation in the wall per unit volume? Express your answer in W/m³.arrow_forwardA spherical container with an inner radius r1 = 1 m and an outer radius r2 = 1.05 m has its inner surface subjected to a uniform heat flux of q1=7kw/m^2. The outer surface of the container has a temperature T2 = 25°C, and the container wall thermal conductivity is k = 1.5 W/m·K. Show that the variation of temperature in the container wall can be expressed as and determine the temperature of the inner surface of the container at r = r1.arrow_forwardThe roof of an electrically heated house is 7 m long, 10 m wide, and 0.25 m thick. It is made of a flat layer of concrete whose thermal conductivity is 0.92 W/m·°C. During a certain winter night, the temperatures of the inner and outer surfaces of the roof were measured to be 15°C and 4°C, respectively. The average rate of heat loss through the roof that night was (a) 41 W (b) 177 W (c) 4894 W (d) 5567 W (e) 2834 Warrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning