To defrost ice accumulated on the outer surface of an automobile windshield, warm air is blown over the inner surface of the windshield. Consider an automobile windshield with thickness of 5 mm and thermal conductivity of 1.8 W/m-K. The outside ambient temperature is -10°C and the convection heat transfer coefficient is 200 W/m2.K, while the ambient temperature inside the automobile is 25°C. Determine the value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield necessary to cause the accumulated ice to begin melting. L = 5 mm Outside air, -10°C ho=200 W/m².K Windshield Inside air, 25°C T₁ = 0°C The value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield is W/m2.°C.

To defrost ice accumulated on the outer surface of an automobile windshield, warm air is blown over the inner surface of the windshield. Consider an automobile windshield with thickness of 5 mm and thermal conductivity of 1.8 W/m-K. The outside ambient temperature is -10°C and the convection heat transfer coefficient is 200 W/m2.K, while the ambient temperature inside the automobile is 25°C. Determine the value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield necessary to cause the accumulated ice to begin melting. L = 5 mm Outside air, -10°C ho=200 W/m².K Windshield Inside air, 25°C T₁ = 0°C The value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield is W/m2.°C.

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.

Chapter2: Steady Heat Conduction

Section: Chapter Questions

Problem 2.38P: 2.38 The addition of aluminum fins has been suggested to increase the rate of heat dissipation from...

See similar textbooks

Similar questions

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.
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.
1.19 A cryogenic fluid is stored in a 0.3-m-diameter spherical container is still air. If the convection heat transfer coefficient between the outer surface of the container and the air is 6.8 , the temperature of the air is 27°C, and the temperature of the surface of the sphere is –183°C, determine the rate of heat transfer by convection.
A cooling system is to be designed for a food storage warehouse for keeping perishable foods cool prior to transportation to grocery stores. The warehouse has an effective surface area of 1860 m2 exposed to an ambient air temperature of 32C. The warehouse wall insulation (k=0.17W/(mK)) is 7.5 cm thick. Determine the rate at which heat must be removed (W) from the warehouse to maintain the food at 4C.
To defrost ice accumulated on the outer surface of an automobile windshield, warm air is blown over the inner surface of the windshield. Consider an automobile windshield with thickness of 5 mm and thermal conductivity of 1.4 W/m K. The outside ambient temperature is -10°C and the convection heat transfer coefficient is 200 W/m2-K, while the ambient temperature inside the automobile is 25°C. Determine the value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield necessary to cause the accumulated ice to begin melting. L-5 mm Outside air, -10°C h, = 200 W/m²-K Windshield k= 1.4 W/m-K Inside air, 25°C AAAA T; = 0°C FIGURE P17-37
The inside surface of an insulation layer is maintained at 350oC and the outside surface dissipatesheat by convection and radiation to air and wall, respectively. The temperatures of air and wall are 15 oC.The insulation layer has a thickness of 10 cm and a thermal conductivity of 15 W/m.K. What is the value ofthe heat transfer coefficient at the outside surface of the layer, if the temperature at the outside surfaceshould not exceed 225 oC? (The emissivity and the width of the surface are 0.3 and 1 m., respectively.=5.67x10-8 W/m2K4).
700 W/m3 electrical heat is generated in a large plane wall whose one side is insulated while the other side is subjected to convection. The thermal conductivity of the wall is (k W/m.K) and the convection heat transfer coefficient is (h = 17 W/m?K). Determine the location and the value for the maximum temperature and the minimum temperature in the plate for steady one-dimensional heat transfer. Assume T. = 25°C. A=1 m?; L= 25 cm). = 20
Exhaust gases from a manufacturing plant are being discharged through a 10-m tall exhaust stack with outer diameter of 1 m wall thickness of 0.2 m, and thermal conductivity of 40 W/m-K. The exhaust gases are discharged at a rate of 1.2 kg/s while temperature drop between inlet and exit of the exhaust stack is 30°C, and the constant pressure specific heat of the exhaust gases is 1600 J/kg-K. On a particular day, the outer surface of the exhaust stack experiences radiation with the surrounding at 27°C, and convection with the ambient air at 27°C also, with an average convection heat transfer coefficient of 8 W/m2K. Solar radiation is incident on the exhaust stack outer surface at a rate of 150 W/m2, and both the emissivity and solar absorptivity of the outer surface are 0.9. Exhaust stack wall A-40 W/mK And m Exhaust gases Exhaust stack a, -8=0.9 Air, 27°C A-8 W/m²K T-T-30°C K Manufacturing plant Determine the inner surface temperature of the exhaust stack (up to 1 decimal place). The…
Warm air is blown over the inner surface of the windshield of an automobile to defrost ice accumulated on the outer surface. The windshield has a thickness of 5 mm and thermal conductivity of 1.4 W/m-K. The outside ambient temperature is -10°C and the convection heat transfer coefficient is 200 W/m2-K, while the ambient temperature inside the automobile is 25°C. Determine the value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield necessary to cause the accumulated ice to begin melting.
QUESTION 3: Warm air is blown over the inner surface of the windshield of an automobile to defrost ice accumulated on the outer surface. The windshield has a thickness of 5 mm and thermal conductivity of 1.4 W/m-K. The outside ambient temperature is -10°C and the convection heat transfer coefficient is 200 W/m²-K, while the ambient temperature inside the automobile is 25°C. Determine the value of the convection heat transfer coefficient for the warm air blowing over the inner surface of the windshield necessary to cause the accumulated ice to begin melting.
In a thermal power plant, a horizontal copper pipe of "D" diameter, "L" length and thickness 1.7 cm enters into the boiler that has the thermal conductivity as 0.3 W/mK. The boiler is maintained at 107degreeC and temperature of the water that flows inside the pipe is at 31degreeC. If the energy transfer (Q) is 124925 kJ in 7 hours. Determine the Heat transfer rate, Surface area of the pipe and Diameter & Length of the pipe, if D = 0.012 L.Change in Temperature (in K) Heat Transfer Rate (in W) Surface Area of the Pipe (m2) Pipe Length (in m) Pipe Diameter (in mm)
Rock has often been suggested as a medium for the thermal storage of energy.A cylindrical piece of rock with diameter 10 m and height 20 m is used for thestorage of thermal energy. The rock is insulated and has an average heattransfer coefficient, U = 0.28 kW/m2 K. The density of the rock material is2,650 kg/m3 and its specific heat capacity is 0.72 kJ/kgK. The temperature ofthe rock is raised to 500C and the ambient temperature is 25C. Determine:a) The total energy stored in the rock in MWh.b) The temperature of the rock 12 h after the heating process stops.c) The heat that has escaped from the rock during this 12 h period.d) The loss of exergy of the rock during this 12 h period.