1-88 Consider a 20-cm-thick granite wall with a thermal con- ductivity of 2.79 W/m-K. The temperature of the left surface is held constant at 50°C, whereas the right face is exposed to a flow of 22°C air with a convection heat transfer coefficient of 15 W/m2-K. Neglecting heat transfer by radiation, find the right wall surface temperature and the heat flux through the wall. Granite :k= 2.8 W/m-K T = 22°C T = 50°C h = 15 W/m²-K 20 cm

1-88 Consider a 20-cm-thick granite wall with a thermal con- ductivity of 2.79 W/m-K. The temperature of the left surface is held constant at 50°C, whereas the right face is exposed to a flow of 22°C air with a convection heat transfer coefficient of 15 W/m2-K. Neglecting heat transfer by radiation, find the right wall surface temperature and the heat flux through the wall. Granite :k= 2.8 W/m-K T = 22°C T = 50°C h = 15 W/m²-K 20 cm

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.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.19P: 1.19 A cryogenic fluid is stored in a 0.3-m-diameter spherical container is still air. If the...

See similar textbooks

Similar questions

What are the important modes of heat transfer for a person sitting quietly in a room? What if the person is sitting near a roaring fireplace?
1.29 A spherical interplanetary probe with a 30-cm diameter contains electronic equipment that dissipates 100 W. If the probe surface has an emissivity of 0.8, what is its surface temperature in outer space? State your assumptions in the calculations.
Show that the rate of heat conduction per unit length through a long, hollow cylinder of inner radius ri and outer radius ro, made of a material whose thermal conductivity varies linearly with temperature, is given by qkL=TiTo(rori)/kmA where Ti = temperature at the inner surface To = temperature at the outer surface A=2(rori)/ln(ro/ri)km=ko[1+k(Ti+To)/2]L=lenthofcyclinder
Steam at 320°C flows in a stainless steel pipe (k = 15 W/m-°C) whose inner and outer diameters are 5 cm and 5.5 cm, respectively. The pipe is covered with 3-cm-thick glass wool insulation (k = 0.038 W/m-°C). Heat is lost to the surroundings at 5°C by natural convection and radiation, with a combined natural convection and radiation heat transfer coefficient of 15Wm2-°C. Taking the heat transfer coefficient inside the pipe to be 80 W/m2-°C, determine the rate of heat loss from the steam per unit length of the pipe. Also determine the temperature drops across the pipe shell and the insulation.
A hot steel plate with a surface area of 1.93 m2 and a constant surface temperature of 169°C is exposed to ambient air at 21°C. If the convection heat transfer coefficient is 17.1 W/m2· K, what is the rate of heat transfer (in W) from the plate to the air [round your final answer to zero decimal places]?
Refractory bricks are used as linings for furnaces, and they generally have low thermal conductivity to minimize heat loss through the furnace walls. Consider a thick furnace wall lining with refractory bricks (k = 1.0 W/m·K and a = 5.08 * 10-7 m2/s), where initially the wall has a uniform temperature of 15°C. If the wall surface is subjected to uniform heat flux of 20 kW/m2, determine the temperature at the depth of 10 cm from the surface after an hour of heating time.
A fan forces air over a computer circuit board with an area of 0.01 m2 to keep the circuit board cool. If the temperature of the surface is at 350 K and the incoming air is at 298 K, determine the rate of heat transfer in W. Assume the heat transfer coefficient is 20 W/(m2K). Report your answer to one decimal place.
1. Consider a person standing in a room at 25°C. Determine the total rate of heat transfer and the heat transfer coefficient from this person if the exposed surface area and the skin temperature of the person are1.7 m 2 and 33°C, respectively, and the convection heat transfer coefficient is 5 W/m 2 · °C. Take the emissivity of the skin and the clothes to be 0.9, and assume the temperature of the inner surfaces of the room to be the same as the air temperature. (complete solution thank you)
A wall of length "L" m and height "H" m is made from a thick bricklayer of 38 cm with thermal conductivity of 0.57 W/mK is subjected to heat transfer due to the outside temperature as 35 oC and inside temperature 28 oC. If the energy loss is 10465 kJ in 11 hours. Determine the Heat transfer rate, Surface Area and Length and Height of the wall, if L = 3.5 H. Solution: i) Heat Transfer Rate (in Joule/Sec) = ii) Surface Area of the Wall (in m2) = iii) Height of the Wall (H in m) = iv) Length of the Wall (L in m) =
Max likes to drink tea. He uses his kettle to heat 1.6 liters of water from 18°C to 100°C every day. What does it cost him to heat the water per year (365 days) if he pays 29 cents per kWh of electricity. State the costs in euros to two decimal places. The material values of water averaged for the swept temperature range are: Cwater=4.18 kJ/(kg-K); pwater=983 kg/m3; Awater=0.654 W/(m2. K); nwater=467-10-6 kg/(m-s).
The inside and outside surfaces of a 1-cm thick, 4-m squared-shaped window glass in winter are 9°C and 1°C, respectively. If the thermal conductivity of the glass is 0.78 W/m-K, determine the heat loss, in kcal, through the glass over a period of 8 hours.
Steam at 280° C flows in a stainless steel pipe (k = 15 W/m⋅K) whose inner and outer diameters are 5 cm and 5.5 cm, respectively. The pipe is covered with 3-cm-thick glass wool insulation (k = 0.038 W/m⋅K). Heat is lost to the surroundings at 5° C by natural convection and radiation, with a combined natural convection and radiation heat transfer coefficient of 22 W/ m2⋅K.Taking the heat transfer coefficient inside the pipe to be 80 W/ m2⋅K.Determine the rate of heat loss from the steam per unit length of the pipe and Determine the temperature decrease between the inner pipe surface and the outer insulation surface.