Determine the temperature at the base of the shaft (where it connects to the motor. A shaft from a motor housing can be treated as a fin. The diameter of the stainless-steel shaft (k = 15.1 W/m-K) is 25 mm and it is 25 cm long. The shaft removes 10 W of heat from the motor. The air temperature around the motor is 200C with a convection coefficient of 25 W/m2-K. The end of the shaft not connected to

Determine the temperature at the base of the shaft (where it connects to the motor. A shaft from a motor housing can be treated as a fin. The diameter of the stainless-steel shaft (k = 15.1 W/m-K) is 25 mm and it is 25 cm long. The shaft removes 10 W of heat from the motor. The air temperature around the motor is 200C with a convection coefficient of 25 W/m2-K. The end of the shaft not connected to

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...

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Question 4 The window of a room is made of 5 mm thick glass which has a thermal conductivity of 1.4 W/m-K. A heater is used to maintain the room temperature at 22 °C. Take the convection heat transfer coefficients on the outer surface of the window to be 12 W/m²-K. Take appropriate assumptions while solving this problem. (a) T₁-15°C TA -A=1m x 3m 3m², k=1.4 W/m-K I L=0.005m Figure Q2 ** -T₂=5°C Find the convection heat transfer coefficients on the inner surface of the window.
A thermometric well is placed in a pipe having diameter of 55 mm. Pipe wall temperature is 100°C and heat transfer coefficient inside the pipe is 300 W/m² K. Thickness of thermowell is 1.2 mm and its length is 50 mm. Thermal conductivity of thermowell material. Is 30 W/mK. If the temperature of the gas flowing through the pipe is recorded by thermometer as 200°C, determine the true temperature of gas. If the error in gas temperature is to be reduced by 80% by increasing the length of thermowell, determine the new length of thermowell. Draw a sketch of this thermowell. Take perimeter to area ratio for thermowell as 1/T (T= thickness).
Question 4 The window of a room is made of 5 mm thick glass which has a thermal conductivity of 1.4 W/m-K. A heater is used to maintain the room temperature at 22 °C. Take the convection heat transfer coefficients on the outer surface of the window to be 12 W/m²-K. Take appropriate assumptions while solving this problem. (a) T₁=15°C TA -A- 1m x 3m = 3m², k=1.4W/m-K -T₂=5°C L=0.005m Figure Q2 Determine the heater thermal load to maintain the room temperature?
Two long rods of the same diameter, one of brass(k= 85 W/mK) and the other of copper (k=375 W/mK) have one of their ends inserted in a furnace and the other ends exposed to the same atmosphere. At a distance of 105mm away from the furnace, the temperature of the brass rod is 120 C. Find the distance form the furnace in which the copper rod have the same temperature
Required Information The upper surface of a 85-cm-thick solid plate (k= 237 W/m-K) is being cooled by water with temperature of 20°C. The upper and lower surfaces ofthe solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given ask= 237 W/m K. f2 (T,1+T) = (60°C + 20°C)/2 = 40°C is kuid = 0.631 The thermal conductivity of water at the film temperature of T; W/m/K. Determine the water convection heat transfer coefficient. The water convection heat transfer coefficient is W/m2 -K.
A cubical tank of 2 m sides is constructed of special metal plate 12 mm and contains water at 75°C. The surrounding air temperature is 16°C. Calculate the overall heat transfer coefficient from water to air. Take the coefficient of thermal conductivity of the metal as 48 W/m-K, the coefficient of heat transfer of water is 2.5 kW/m2-K and the coefficient of heat transfer of the air is 16 W/m2-K.
Determine the heat flux for a furnace wall made of fire clay if the furnace wall thickness is 6’’ and the thermal conductivity of the furnace clay is 0.3 W/m-K. The furnace wall temperature can be taken to be same as furnace operating temperature which is 650°C, and temperature of the outer wall is 150°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 .
1/ The roof of an electrically heated home is 6 m long, 8 m wide, and 0.25 m thick, and is made of a flat layer of concrete whose thermal conductivity is k = 0.8 W/m.°C (Figure. 1-3). The temperatures of the inner and the outer surfaces of the roof one night are measured to be 15°C and 4°C, respectively, for a period of 10 hours. Determine the rate of heat loss through the roof at night
A steam pipe 50 mm diameter and 2.5 m long has been placed horizontally and exposed to still air at 25 degree Celsius. If the pipe wall temperature is 295 degree Celsius, determine the rate of heat loss. At the mean temperature difference of 160 degree Celsius, the thermo-physical properties of air are k =3.64 * 10 -2 W/m v =30.09 * 10 -6 m2/ P r =0.68 Β =1/160 + 273 = 2.31 * 10^-3/K
It is designed in such a way that the internal temperature of a commercial heat treatment furnace can reach up to 165 oC. All surfaces of the furnace consist of firebrick (10 cm), insulation material and sheet metal (3mm) from the inside out. Given that the outdoor temperature is 22 oC, the outer sheet will be allowed to go up to 35 oC, which is a temperature that will not be disturbed by hand contact. In this case, determine the insulation material thickness to be used. Insulation material thermal conductivity coefficient is 0.066 insulation W / m oC, 60 W / m oC for sheet metal and 115 W / m oC for firebrick. Indoor heat transfer coefficient will be accepted as 25 W / m2 oC and 12 W / m2 oC for outdoor environment.
google.com ube Maps Electrically heated draw batch furnaces are commonly used in the heat treatment industry. Consider a draw batch furnace front made of a 20-mm thick steel plate with a ther- mal conductivity of 25 W/m-K. The furnace is situated in a room with surrounding air temperature of 20°C and an aver- age convection heat transfer coefficient of 10 W/m2-K. If the inside surface of the furnace front is subjected to uniform heat flux of 5 kW/m² and the outer surface has an emissiv- ity of 0.30, determine the inside surface temperature of the furnace front. = 20°C Furnace fron 4, = 5 kW/m Air, 20 C h= 10 W/m K e = 0.30 kn25 W/m-K