The lower surface of a horizontal aluminum plate 5 in. by 7 in. is heated by...
The lower surface of a horizontal aluminum plate 5 in. by 7 in. is heated by an electric resistance heater that supplies 10 W. The upper surface is cooled by free convection and radiation. The convective transfer coefficient is 1.2 Btu/hr ft2 °F and the air temperature is 70 °F. Surrounding room surfaces are also at 70 °F. Find the surface temperature of the aluminum if it is
a) clean and shiny with ε=0.05
b) painted with ε=0.9
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The lower surface of a horizontal aluminum plate 5 in. by 7 in.
is heated by...
Surface 1 is long heated plate running through a large room. This plate is 0.3 m...
Surface 1 is long heated plate running through a large room. This plate is 0.3 m high, &q=0.8 for its surface, and its surface temperature is T = 500 K. Surface 2 is a long cooled plate that is parallel to the heated plate and positioned 0.4 m away from the heated plate. This plate is also 0.3 m high, &, = 0.8 for its surface, and its surface temperature is T, = 250 K. Surface 3 is the room...
The solar radiation incident on the outside surface of an aluminum shading device is 1300 W/m2...
The solar radiation incident on the outside surface of an aluminum shading device is 1300 W/m2 . Aluminum absorbs 10% of the incident solar energy, and dissipates it by convection from the back surface and by combined convection and radiation from the outside surface. The convection heat transfer coefficient is 10 W/m2 ·K for both surfaces, and the ambient/surrounding temperature can be taken 20 °C for both convection and radiation. Assuming that the aluminum shade has a uniform temperature, determine...
Steel racking with mass 100 lb and surface area 50 ft2 is used to carry products into a batch dry...
Steel racking with mass 100 lb and surface area 50 ft2 is used to carry products into a batch drying oven at 500 F. The combustion efficiency of the oven is 70%. The specific heat of steel is 0.12 Btu/lb-F, and the convection coefficient is 2 Btu/hr-ft2-F. If the racking enters the oven at room temperature of 70 F and the drying process takes 0.25 hours, calculate the exit temperature of the racking, and the heat and fuel energy loss...
A mild steel plate that is 1.4 in. thick and cross section 2 ft. x 2...
A mild steel plate that is 1.4 in. thick and cross section 2 ft. x 2 ft. is placed horizontally in the sun. The top surface of the plate is exposed to air at 90°F and the lower surface of the plate is exposed to air with a convective heat transfer coefficient of 3 Btu/h ftF. If the incident solar radiation on the plate is about 400 Btu/h, and the convective heat-transfer coefficient between the top surface and the surrounding...
An aluminum plate with a thickness of L=5 mm is mounted in a horizontal position, and...
An aluminum plate with a thickness of L=5 mm is mounted in a horizontal position, and its bottom surface is well insulated. A special, thin coating (with emissivity and solar absorptivity of 0.25) is applied to the top surface. The density ρ and specific heat c of aluminum are known to be 2700 kg/m3 and 900 J/kg · K, respectively. Consider conditions for which the plate is initially at a temperature of ??????=25 °C and its top surface is suddenly...
1 answer & continue > The upper surface of a 60-cm-thick solid plate (k = 237...
1 answer & continue > The upper surface of a 60-cm-thick solid plate (k = 237 W/m-K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k = 237 W/mK. The thermal conductivity of water at the film temperature of T; = (1,1770) =(60°C + 20°C)/2 = 40°C is kfluid =...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k= 237 W/m.K. (T1+T) The thermal conductivity of water at the film temperature of Tf =(60°C + 20°C)/2 = 40°C is kfluid = 0.631 W/m.K. = 2 1. value: 3.00...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k = 237 W/ mK. (T..+) The thermal conductivity of water at the film temperature of T, = =(60°C + 20°C)/2 = 40°C is kfluid = 0.631 W/mK. 1. value...
A 5 m long x 1m wide horizontal plate is heated on top and insulated on...
A 5 m long x 1m wide horizontal plate is heated on top and insulated on the bottom. The plate is maintained at 200 C. The air and walls of the room are maintaine d at 25°C. Determine the heat transfer by nature convection and radiation heat transfer. Assume an emissivity of 0.8.
please show me how I can finds the answers of these two examples Example 1: Design of a Solar Heater (Black bodies: no convection) A square flat plate collector is exposed to solar radiation from...
please show me how I can finds the answers of these two
examples
Example 1: Design of a Solar Heater (Black bodies: no convection) A square flat plate collector is exposed to solar radiation from both the sides. The exposed surface of the plate has an absorptivity of 1.0 for solar radiation. On a clear summer day on the earth's surface the solar radiation flux is approximately 1140 W/m2 and the surrounding air temperature is 25oC. Determine the surface temperature?...
Surface 1 is long heated plate running through a large room. This plate is 0.3 m high, &q=0.8 for its surface, and its surface temperature is T = 500 K. Surface 2 is a long cooled plate that is parallel to the heated plate and positioned 0.4 m away from the heated plate. This plate is also 0.3 m high, &, = 0.8 for its surface, and its surface temperature is T, = 250 K. Surface 3 is the room...
A mild steel plate that is 1.4 in. thick and cross section 2 ft. x 2 ft. is placed horizontally in the sun. The top surface of the plate is exposed to air at 90°F and the lower surface of the plate is exposed to air with a convective heat transfer coefficient of 3 Btu/h ftF. If the incident solar radiation on the plate is about 400 Btu/h, and the convective heat-transfer coefficient between the top surface and the surrounding...
1 answer & continue > The upper surface of a 60-cm-thick solid plate (k = 237 W/m-K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k = 237 W/mK. The thermal conductivity of water at the film temperature of T; = (1,1770) =(60°C + 20°C)/2 = 40°C is kfluid =...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k= 237 W/m.K. (T1+T) The thermal conductivity of water at the film temperature of Tf =(60°C + 20°C)/2 = 40°C is kfluid = 0.631 W/m.K. = 2 1. value: 3.00...
The upper surface of a 60-cm-thick solid plate (k = 237 W/m.K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Given: The thermal conductivity of the solid plate is given as k = 237 W/ mK. (T..+) The thermal conductivity of water at the film temperature of T, = =(60°C + 20°C)/2 = 40°C is kfluid = 0.631 W/mK. 1. value...
A 5 m long x 1m wide horizontal plate is heated on top and insulated on the bottom. The plate is maintained at 200 C. The air and walls of the room are maintaine d at 25°C. Determine the heat transfer by nature convection and radiation heat transfer. Assume an emissivity of 0.8.
please show me how I can finds the answers of these two
examples
Example 1: Design of a Solar Heater (Black bodies: no convection) A square flat plate collector is exposed to solar radiation from both the sides. The exposed surface of the plate has an absorptivity of 1.0 for solar radiation. On a clear summer day on the earth's surface the solar radiation flux is approximately 1140 W/m2 and the surrounding air temperature is 25oC. Determine the surface temperature?...
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