1 1. Consider two very large parallel plates with diffuse gray surfaces (i.e., non-black surface) ....
4.16 Two large diffuse gray parallel plates, separated by a small distance, have surface temperature of 400 K and 300 K. IF the emissivities of the surfaces are 0.8 and the Stefan-Boltzmann constant is 5.67 x 10-8 W/m3K4, the net radiation heat exchange rate in kW/m2 between the two plates is (a) 0.66 (c) 0.99 (b) 0.79 (d) 3.96
3. Two large, diffuse, grey, parallel surfaces are separated by a small distance. If the surface emissivities of each plate is 0.7, what emissivity should a thin radiation shield have to reduce the radiation heat transfer rate between the two surfaces by a factor of 20? 3. Two large, diffuse, grey, parallel surfaces are separated by a small distance. If the surface emissivities of each plate is 0.7, what emissivity should a thin radiation shield have to reduce the radiation...
it’s heat transfer class.. quick answer and clear steps please 3. For a four-surface system, all surfaces are diffuse and gray. All surfaces have the same size of square 2 m2 and the emissivities are 0.7,0.5, 0.7 and 0.8 for surface 1-4, respectively. The temperature of these surfaces are 500K, 400K, 500K and 700K for surface 1-4 respectively. (30+10 PTS) (a) Build the entire resistance system. (b) What are the view factors between surface 1 to 2 and 2 to...
Two facing surfaces of two large parallel conducting plates separated by 12.0 cm have uniform surface charge densities such that are equal in magnitude but opposite in sign. The difference in potential between the plates is 490 V. (a) Is the positive or the negative plate at the higher potential? O the pusitive plale O the negative plate (b) What is the magnitude of the electric field between the plates? kV/m (c) An electron is released from rest next to...
Two facing surfaces of two large parallel conducting plates separated by 8.5 cm have uniform surface charge densities such that are equal in magnitude but opposite in sign. The difference in potential between the plates is 440 V (a) Is the positive or the negative plate at the higher potential? the positive plate the negative plate (b) What is the magnitude of the electric field between the plates? 5.17 kV/mm (c) An electron is released from rest next to the...
Two very large parallel plates with a uniform surface charge density are seperated by a distance d. a) Show that the electric field between the plates b) Using solid lines, draw the electric field. c) If an electron were to enter between the plates with a velocity along the +x direction, draw the path of its motion.
Homework 7 heat transfer 2018-20 1) A horizontal tube of 12.5-mm dimeter with an outer srface temperature of 240°C is placed in a room with an air temperature of 20°C. Estimate the heat transfer rate per unit length of the tube due to free convection. 2) Air at -10°C flows at 10 m/s over the roof plate of two 5m length rooms whose air is at Too-200C. The roof plate is 0.20-m thick concrete (k = 0.6 w/ m. K)....
Question 1 2 points Save Answer Two very large parallel plates shown in the figure maintained at uniform tomperatures. Determine the netrade of radiation heat transfer between the two plates (in Watt) Assume Th=763 K and p = 0.7 T, 400K E -0.9
Two very large parallel sheets are 5.00 cm apart. Sheet A carries a uniform surface charge density of -6.80 μC/m2 , and sheet B, which is to the right of A, carries a uniform charge density of +12.1 μC/m2 . Assume that the sheets are large enough to be treated as infinite. PART C: Part E: Any help accounting for both of these questions would be very appreciated, please include the work and explanations to go along with them. Problem...
Two large parallel plates of smooth sheet iron are separated by a vacuum. Coulson and Richardson (1999) reports that the emissivity of smooth sheet iron is in the range of 0.55 – 0.60 (OK to assume grey bodies). The temperatures of the sheets are 300 and 100°F. If the two surfaces are at the lower end of emissivity (0.55), what is the net radiation heat flux from the hotter surface to the cooler one, Q12/A ([=] W/m2)? Repeat part (a)...