2) PROBLEM 2; Water is flowing in a horizontal 2 -in. schedule 80 steel pipe at an average temperature of 37.8C and a velocity of 3m/s. It is being heated by condensing steam at 110C on the outside of the pipe wall. The steam-side coefficient has been estimated as h=10000W/m2.K. The length of the pipe is 0.5m. a) Calculate the convective coefficient h for water inside the pipe. b) Calculate the overall coefficient U based on the inside surface area. c) Calculate the heat-transfer rate for this pipe with water at an average temperature of 37.8C. Hint: Please note that one trial solution is enough for this trial and error problem. Hot air at atmospheric pressure and 80C enters an 8m-long uninsulated square duct of cross section 0.2m0.2m that passes through the attic of a house at a rate of 0.15m3/s. The outside surface of the duct is observed to be nearly isothermal at 60C. The air is leaving the duct at a temperature of 71C. Determine the heat loss from the duct to the attic space. Hint: The temperature of the inside surface of the duct will be assumed isothermal, and equal to the outside surface of the duct. Page 1 of 1 4.51 Heating Air by Condensing Stea m. Air is flowing through a tube having an inside diameter of 38.1mm at a velocity of 6.71m/s, average temperature of 449.9K, and pressure of 138kPa. The inside wall temperature is held constant at 204.4C(477.6K ) by steam condensing outside the tube wall. Calculate the hent-transfer coefficient for a long tube and the heat-trnnsfer flux. 2) PROBLEM 2; Water is flowing in a horizontal 2 -in. schedule 80 steel pipe at an average temperature of 37.8C and a velocity of 3m/s. It is being heated by condensing steam at 110C on the outside of the pipe wall. The steam-side coefficient has been estimated as h=10000W/m2.K. The length of the pipe is 0.5m. a) Calculate the convective coefficient h for water inside the pipe. b) Calculate the overall coefficient U based on the inside surface area. c) Calculate the heat-transfer rate for this pipe with water at an average temperature of 37.8C. Hint: Please note that one trial solution is enough for this trial and error problem. Hot air at atmospheric pressure and 80C enters an 8m-long uninsulated square duct of cross section 0.2m0.2m that passes through the attic of a house at a rate of 0.15m3/s. The outside surface of the duct is observed to be nearly isothermal at 60C. The air is leaving the duct at a temperature of 71C. Determine the heat loss from the duct to the attic space. Hint: The temperature of the inside surface of the duct will be assumed isothermal, and equal to the outside surface of the duct. Page 1 of 1 4.51 Heating Air by Condensing Stea m. Air is flowing through a tube having an inside diameter of 38.1mm at a velocity of 6.71m/s, average temperature of 449.9K, and pressure of 138kPa. The inside wall temperature is held constant at 204.4C(477.6K ) by steam condensing outside the tube wall. Calculate the hent-transfer coefficient for a long tube and the heat-trnnsfer flux