A 70-mm diameter hot solid rod is suspended in a room in which the air and walls are at 25°C., The surface temperature of the rod and its emissivity are 200°C and 0.8, respectively. The associated coefficient of convective heat transfer from the rod surface to the air is 15 W/m2.K. If the total heat loss from the surface area of the rod is estimated to be 947 W, what is the length of the rod?
Area of both sides of the rod can be neglected.
A 70-mm diameter hot solid rod is suspended in a room in which the air and walls are at 25°C
heat and mass transfer (20 points) Air at 25°C cools a 2170 cylindrical battery (with a diameter of 21 mm and a length of 70 mm) with a cross flow velocity of 6 m/s. a) Determine the average convective heat transfer coefficient. (b) If the battery's internal heat generation is 5W and its thermal conductivity is 0.6 w/m-k, the determine the battery surface temperature and the maximum temperature in battery (20 points) Air at 25°C cools a 2170 cylindrical battery...
(13) A brewery fermentation tank 12 m in diameter is situated in a room, which has a temperature of 15°C. The tank is constructed of 10-mm welded steel plate with 12-mm glass lining. The temperature at the inner surface of the glass lining is 50°C. Assume that the convective resistance offered by the air film on the outside of the tank equals the combined resistance of the glass and steel. The thermal conductivity of glass is 0.80 W/mK and that...
A 25-mm-diameter hot surface at is cooled by an air jet exiting a 5-mm-diameter round nozzle with a velocity of 35 m/s and temperature of 25. The nozzle exit is 25 mm from the hot surface. Determine the percentage change in average heat transfer coefficient at the hot surface if the air is replaced with carbon dioxide or helium. Use material properties from reputable tables. We were unable to transcribe this imageWe were unable to transcribe this imageWe were unable...
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)....
HELP MEEE An uninsulated steam pipe passes through a room where the temperatures of the air and its walls are 38 degrees. The outer diameter of the pipe is 90 mm, the temperature and spreading rate of its surface are 200 degrees and 0.8, respectively. Calculate the radiating power of the surface and the radiation to the surface. Since the heat transfer coefficient with natural convection from the surface to the air is 25 w/m^2.K, what is the heat loss...
Thin-walled aluminum tubes of diameter D = 10 mm are used in the condenser of an air conditioner. Under normal operating conditions, a convection coefficient of hi = 5000 W/m2 · K is associated with condensation on the inner surface of the tubes, while a coefficient of ho = 100 W/m2 · K is maintained by airflow over the tubes. a. What is the overall heat transfer coefficient if the tubes are unfinned? b. What is the overall heat transfer...
Problem 2 (10/30) - Steam at 180 C (saturated) enters a 10 cm diameter, 0.4 mm thick, 150 m long carbon steel pipe which is exposed to the elements. Air flows across the pipe at 10 m/sec. Air emperature is 20 C. Convective heat transfer of stem to the pipe is very high. Emissivity of the pipe is estimated at 0.8.Calculate the rate of heat transfer from the pipe. State any assumptions. Problem 2 (10/30) - Steam at 180 C...
A very long rod 5mm in diameter has one end maintained at 100℃. The Surface of the rod is exposed to ambient air at 25℃, with a convective heat transfer coefficient of 100 W/m2K. If the rod is constructed from pure copper, what is the heat loss from the rod?
A horizontal uninsulated steam pipe passes through a large room whose walls and ambient air are at 300 K. The pipe of 125-mm diameter has an emissivity of 0.85 and an outer surface temperature of 373 K. Calculate the rate of heat loss per unit length from the pipe. The answer should be close to 45.2 W/m Please show all work clearly
A long cylindrical rod of diameter 220 mm with thermal conductivity 0.5 W/m-K expe riences uniform volumetric heat generation of 25,000 W/m3. The rod is encapsulated by a circular sleeve having 7 W/m K. The outer surface of the sleeve is exposed to cross flow of air at 25°C with a convection coefficient of 25 W/m2-K. Find the temperature at the interface between the rod and sleeve, and on the outer surface. an outer diameter of 410 mm and thermal...