Determine the convection heat transfer coefficient (in W/m2-K) for air flowing at a velocity of 8m/s in a 10-cm diameter and 10-m long tube. Air enters the tube at 30°C and leaves at 20°C, i.e.air is cooled. Take the property of air at 1 atm and assume flow to be fully developed.For air at 1 atm:Temperaturek, W/m-Kv, m?/sPr15°C0.024761.470x10-50.732320°C0.025141.516x10-50.730925°C0.025511.562x10-50.7296Hint: When the fluid temperature changes, we use its properties at mean temperature, unless otherwisespecified.Round your answer to 2 decimal places.Add vour answer

Answered: Image /qna-images/answer/826b788d-ba69-43e1-a685-63d1079d6541.jpg

Determine the convection heat transfer coefficient (in W/m2-K) for air flowing at a velocity of 8 m/s in a 10-cm diameter and 10-m long tube. Air enters the tube at 30°C and leaves at 20°C, i.e. air is cooled. Take the property of air at 1 atm and assume flow to be fully developed.

Determine the convection heat transfer coefficient (in W/m2-K) for air flowing at a velocity of 8 m/s in a 10-cm diameter and 10-m long tube. Air enters the tube at 30°C and leaves at 20°C, i.e. air is cooled. Take the property of air at 1 atm and assume flow to be fully developed.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Consider a 60-cm-long journal bearing that is lubricated with oil whose viscosity is 0.1 kg/m-s at 20°C at the beginning of operation and 0.008 kg/m-s at the anticipated steady operating temperature of 80'C. The diameter of the shaft is 8 cm, and the average gap between the shaft and the journal is 0.08 cm. Determine the torque needed to overcome the bearing friction initially and during steady operation when the shaft is rotated at 1500 rpm. The torque required to overcome the bearing friction is The torque required during steady operation is N-m. N-m.
Consider a hot baked potato. Will the potato cool faster or slower when we blow the warm air com ing from our lungs on it instead of letting it cool naturally in the cooler room air? Briefly explain your answer.
7-115 Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.8-m-long tubes inside which the refrigerant is evaporating at –20°C. Air approaches the tube bank in the normal direction at 0°C and 1 atm with a mean velocity of 5 m/s. The tubes are arranged in-line with longitudinal and transverse pitches of SL = ST = 1.5 cm. There are 25 rows in the %D flow direction with 15 tubes in each row. Determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. Evaluate the air properties at an assumed mean temperature of -5°C and 1 atm. Is this a good assumption? 0.8 m Air 0°C 1 atm ST = 1.5 cm 5 m/s 0.8 cm 1.5 cm/ S, = Refrigerant, –20°C FIGURE P7–115
How is volume flow rate different than velocity? What happens to volume flow rate in areas where fluid pressure is high?
Liquid mercury is flowing at 0.9kg/s through a 5-cm diameter tube with inlet and outlet mean temperatures of 100°C and 200°C, respectively. The tube surface temperature is maintained constant at 250°C. Determine the tube length using the Dittus-Boelter equation, in m. ______ m
A 65 kg beef carcass (k-0.47 w/mk and a-0.13 x10-6 m/s) initially at a uniform temperature of 37 "C is to be cooled by refrigerated air at -10 oC flowing at a velocity of 1.2 ms. The average heat transfer coefficient between the carcass and the air is 22 W/m²K. Treating the carcass as a cylinder of diameter 24 cm and the height 1.4 m and disregarding heat transfer from the base and top surfaces, Determine how long it will take for the centre temperature of the carcass to drop to 4 °C b. Also, determine if any part of the carcass will freeze during this process Hava- air -10 °C 12m/s Sider E Beef JTC
Combustion gases passing through a 5-cm-internal-diameter circular tube are used to vaporize waste water at atmospheric pressure. Hot gases enter the tube at 225 kPa and 250oC at a mean velocity of 2.5 m/s, and leave at 150o If the average heat transfer coefficient is 150 W/m2K and the inner surface temperature of the tube is 110oC, determine (a) the tube length and (b) the rate of evaporation of water.
Liquid sodium is to be heated from 500 K to 600 K by passing it at a flow rate of 5.0 kg/s through a 5-cm-ID tube whose surface is maintained at 620 K. What length of tube is required?
6-34 Liquid ammonia at 10°C and 1 atm flows across a horizontal cylinder at a velocity of 5 m/s. The cylinder has a diameter of 2.5 cm and length of 125 cm and is maintained at a temperature of 30°C. Calculate the heat lost by the cylinder. 6-65 Water flows over a 3-mm-diameter sphere at 5 m/s. The free- stream temperature is 38°C, and the sphere is maintained at 93°C. Calculate the heat-transfer rate. 6-95 A tube bank consists of a square array of 144 tubes arranged in an in-line position. The tubes have a diameter of 1.5 cm and length of 1.0 m; the center-to-center tube spacing is 2.0 cm. If the surface temperature of the tubes is maintained at 350 K and air enters the tube bank at 1 atm, 300 K, and u∞ = 6 m/s, calculate the total heat lost by the tubes.
Fluid with a density of 602 kg/m³ flows inside a 3.3 cm diameter tube at a velocity of 1.7 m/s. The fluid enters the tube at 85°C and exits at 33°C. At the average bulk temperature, the thermal conductivity is 0.50 W/m K, the absolute viscosity is 6.26 x 104 kg/m s and the Prandtl number is 6.65. Using the Dittus-Boelter correlation Nu-0.023Re0.8p where n = 0.4 for heating: n = 0.3 for cooling What is the convection heat transfer coefficient? Express your answer in W/m² K?
0.809 and 0.795 3-176 The overall heat transfer coefficient of a wan s determined to be U= 0,425 W/m-°C under the condi- tions of still air inside and winds of 12 km/h outside. What will the U-factor be when the wind velocity outside is doubled? Answer: 0.428 W/m-°C ransler olls of