Problem 7-30:Hot engine oil at 150°C is flowing in parallel over a flat plate at a velocity of 2 m/s. Surfacetemperature of the 0.5-m-long flat plate is constant at 50°C. Determine (a) the local convection heattransfer coefficient at 0.2 m from the leading edge and the average convection heat transfercoefficient, and (b) repeat part (a) using the Churchill and Ozoe (1973) relation.Problem 7-76:In a geothermal power plant, the used geothermal water at 80°C enters a 15-cm-diameter and 400-m-long uninsulated pipe at a rate of 8.5 kg/s and leaves at 70°C before being reinjected back to theground. Windy air at 15°C flows normal to the pipe. Disregarding radiation, determine the averagewind velocity in km/h.Problem 7-112:Air is to be heated by passing it over a bank of 3-m-long tubes inside which steam is condensing at100°C. Air approaches the tube bank in the normal direction at 20°C and 1 atm with a mean velocityof 5.2 m/s. The outer diameter of the tubes is 1.6 cm, and the tubes are staggered with longitudinaland transverse pitches of S₂ = ST=4 cm. There are 20 rows in the flow direction with 10 tubes ineach row. Determine (a) the rate of heat transfer, (b) the pressure drop across the tube bank, and (c)the rate of condensation of steam inside the tubes. Evaluate the air properties at an assumed meantemperature of 35°C and 1 atm. Is this a good assumption?Problem 7-113:Repeat Prob. 7-112 for in-line arrangement with S,= ST = 6 cm.

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Hot engine oil at 150°C is flowing in parallel over a flat plate at a velocity of 2 m/s. Surface temperature of the 0.5-m-long flat plate is constant at 50°C. Determine (a) the local convection heat transfer coefficient at 0.2 m from the leading edge and the average convection heat transfer coefficient, and (b) repeat part (a) using the Churchill and Ozoe (1973) relation.

Hot engine oil at 150°C is flowing in parallel over a flat plate at a velocity of 2 m/s. Surface temperature of the 0.5-m-long flat plate is constant at 50°C. Determine (a) the local convection heat transfer coefficient at 0.2 m from the leading edge and the average convection heat transfer coefficient, and (b) repeat part (a) using the Churchill and Ozoe (1973) relation.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

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Question

Problem 7-30:
Hot engine oil at 150°C is flowing in parallel over a flat plate at a velocity of 2 m/s. Surface
temperature of the 0.5-m-long flat plate is constant at 50°C. Determine (a) the local convection heat
transfer coefficient at 0.2 m from the leading edge and the average convection heat transfer
coefficient, and (b) repeat part (a) using the Churchill and Ozoe (1973) relation.
Problem 7-76:
In a geothermal power plant, the used geothermal water at 80°C enters a 15-cm-diameter and 400-m-
long uninsulated pipe at a rate of 8.5 kg/s and leaves at 70°C before being reinjected back to the
ground. Windy air at 15°C flows normal to the pipe. Disregarding radiation, determine the average
wind velocity in km/h.
Problem 7-112:
Air is to be heated by passing it over a bank of 3-m-long tubes inside which steam is condensing at
100°C. Air approaches the tube bank in the normal direction at 20°C and 1 atm with a mean velocity
of 5.2 m/s. The outer diameter of the tubes is 1.6 cm, and the tubes are staggered with longitudinal
and transverse pitches of S₂ = ST=4 cm. There are 20 rows in the flow direction with 10 tubes in
each row. Determine (a) the rate of heat transfer, (b) the pressure drop across the tube bank, and (c)
the rate of condensation of steam inside the tubes. Evaluate the air properties at an assumed mean
temperature of 35°C and 1 atm. Is this a good assumption?
Problem 7-113:
Repeat Prob. 7-112 for in-line arrangement with S,= ST = 6 cm.

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