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Assignment Chapter 6 Sol

Course

Heat Transfer (ME 531)

15 Documents
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Academic year: 2019/2020

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ME-531 HEAT TRANSFER – I 7 th of July 2020

Assignment

Chapter 06

Instructor: Student:

Dr. Ahmad Abbas Ahsan Tanveer

AP FME, GIKI, Swabi. ME-

Questions

6 – 11 The upper surface of a 50-cm-thick solid plate (k=237 W/m· K) is being cooled by water with temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures of 60°C and 120°C, respectively. Determine the water convection heat transfer coefficient and the water temperature gradient at the upper plate surface.

6 – 17 A metal plate is being cooled by air (kfluid=0 W/m· K) at the upper surface while the lower surface is subjected to a uniform heat flux of 1000 W/m2. Determine the temperature gradient in the air at the upper surface of the metal plate.

6 – 18 The top surface of a metal plate (kplate=237 W/m· K) is being cooled by air (kair=0 W/m· K) while the bottom surface is exposed to a hot steam at 100°C with a convection heat transfer coefficient of 30 W/m2· K. If the bottom surface temperature of the plate is 80°C, determine the temperature gradient in the air and the temperature gradient in the plate at the top surface of the plate.

6 – 38 Consider fluid flow over a surface with a velocity profile given as

Determine the shear stress at the wall surface, if the fluid is (a) air at 1 atm and (b) liquid water, both at 20°C. Also calculate the wall shear stress ratio for the two fluids and interpret the result.

6 – 45 Consider fluid flowing with a free stream velocity of 5 m/s over a flat plate, where the critical Reynolds number is 5x 105. Determine the distance from the leading edge at which the transition from

laminar to turbulent flow occurs for air (at 1 atm), liquid water, methanol, and engine oil, all at 20°C, and mercury at 25°C.

6 – 58 Consider a 5-cm-diameter shaft rotating at 4000 rpm in a 25-cm-long bearing with a clearance of 0. mm. Determine the power required to rotate the shaft if the fluid in the gap is (a) air, (b) water, and (c) oil at 40°C and 1 atm.

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Assignment Chapter 6 Sol

Course: Heat Transfer (ME 531)

15 Documents
Students shared 15 documents in this course
Was this document helpful?
ME-531 HEAT TRANSFER I 7th of July 2020
Assignment
Chapter 06
Instructor: Student:
Dr. Ahmad Abbas Ahsan Tanveer
AP FME, GIKI, Swabi. ME-1959
Questions
611 The upper surface of a 50-cm-thick solid plate (k=237 W/m·K) is being cooled by water with
temperature of 20°C. The upper and lower surfaces of the solid plate maintained at constant temperatures
of 60°C and 120°C, respectively. Determine the water convection heat transfer coefficient and the water
temperature gradient at the upper plate surface.
617 A metal plate is being cooled by air (kfluid=0.259 W/m·K) at the upper surface while the lower
surface is subjected to a uniform heat flux of 1000 W/m2. Determine the temperature gradient in the air at
the upper surface of the metal plate.
618 The top surface of a metal plate (kplate=237 W/m·K) is being cooled by air (kair=0.243 W/m·K)
while the bottom surface is exposed to a hot steam at 100°C with a convection heat transfer coefficient of
30 W/m2·K. If the bottom surface temperature of the plate is 80°C, determine the temperature gradient in
the air and the temperature gradient in the plate at the top surface of the plate.
638 Consider fluid flow over a surface with a velocity profile given as
Determine the shear stress at the wall surface, if the fluid is (a) air at 1 atm and (b) liquid water, both at
20°C. Also calculate the wall shear stress ratio for the two fluids and interpret the result.
645 Consider fluid flowing with a free stream velocity of 5 m/s over a flat plate, where the critical
Reynolds number is 5x105. Determine the distance from the leading edge at which the transition from