Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
8th Edition
ISBN: 9781305387102
Author: Kreith, Frank; Manglik, Raj M.
Publisher: Cengage Learning
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Chapter 5, Problem 5.6P
A fluid flows at 5
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Cooling water for a power plant is stored in a pond 900 m in length and
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The velocity distribution in a fully developed laminar pipe flow is given by where UCL is the velocity at the centerline, and R is the pipe radius. The fluid density is ρ, and its viscosity is µ. (a) Find the average velocity . (b) Write down the Reynolds number Re based on average velocity and pipe diameter. At what approximate value of this Reynolds number would you expect the flow to become turbulent? Why is this value only approximate? (c) Assume that the stress/strain rate relationship for the fluid is Newtonian. Find the wall shear stress τw in terms of µ, R and UCL. Express the local skin friction coeffient Cf in terms of the Reynolds number Re.
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Large-scale turbulentmotion is roughly dependent of viscosity. In other words, at high Reynolds numbers, viscous
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forces, which contribute to flow stability, are significant compared to inertial forces that contribute to flow instability.
flatter than that in turbulent flow
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(D) Flow inside an eddy is turbulent because of its large size.
E) Average fluid velocity of Newtonian fluids in laminar flow inside a circular pipe is twice the maximum fluid velocity
Chapter 5 Solutions
Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)
Ch. 5 - Evaluate the Reynolds number for flow over a tube...Ch. 5 - 5.2 Evaluate the Prandtl number from the following...Ch. 5 - Evaluate the Nusselt number for flow over a sphere...Ch. 5 - 5.4 Evaluate the Stanton number for flow over a...Ch. 5 - Evaluate the dimensionless groups hcD/k,UD/, and...Ch. 5 - 5.6 A fluid flows at 5 over a wide, flat plate 15...Ch. 5 - 5.7 The average Reynolds number for air passing in...Ch. 5 - Prob. 5.8PCh. 5 - When a sphere falls freely through a homogeneous...Ch. 5 - 5.10 Experiments have been performed on the...
Ch. 5 - 5.13 The torque due to the frictional resistance...Ch. 5 - The drag on an airplane wing in flight is known to...Ch. 5 - 5.19 Suppose that the graph below shows measured...Ch. 5 - Engine oil at 100C flows over and parallel to a...Ch. 5 - For flow over a slightly curved isothermal...Ch. 5 - Air at 20C flows at 1 m/s between two parallel...Ch. 5 - Air at 1000C flows at an inlet velocity of 2 m/s...Ch. 5 -
5.43 A refrigeration truck is traveling at 130...Ch. 5 - The air-conditioning system in a Chevrolet van for...Ch. 5 - Determine the rate of heat loss from the wall of a...
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