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 5.8P
To determine
Towing speed for the model ship.
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An underwater device which is 2m long is to be moved at 4 m/sec. If a geometrically
similar model 40 cm long is tested in a variable pressure wind tunnel at a speed of 60
m/sec with the following information,
Poir at Standard atmospheric pressure = 1.18kg/m³
Pwater = 998kg/m3
Hair = 1.80 x 10-5 Pa-s at local atmospheric pressure and
Hwater = 1 × 10-3 Pa-s then the pressure of the air in the model used
times local atmospheric pressure
is
A student team is to design a submarine for a design competition. The overall
length of the prototype submarine is 4.85 m. The prototype submarine is
expected to moves through freshwater in the lake at 0.440 m/s. The student team
builds a one-fifth scale model to test in their university's wind tunnel. Calculate
the wind tunnel air speed in order to achieve similarity with the prototype
submarine. For water at T= 15 °C and atmospheric pressure, the density is p =
999.1 kg/m³ and the dynamic viscosity is µ = 1.138 x 10³ kg/m-s. For air in the
wind tunnel at T= 25 °C and atmospheric pressure, the density is p= 1.184 kg/m³
and the dynamic viscosity is µ = 1.849 x 10-$ kg/m's.
An airplane wing, with chord length of 1.5 m and span of 9 m, is designed to move through
standard air (v= 1.51x105 m²/s) at a speed of 7.5 m/s. A 1/10-scale model of this wing is to
be tested in a water tunnel (v= 1.00×106 m²/s). If viscous effects govern, what speed is
necessary in the water tunnel to achieve dynamic similarity?
a.11.33 m/s
b.4.97 m/s
c.1.51 m/s
d.2.98 m/s
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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