Chapter 6 Viscous Flow in Ducts
P6.1 An engineer claims that flow of SAE 30W oil, at 20C, through a 5-cm-diameter smooth pipe at 1 million N/h, is laminar. Do you agree? A million newtons is a lot, so this sounds like an awfully high flow rate.
Solution:
Chapter 1 Introduction
1.1 A gas at 20C may be rarefied if it contains less than 1012 molecules per mm3. If Avogadros number is 6.023E23 molecules per mole, what air pressure does this represent? Solution: The mass of one molecule of air may be computed a
Chapter 7 Flow Past Immersed Bodies
P7.1 An ideal gas, at 20C and 1 atm, flows at 12 m/s past a thin flat plate. At a position 60 cm downstream of the leading edge, the boundary layer thickness is 5 mm. Which of the 13 gases in Table A.4 is this likely to
Chapter 11 Turbomachinery
11.1 Describe the geometry and operation of a human peristaltic PDP which is cherished by every romantic person on earth. How do the two ventricles differ? Solution: Clearly we are speaking of the human heart, driven periodically
Chapter 10 Open Channel Flow
10.1 The formula for shallow-water wave propagation speed, Eq. (10.9) or (10.10), is independent of the physical properties of the liquid, i.e., density, viscosity, or surface tension. Does this mean that waves propagate at th
Chapter 8 Potential Flow and Computational Fluid Dynamics
8.1 Prove that the streamlines (r, ) in polar coordinates, from Eq. (8.10), are orthogonal to the potential lines (r, ). Solution: The streamline slope is represented by
dr r d
|streamline = vr
v
=
Chapter 5 Dimensional Analysis and Similarity
5.1 For axial flow through a circular tube, the Reynolds number for transition to turbulence is approximately 2300 [see Eq. (6.2)], based upon the diameter and average velocity. If d = 5 cm and the fluid is ke
Chapter 4 Differential Relations for a Fluid Particle
4.1 An idealized velocity field is given by the formula
V = 4txi 2t 2 yj + 4 xzk
Is this flow field steady or unsteady? Is it two- or three-dimensional? At the point (x, y, z) = (1, +1, 0), compute (a)
Chapter 9 Compressible Flow
9.1 An ideal gas flows adiabatically through a duct. At section 1, p1 = 140 kPa, T1 = 260C, and V1 = 75 m/s. Farther downstream, p2 = 30 kPa and T2 = 207C. Calculate V2 in m/s and s2 s1 in J/(kg K) if the gas is (a) air, k = 1.
Chapter 3 Integral Relations for a Control Volume
3.1 Discuss Newtons second law (the linear momentum relation) in these three forms:
F = ma F = d (mV) dt F = d V d dt system
Solution: These questions are just to get the students thinking about the basi