AOE 4064

The flashcards below were created by user kylecaro on FreezingBlue Flashcards.

  1. The table lists values of
    Reynolds number for various animals in motion.

    For which cases is the inertia of
    the fluid important?

    a. whale @ 10 m/s: Re=300,000,000

    b. flying duck @ 20 m/s:

    c. dragonfly @ 7 m/s: Re=30,000

    d. larva @ 1 mm/s: Re=0.3

    e. bacterium @ 0.01 mm/s:
  2. A radio antenna on a car consists
    of a circular cylinder 1/4 inch in diameter

    and 4 feet long. The bending
    moment at the base of the antenna when the

    car is going 55 mph is about:
  3. The wind in a storm reaches a
    speed of 65 mph blowing perpendicular

    against a 3 ft X 6 ft window in
    the side of a high-rise building with

    dimensions much larger than the
    window. 65 mph is the wind speed at the

    height of the window. The force
    on the window is about:
  4. A 1:10 scale model of a whale is
    to be tested in a towing tank or water

    tunnel at a speed such that the
    Reynolds number in the test matches that in

    the real situation. In that case,
    the drag force for the model test and the real

    situation can be expected to
    compare as
  5. A fish whose length is twice its
    maximum diameter resembles a spheroid

    and has a specific gravity of
    1.2. If added mass is ignored, the percentage

    error in a calculation of its
    acceleration from rest would be about:
  6. A 2 cm. diameter cylinder is in a
    4 m/s air stream. The frequency of vortex

    shedding would be expected to be
  7. The boundary layer thickness at
    the end of a 4.0 m. long plate in an air

    stream of 5.0 m/s would be about:
  8. A chemical called NTA that is
    frequently used in detergents leaks into a

    small lake with a surface area of
    0.2 square km. and a maximum depth of

    9.0 m. The vertical profile of
    NTA concentration, C in micromoles per cubic

    meter vs. z in meters, is
    measured as listed below:

    z: 1.0, 2.0, 3.0, 4.0, 5.0, 6.0,
    7.0, 8.0, 9.0, 10.0

    C: 5.2, 5.1, 4.9, 3.2, 2.9, 2.6,
    2.4, 2.1, 1.8

    If the vertical turbulent
    diffusion coefficient is 1.2 cm**2/s, the vertical flux

    of NTA in
    moles/m**2/s at a depth of 7.0 m. is about:
  9. At high Reynolds number, the
    power needed to overcome the drag of a body

    moving at a speed, U, varies as U
    to the power n, where n equals about:
  10. A fluid has a viscosity of 0.001
    lb-sec/ft**2 and a specific gravity of

    0.913. At a location on a solid
    surface where the edge velocity is 45 in/sec,

    there is a laminar boundary layer
    3.0 inches thick. Assuming a linear

    velocity profile, the shear in
    the middle of the boundary layer is:
  11. True/False

    It is possible for the drag on a
    tall, slender tree trunk to be the same in a 2.0

    mph wind as in a 4.0 mph wind.
  12. True/False

    There is an important effect of
    altitude on the drag of small pollen particles

    under conditions where the
    temperature change with altitude is negligible.
  13. True/False

    The Reynolds number for a flowing
    glacier is large
  14. True/False

    Useful locations for wind energy
    generation occur uniformly across the

  15. True/False

    Wind-generated waves and Tsunamis
    move at very different speeds
  16. True/False

    The Froude number is proportional
    to the ratio of viscous forces to gravity

  17. True/False

    Internal waves do not occur in
    the ocean.
  18. True/False

    One can calculate the vorticity
    in a boundary layer without knowing if the

    flow is laminar or turbulent.
  19. True/False

    Murray's Law is an early example
    of multidisciplinary design optimization.
  20. True/False

    The pressure drop for turbulent
    flows in very rough pipes does not vary

    with Reynolds number
  21. True/False

    The Stokes Radius refers to the
    distance of detection of surface insects by

  22. True/False

    The production of thrust by
    creatures in the Low Reynolds number regime

    does not depend upon circulation.
  23. True/False

    The wingbeat frequency of insects
    decreases with insect size.
  24. True/False

    The "clap and
    fling" mechanism is important to understanding insect flight.
  25. True/False

    The added mass coefficient varies
    strongly with body shape.
  26. True/False

    Some creatures derive a
    significant proportion of their total lift from their

  27. True/False

    The drag of creatures in the low
    Reynolds number regime varies as their

    speed squared.
  28. True/False

    Atmospheric boundary layer flows
    can be studied in conventional wind

    tunnels without substantial
  29. True/False

    Fick's Law is used to model mass
    transport and diffusion in nature.
  30. True/False

    Temperature effects can be
    neglected in the modeling of chemical and

    biological reactions in nature.
Card Set:
AOE 4064
2012-01-13 20:23:09

Previous exam questions
Show Answers: