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

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:
Re=300,000
c. dragonfly @ 7 m/s: Re=30,000
d. larva @ 1 mm/s: Re=0.3
e. bacterium @ 0.01 mm/s:
Re=0.00003

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:

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 highrise 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:

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

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:

A 2 cm. diameter cylinder is in a
4 m/s air stream. The frequency of vortex
shedding would be expected to be
about:

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:

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:

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:

A fluid has a viscosity of 0.001
lbsec/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:

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.

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.

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

True/False
Useful locations for wind energy
generation occur uniformly across the
USA.

True/False
Windgenerated waves and Tsunamis
move at very different speeds

True/False
The Froude number is proportional
to the ratio of viscous forces to gravity
forces.

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

True/False
One can calculate the vorticity
in a boundary layer without knowing if the
flow is laminar or turbulent.

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

True/False
The pressure drop for turbulent
flows in very rough pipes does not vary
with Reynolds number

True/False
The Stokes Radius refers to the
distance of detection of surface insects by
fish.

True/False
The production of thrust by
creatures in the Low Reynolds number regime
does not depend upon circulation.

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

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

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

True/False
Some creatures derive a
significant proportion of their total lift from their
body.

True/False
The drag of creatures in the low
Reynolds number regime varies as their
speed squared.

True/False
Atmospheric boundary layer flows
can be studied in conventional wind
tunnels without substantial
modifications.

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

True/False
Temperature effects can be
neglected in the modeling of chemical and
biological reactions in nature.

