make "explain the fluid mechanics of that" website (students email ...

sisterpurpleMechanics

Oct 24, 2013 (3 years and 8 months ago)

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E
mail Prof. Sanders (
ssanders@engr.wisc.edu
) with your curiosities for him to post here.


fluid mechanics curiosities:


1.

You attempt to quickly close the door of a room and notice it is difficult to close it
fu
lly.
What roles does fluid mechanics play in this problem? What are the
dependencies on:



how tight the clearance between the door and the jamb is?



the size of the room?



whether the window in the room is open or closed?



how far away is the open win
dow in

the room?


2.

energy:



h
ow much power should we be able to extract from a field of wind
turbines on an average windy day?

how many blades and what pitch is
optimum?



h
ow much energy
of a fuel’s energy content
is expended in transporting
that fuel
through pipe
lines or by vehicles
(consider gasoline, methane,
hydrogen)?


3.

how would one design a surfing machine at a waterpark?


4.

what is cavitation?


5.

sports, flying gamepieces
:



curveballs
, tennis balls



knuckleballs



racquetballs near a wall

but not touching it seem to

interact with the wall



golf balls: drag, lift, dimples



magnitude of fluid forces that cause a dart thrown backward to flip around



kites



kayaking, eddies, etc.



boomerangs


6. drag:



affect of temperature



does the follower affect the leader



boat shape




7. transportation:



how much power does it take to pedal a bicycle on level ground? What
fraction is due to fluid resistance?



bus with rounded front, fuel savings



why is a car most efficient at some speed, like 55 mph in some cases



imagine a stationary
bike in calm room, zero tire and component friction:
what is the fluid dynamic drag



aircraft flight ceilings



wakes:
speedboats riding own wake
, why is there a wake, how does one
make a big or small wake and what are the relative merits



speedboat flips over



can a car drive upside down using fluid mechanics forces to hold it up to
the “ceiling”



does an airplane on a conveyor belt take off



tailgates and truck MPG



flooding: how strong to sweep people, cars away?



geometries of natural vs. man
-
made vessels: why d
oes a fish have an oval
cross
-
section but a submarine has more of a circular one



sailboat sail force compared to outboard motor



tacking, exceeding windspeed, etc.



do you really swim faster by shaving your legs, and how much



hydroplaning
; how fast to waters
ki or ski barefoot



accidentally driving a car into a lake



spoilers: when for style, when is there a real need



what could happen if the skin on an airplane wing could circulate


8. household fluid mechanics:



how strong is the force holding a mini
-
refrigera
tor shut right after some food is
removed



why does cold air come rushing out of a chest freezer with a horizontal lid


9. general/other



bumblebee shouldn’t be able to fly



resonance: pressure oscillation in car



watersnakes at Disney, DTW, etc.



are plasmas,

plastics, etc. fluids



turbulence: what and why



water bang / water hammer, and bandaids



can water flow uphill



are all liquids capable of hydrodynamic lubrication