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8/12/2019 ENGG 2230 - Week 3 - Ch2 Pressure Distribution-Part IV (1)
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Fluid MechanicsChapter :Pressure Distribution in a FluidPart IV
Week 3 Lecture Notes
J. LevisonENGG 2230 Winter
Lecture 6
Thursday, January 23, 2014
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Todays Lecture
Do buoyancy (stability) example
Pressure distribution in rigid body motion
Linear acceleration
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References
F.M. White, Fluid Mechanics, McGraw-Hill, 2011.
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Example 2.6:
A barge is 4.5 m wide and 12 m long andfloats with a draft of 1.2 m. It is piled so high
with gravel that its centre of gravity is 0.6 m
above the waterline. Is it stable?
[draft = vertical distance between the waterline and the
bottom of the hull]
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Fluids in motion
Were almost ready to start studying this
BUT, first we can study one category using
fluid statics concepts
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Whole fluid moves as if it were a rigid (i.e., non-
deforming) body
Individual particles are not deforming (even
though they might be in motion)
Examples:1) fluid traveling on a tank in a train (linear acceleration)
2) cylinder of liquid in rotation at a constant angular speed (rigid-
body rotation)
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Rigid Body Motion
A special case where all particles are incombined translation and rotation with no
relative motion between particles
Sometimes referred to as relative equilibrium With no relative motion, there are no shear
strains or strain rates
Accelerating fluid will t i l t under uniform rigidbody acceleration (like an accelerating glass
of water)
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Accelerating Fluid
9(White: Fig. E2.13)
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Tilt in gof Fluid in Rigid Body Acceleration
10(White: Fig. 2.21)
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Example 2.7:
The tank of liquid in the
figure accelerates to theright with the fluid in rigid
body motion.
a. Compute axin m/s2
b. Why doesnt the solutionin part a depend on the
fluid density?
c. Determine the gauge
pressure at point A if thefluid is glycerin at 20C.
11(White)
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Example 2.8:
The same tank as beforeis now moving with
constant acceleration up a
30 inclined plane.
Assuming rigid body
acceleration compute:
a. The acceleration, a
b. Whether the acceleration
is upwards or downwards
c. Determine the gauge
pressure at point A if the
fluid is mercury at 20C.
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Homework
Assignment #2finish by Sunday(Assignment 1 solutions were posted last Sunday)
Read Sections 3.13.5
Reminder for Week 2 lab groups:
Lab reportsdue by 5 pm one week after you
perform the lab
Submission box #12 in THRN
Review marking scheme in the lab manual
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