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The principle of bernoulli

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					The principle of Bernoulli
Fluid dynamic
Physics concept
What will we learn????
Have you learned about continuity
 equation?
Ok, in this slide, we will learn about the
 principle of bernoulli.
Bernoulli explained the relation of pressure
 and velocity in fluid flow.
After read it, you will be able to explain the
 phenomenon around you!
    The principle of Bernoulli
     Look at this figure.




In that figure, the pressure in the same depth is same,
this phenomenon can be happened only in static fluid,
but how with dynamic fluid?
In the dynamic fluid, the pressure in the same
  depth is different.
The fluid flows from A to B, and the fluid go to
  the vertical pipe, the height of fluid in each
  pipes are different. We know that the height
  of fluid affects the pressure, remember the
  formulae: ρgh. So, we can say that the
 pressure will increase if the height is increase
 too! h~P
            E        C         D




       B              F             A
See the figure, in pipe C , the height of fluid
  is lowest of all. And its under(pipe F), has
  the smallest diameter. We know that the
  pipe F has the fastest velocity (remember
  the continuity equation lesson)
It shows us that the pressure will
  decrease if the velocity is increase!
Of above discussion, we can conclude that
Velocity is inversely to pressure.
How it can be done???
I’ve observed it. This phenomenon can be
   done , because fluid flow will move faster
   if the velocity faster too!
Because,the moving fluid is faster, so the
   volume of fluid also will be faster to move,
   in other words, the volume is less. In
   static fluid lesson,we know that P=ρgV.
if the volume is reduced, then the pressure
   will be reduced as well.
Around us
In the around us, we can find many the
  principle of bernoulli works!
What are they??
 The water flow
 The track of ball
 The plane window
 The bump
 Flying in the sky!
The water flow
Have you observed the water flow, yes, the flow
 will be narrowed,when out of the faucet!
      Why??
       The water flow hampers the velocity of air on edge.
       Because of that, the pressure around the water flow being higher.
       But,the pressure in the water flow is lower.
       So, the force of the air flow will constrict the water flow
       Remember: the air will move from high pressure to the lower
          pressure!

         The velocity of water makes the velocity of air in that flow
         faster than the velocity of air on the water flow edge


The force press
the water flow




                                      The water flow hampers the
                                      velocity of the air flow around its
The track of ball
                    You see your friends throw
                    a ball. And the ball doesn’t
                    move straigth,
                    What causes it?? You think
                    it’s caused by the wind??
                    How do you explain it?
                    Try to think about this
                    phenomenon before you
                    read the next slide!
                    Ok, if you have thought it,
                    let’s go to the next slide!!
        F       The condition:
                The ball moves to the left, so the direction of
            A   the wind velocity is to the right. The ball
W               spinning clockwise.
I
N               From that condition,we can analyze it!
D               The wind velocity In the A area is accelereted
                by the ball velocity, it’s caused the direction of
    B
                the wind velocity and the ball velocity is same in
                the A area!
                So,we can say that the pressure in the A area is
                lower.
                But how with the B area??
                The wind velocity in the B area is hampered by
                the ball velocity, so the wind velocity is slower.
                Look at the picture that the direction of the
                wind velocity and the ball velocity is not same in
                the B area! So ,we can say that the pressure in
                the B area is higher.

                Because there’s the difference of the pressure,
                so, arises a force of F that make the ball not
                move straight, but move in the direction of red
                arrow indicated
The plane window
                            What will we discuss???
                            Are you allowed to open the window
                            when the plane’s flying???? Why??
                            Can you explain why we are not
                            allowed to open it????




Have you ever opened
your car window when
your car’s running then a
paper (or other floaty
thing) suddenly moved out
through the window???
When the plane is flying, we are not allowed
  to open the window, because we and
  other passangers will be in the danger! We
  will be able to move out through the
  window. How it can be done?? Learn this
  explaination:
If we open the window, it will arise the
  difference of pressure.
You know that the wind velocity outside
  the plane faster than in the plane,
  don’t you??
It causes that we are not allowed to open
  the window!!
The bump
Look at the picture!
Such as the both of that boat, have
a machine that make them move
faster, then the both of them run
adjacent, so what will happen????
Yes! The bump will occur!!
Why????
Think it:
The both of boat run adjacent and they have the velocity of v. in the middle
of them ,the water flows faster than on the edge of the both of boat, so
arises the difference of pressure, and the force of F makes them bump!! 
                     The direction boat
                                                                     Note:
                                                                 Consider the
           V is                          V is                 velocity of the both
           slower        F               slower                of boat are same
                                 F

                        V is faster
                      Flying in the sky!

In this slide, I only explain about the
bird ,not plane(you can read about the
plane in other slide) how the bird
can fly in the sky???
Ok, at first we must know how the
structure of wings!
the birds have a curved wing that thick
in front of its!                          The bird can fly faster,
This structure makes the wind velocity    it’s caused by the
over the wings faster than under the      pushing wings to the
wings! So, arises the difference of       back, and in here the
pressure and also arises a force of F     newton’s law is used
that can lift the bird to fly.
Thanks to:
 Google images
 All blog/web that meritorious
SlideStreet.blogspot.com
 You just have been teached by reezar, one
  of the author slide street blog
 Thank you for reading!
 Read other slide that related

				
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posted:3/11/2011
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