How Do You Calculate the Speed of Air Over a U-Tube?

  • Thread starter Thread starter thenewbosco
  • Start date Start date
  • Tags Tags
    Air Speed
AI Thread Summary
To calculate the speed of air over a U-tube, one must consider the pressure difference created by the height of the fluid columns. The height difference of 1.25 cm needs to be converted into pressure using the density of the fluids involved. The equation should incorporate the atmospheric pressure (Po) and the pressure due to the height of the fluid (density * g * h) on both sides of the U-tube. The challenge lies in factoring the speed of the air into the pressure equation on the left side, where the air is blown. Understanding how the air's density affects the overall pressure balance is crucial for solving the problem.
thenewbosco
Messages
185
Reaction score
0
A problem i have encountered:

diagram at http://img.photobucket.com/albums/v11/biggm/dia.jpg

Here is a u-tube open at both ends partially filled with water and oil with given density is poured in the right column so the height of the oil is 5.0 cm.

i have calculated the difference in height to be 1.25 cm.
in the second picture, air motion on the right is shielded while air is blown over the left opening until the surfaces are at the same height.
i am to calculate the speed of the air taking the density of air to be
1.29kg/m^3.

I do not know how to create the equation needed to solve this.
i am thinking i need to find the external pressure minus the effect of the blown air on the left since it is less than the right which is just the external atmospheric pressure.

thanks for help on this
 
Last edited by a moderator:
Physics news on Phys.org
anyone... .
 
someone ...anyone
 
right..the equation should be the same as last time for the two depths, but how does the speed of the air factor into the Po. On the side with the shield it will be just Po + density*g*h and on the other side it will be P + density*g*h. How can i factor the air into the equation for P on the left?

it must be Po - effect of air...but how
 
Last edited:
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Mercury barometer with a small amount of air
Replies
7
Views
2K
Understanding Pressure and Volume in a U-shaped Tube
Replies
13
Views
3K
Density of Flow Along a Tube Under the Action of Advancing Piston
Replies
11
Views
1K
What are the air speeds in a Venturi meter with varying tube diameters?
Replies
2
Views
8K
How Does Air Pressure Affect Fluid Levels in a U-Shaped Tube?
Replies
5
Views
3K
Calculating Air Speeds in a Venturi Tube Using Conservation of Fluid Mass
Replies
1
Views
3K
Fluid Statics- u-tube displacement
Replies
2
Views
6K
Change in pressure of a gas inside a tube
Replies
6
Views
2K
How to determine air velocity in open ended tube?
Replies
9
Views
2K
U-Tube (Pv=nRT, Pascals) Problem
Replies
15
Views
2K

Hot Threads

Recent Insights

Back
Top