Understanding the Conversion Formula for Venturimeter Readings

  • Thread starter Thread starter ujjwal kapil
  • Start date Start date
  • Tags Tags
    Doubt
AI Thread Summary
The discussion focuses on understanding the conversion formula for venturimeter readings, specifically how to convert differential manometer readings from mercury to water. A user encountered difficulties with the formula and provided a numerical problem for clarification. Participants suggest drawing a U-tube manometer to visualize the pressure differences and applying the ρgh formula to derive the pressure differential. There is a discrepancy noted between the derived conversion (20cm of Hg equals 272cm of H2O) and the provided solution (252cm). The conversation emphasizes the importance of including all variables, particularly the water column, in the calculations.
ujjwal kapil
Messages
2
Reaction score
0
Hi all

I was trying to solve some numerical problems on venturimeter. I got stuck due to a formula, that I was not able to make sense of. It is a conversion of reading of differential manometer in mercury to corresponding reading in water. I've attached the question, please help me understand it.
 

Attachments

  • rsz_untitled.jpg
    rsz_untitled.jpg
    79.1 KB · Views: 481
Physics news on Phys.org
Hi ujjwal kapil. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

Draw a U-tube manometer showing a difference in mercury levels. Now, add water above both surfaces of mercury, and show pressures of P1 and P2 acting on that water.

Apply your ρgh formula, etc., and derive the pressure differential P2 - P1 in terms of the other quantities present. Write your working here.
 
Last edited by a moderator:
I have found an answer, but not in accordance with the solution.
20cm of Hg= 272cm of H2O, but it is given as 252 in the solution.
 

Attachments

  • mano.jpg
    mano.jpg
    22.5 KB · Views: 482
Keep it simple, draw a symmetrical U-tube.

You overlooked the water! On one side you have P1 and a column of h metres of H2O balanced on the other side by P2 and a column of h metres of Hg.

So try this again. Keep it as algebra, don't substitute numbers. We're aiming towards that expression you circled, remember?
 
Thread 'Have I solved this structural engineering equation correctly?'

Thread 'Have I solved this structural engineering equation correctly?'

Hi all, I have a structural engineering book from 1979. I am trying to follow it as best as I can. I have come to a formula that calculates the rotations in radians at the rigid joint that requires an iterative procedure. This equation comes in the form of: $$ x_i = \frac {Q_ih_i + Q_{i+1}h_{i+1}}{4K} + \frac {C}{K}x_{i-1} + \frac {C}{K}x_{i+1} $$ Where: ## Q ## is the horizontal storey shear ## h ## is the storey height ## K = (6G_i + C_i + C_{i+1}) ## ## G = \frac {I_g}{h} ## ## C...
View full post »

Similar threads

B Resnick Halliday Krane: Venturimeter formula mistake?
Replies
4
Views
1K
Engineering Difficulty in Understanding Inverter Terms
Replies
2
Views
1K
How to Convert Lbm/ft^3 to kg/m^3?
Replies
9
Views
8K
Understanding Quaternion to DCM Conversion in Openshoe Matlab Library
Replies
2
Views
2K
Manometer Reading using Fluid Dynamics
Replies
6
Views
2K
Solving Diff. Eqn & Designing Circuits: An Understanding
Replies
18
Views
3K
Calculations for a capacitor charging from another capacitor
Replies
11
Views
3K
Mechanics of Materials — Torsional Stress on a Spinning Shaft
Replies
5
Views
3K
Comp Sci Unfamiliar Compilation Errors In a Linked List Class (C++)
Replies
2
Views
1K
Motor calculation for a rotating platform
Replies
7
Views
5K

Hot Threads

Recent Insights

Back
Top