Flow of Fluids
Content: Types of manometers, Reynolds numbers and its significance, Bernoulli’s theorem and its applications. Energy losses, Orifice meter, Venturimeter, Pitot tube and Rotameter.
Part 1:- Types of manometers
Part 2:- Reynolds numbers and its significance
Part 3:- Bernoulli’s theorem and its applications
Part 4:- Energy losses, Orifice meter, Venturimeter, Pitot tube and Rotameter.
Principles and Applications of Manometers:
- Most commonly used manometer
- it consists of a glass U shaped tube filled with a liquid A of density ρA kg /meter cude and above A the arms are filled with liquid B of density ρB.
- The liquid A and B are immiscible and the interface can be seen clearly.
- If two different pressures are applied on the two arms the meniscus on the one liquid will be higher than the other.
- Let pressure at point 1 will be P1 Pascal’s and point 5 will be P2 Pascal’s
THe pressure at point 2 can be wirtten as
Since ΔP = Δ hρg
(m+R) = distance from 3 to 5.
Since the points 2 nad 3 are at same height the pressure.
- Pressure difference can be determined by measuring R.
- Manometer are use in measuring flow of fluid.
- Simple Manometer helps in measuring the consumption of gases in the chemical reactions.
- Manometers are used in conjuction with flow meters for the measurement of flow of fluids. For example, Venturi meter and orifice meter are used for the measurment of pressure head using a manometer. Pitot tube measure the velocity head using manometer.
Point 4 = P1 + aρBg / gc + bρAg / gc
The last equation may simplified to
- Micromanometers based on the liquid column principle are available commercially.
- It measure the reading with extreme precision and sensitivity.
- These are free from errors due to capillary and require no calibration, apart from checking the micrometer scale.
Inclined Tube Manometers
- To measure small pressure differences need ot magnify Rm, some way.