Table of Contents
Why the divergent part of a venturi meter is longer than the convergent part?
The divergent part of a Venturi meter is longer than the convergent part to avoid flow separation. When liquid enters the convergent part in accordance with continuity it accelerates and retards while passing through the divergent part.
Why is the diverging angle in Venturimeter is smaller than converging angle?
The diverging section has an angle 5 to 15 degree. The diverging angle is less than the converging angle due to this length of the diverging cone is larger than converging cone.
Which part of the Venturimeter is larger?
This short portion has the minimum area and is known as the throat. The two conical portions have the same base diameter, but one is having a shorter length with a larger cone angle while the other is having a larger length with a smaller cone angle.
Why the downstream cone angle is less than upstream cone angle in a Venturi meter?
In this meter the fluid is accelerated by its passage through a converging cone of angle 15-20o. Since separation does not occur in a contracting cross section, the upstream cone can be made shorter than the downstream cone with but little friction, and space and material are thereby conserved. …
Why the length of convergent cone is less than length of divergent cone?
Answer: Since flow separation is not experienced while converging, the converging section is shorter. Maximum value of cone angle of converging section is as such to avoid vena contracta such that flow area is minimum at throat. Because it reduce the backward motion of flow.
What is the section of throat in Venturi meter?
The venturi meter consists of a main piece of pipe that decreases in size to a section called the throat, followed by a gradually increasing size back to the original pipe size. The liquid pressure at the main pipe section 1 is denoted by P1 and that at the throat section 2 is represented by P2.
What happens if the length of a divergent section is not long?
Its all depend on angle not on the length. For divergent section, if the length is not longer than the angle would be steep and back pressure will be applied to the fluid. This is done to avoid flow separation. Flow separation and recirculation regions typically occur when adverse pressure gradients occur.
What happens when a venturi meter is reversed?
On reversal of the venturi meter this diverging portion length decreases which may lead to high +ve pressure gradient than the previous case and hence the chance of flow separation or flow reversal increases.
Why does a divergent Venturi cause more power consumption?
Due to more chance of flow reversal at the divergent portion of venturi it may lead to more power consumption and cause vibration due to irregular dischagre.
What causes recirculation and flow separation in a venturi?
Flow separation and recirculation regions typically occur when adverse pressure gradients occur. Its present in almost all flow related areas. For a venturi, its always better to keep a smaller divergence angle since the flow is subsonic.