Why is the triangular notch preferred to measure small quantities of flow of water in laboratory?
When several forms of weirs or flumes might be used, the triangular-notch weir is often preferred because of its greater ac- curacy at low flows or its lesser sensitivity to approach-channel geometry and velocity distribution.
Why does the V notch give more accurate flow measurement?
In this case, the notch is “V” in shape. Depth of water above the bottom of the V is called head (H). The V-notch design causes small changes in discharge hence causing a large change in depth and thus allowing more accurate measurement than with a rectangular notch.
Why V notch is more accurate than rectangular notch?
The basic principle is that discharge is directly related to the water depth above the bottom of the V- notch, this distance is called head. The V-notch design causes small changes in discharge to have a large change in depth allowing more accurate head measurement than with a rectangular notch.
Why V notch is used for small discharge?
The v notch weir is especially good for measuring a low flow rate, because the flow area decreases rapidly as the head over the v notch gets small.
Why do we use V notch?
A v notch weir is simply a ‘v notch’ in a plate that is placed so that it obstructs an open channel flow, causing the water to flow over the v notch. It is used to meter flow of water in the channel, by measuring the head of water over the v notch crest.
Why does the V-notch give more accurate flow measurement than any other weirs and orifices when the flow is slightly fluctuating?
The V-notch design causes small changes in discharge hence causing a large change in depth and thus allowing more accurate measurement than with a rectangular notch.
What is the purpose of V notch and rectangular weir?
To conserve delivery head and reduce head loss, the rectangular and wide V-notch weirs rated by Kindsvater methods should be selected. These weirs provide the capability to use shorter heights from the approach channel invert to the crest.
Why do we use V notch in Charpy impact test?
The Charpy impact test, also known as the Charpy V-notch test, is a high strain-rate test that involves striking a standard notched specimen with a controlled weight pendulum swung from a set height. The impact test helps measure the amount of energy absorbed by the specimen during fracture.