Mechanical Engineering - Hydraulics and Fluid Mechanics - Discussion

For a broad crested weir 2L>H.

If the height of water above the weir crest is not greater than two times of the width of the crest of weir, the weir is called a Broad Crested weir.

A weir is structure which is made of concrete and used to measure discharge of dam.

Please justify the answer clearly.

A structure, used to dam up a stream or river, over which the water flows, is called a weir. The conditions of flow, in the case of a weir, are practically the same as those of a rectangular notch.

An obstruction that allows the liquid to flow over it is called a weir.

Crest is a horizontal top edge of weir on which the liquid flows.

Broad crested weir: A broad crested weir is a rectangular block of width (or length) , w and height, p and w>p. As its name implies that this type of weir has a broad (large width) crest. In broad crested weir the width of the crest of the weir is more than half the height of water above the weir crest.

A broad-crested weir is a flat-crested structure, with a long crest compared to the flow thickness. When the crest is "broad", the streamlines become parallel to the crest invert and the pressure distribution above the crest is hydrostatic. The hydraulic characteristics of broad-crested weirs were studied during the 19th and 20th centuries. Practical experience showed that the weir overflow is affected by the upstream flow conditions and the weir.

Please justify the answer clearly.

Crest is the bottom edge of weir over which the water flows.

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