Discharge Through a Vertical, Rectangular Orifice

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In this paper, the derivation  of a formula is presented to determine the time taken for the discharge of an open tank through a vertical, rectangular orifice. This formula allows a simpler  and more accurate determination of the discharge time.The formula obtained by the integration of velocity distribution was checked using a numerical model. It is shown the great correspondence between the derived formula and a formula for small orifices, regardles of whether the orifice is small or not, except in the cases where the height of orifice is much greater than the height of water level from the upper edge of the orifice. The presented formula takes into account the velocity distribution down the orifice and can be treated as a formula for all rectangular orifices
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Time of Fluid Discharge; Rectangular Orifice; Velocity Distribution; Torricelli´s Formula

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