Flow from a Tank at Constant Height

Snapshot 1: water flow from a narrow drain

Snapshot 2: oil flow from a wide drain

Snapshot 3: concentrated sugar syrup flow from a narrow drain

This Demonstration depicts the flow from a tank where the liquid is maintained at a constant height. It shows that the liquid's flow rate is proportional to the square root of its height. The program calculates the volumetric flow rate, , using a slightly modified Bernoulli equation , where is the gravitational constant (9.81 ), is the liquid's height in the tank (m), is the discharge (orifice) coefficient (dimensionless), and the drain diameter (cm). The corresponding mass flow rate (kg/s) is calculated by multiplying the volumetric flow rate, , by the liquid's density, ().

References:

R. L. Earle and M. D. Earle, Unit Operations in Food Processing, NZIFST, Inc., 1983.

V. L. Streeter, E. B. Wylie, and K. W. Bedford, Fluid Mechanics, 9th ed., Boston: WCB/McGraw-Hill, 1998.