This simulation calculates and displays the volumetric and mass flow rates of a liquid maintained at a constant height in a tank as a function of the liquid’s height \( h \) and density \( \rho \), the drain pipe’s diameter \( d \) and the discharge (orifice) coefficient \( c_{0} \). It also plots the volumetric flow rate curve as a function of the liquid’s height for the chosen drain diameter and discharge coefficient values and displays a schematic diagram of the system. The discharge (orifice) coefficient \( c_{0} \) characterizes the relationship between actual flow and ideal flow through an orifice. An orifice with discharge coefficient of 1.0 behaves as if pressure drop across the orifice (\( \Delta p \)) is zero. An orifice with a discharge coefficient near zero restricts flow significantly, even at large pipe diameters.