I am a mechanical engineering graduate. working in Chennai. My question is regarding fluid flow from a tank. I consider a water tank of diameter 'D' meters with 'h' meters of water column and with a orifice of diameter 'd' mm. The Bernoulli equation says sum of pressure energy, kinetic energy and potential energy is constant for a fluid at any point in the flow field. Rearranging the energy terms a equation for velocity can be derived in terms of pressure energy and potential energy. The size of the orifice does not feature in this equation. So irrespective of the orifice diameter will the water flow out of tank with same velocity? This is my question. Can anybody please help me?