Question

Laws and Numbers Reynolds Number, Re Mach Number, M Knudsen Number, Kn Torricelli's Law Archimedes' Principle

Answer 1

1) Reynolds number: In fluid mechanics, the Reynolds number(R_e) is a dimensionless quantity that is used to help predict similar flow patterns in different fluid flow situations.The Reynolds number is defined as the ratio of inertial forces to viscousforces and consequently quantifies the relative importance of these two types of forces for given flow conditions.laminar flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motion while turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, which tend to produce chaotic eddies and other flow instabilities.

2. Mach number: In fluid dynamics, the Mach number (M) is a dimensionless quantity representing the ratio of flow velocity past aboundary to the local speed of sound.

3.Knudsen number:The Knudsen number(Kn) is a dimensionless number defined as the ratio of the molecular mean free path length to a representative physical length scale.

4.Torricelli law:Torricelli's law states that the speed of efflux,v, of a fluid through a sharp-edged hole at the bottom of a tank filled to a depth h is the same as the speed that a body (in this case a drop of water) would acquire in falling freely from a height h.

5. Archimedes principle:Archimedes's principle indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and it acts in the upward direction at the centre of mass of the displaced fluid.