Fluid those Substances which can flow from one point to the other are called fluid . Fluid flow : when fluid is in motion , its flow can be, streamline flow; tarbulent flow; (1): streamline flow: the flow is said to be streamline or laminar if every partial that passes a particular point , moves along exactly the same path as followed by the particles which passed that point earlier.or, if velocity of the particles at different points does not change with time, the flow is called streamline flow. in this case each particles of fluid moves along a smooth path.the different streamline can not Cross each other. this condition is called steady flow condition. if the streamline cross each other the particle will go in one direction or other and flow will not be steady,it will be a turbulent flow. (2):Turbulent flow: the irregular or unsteady flow of the fluid is called turbulent flow. ideal fluid: such a fluid which satisfy the following conditions is called an ideal fluid. (I); the fluid is non viscous i.e there is no internal frictional force between adjacent layer of fluid. (ii); the fluid incompressible i.e its identity is constant. (iii): the fluid motion is steady.
