Fluid in physics refers to liquids and gases.
To study fluid flow we have to make the following assumptions:
We consider fluids to be incompressible
We assume that they have little or no internal friction or viscosity.
Streamline and turbulent flow.
The path followed by a small element of a moving fluid is called a line of flow . A streamline is a curve whose tangent at any point is in the direction of the fluid velocity at that point.