3.2 Type of flow

·         refer to flow of an ideal flow and real fluid

An ideal fluid flow is

•  Incompressible – the density is constant
•  Irrotational – the flow is smooth, no turbulence
• Nonviscous – fluid has no internal friction ( η = 0)
• Steady flow – the velocity of the fluid at each point is
• constant in time.
• When flowing in a straight conduit, all particle move in parallel lines with equally velocity

 

A real fluid flow is

• Compressible – their density is a function of absolute pressure and absolute temperature
• Viscous – fluid encounter internal resistance when flow
• Unsteady flow – flow properties at a point change with time
• When flowing in a straight conduit, the velocity adjacent to the wall will be zero, it will increase rapidly with short distance from the wall. 

Next path line http://fluidbloggroup3.blogspot.com/2014/05/33-path-line.html