Many features of fluid motion can be understood by
considering the behavior of an ideal fluid.
䡦 Idea fluid
¤ The fluid is nonviscous, which means there is no internal
friction force between adjacent layers.
¤ The fluid is incompressible, which means its density is
constant.
¤ The fluid motion is steady, meaning that the velocity, density,
and pressure at each point in the fluid don’t change with
time.
¤ The fluid moves without turbulence. This implies that each
element of the fluid has zero angular velocity about its
center, so there can’t be any eddy current present in this
moving fluid.