Fluid Motion Flashcards
What is one velocity a function of?
It is a function of x, y, z, and t
What is the principle of continuity?
The total volume of the fluid entering the pipe is equal to the sum of the total volume of the fluid leaving the pipe and the volume of fluid held back inside the pipe.
What changes in 1D flows?
There are variations in pressure and velocity along one spatial coordinate
What changes in 2D flows?
The direction of flow and cross-flow
What is upstream?
The direction that is opposite to the flow direction
What is downstream?
The direction that follows the flow direction
What is a velocity profile?
A velocity profile is the speed of a fluid flow as a function of distance perpendicular to the direction of flow
What is a steady flow?
When a flow does not change with time
What does steadiness depend on?
The frame of reference
What is a streamline?
A streamline is defined as a line that is everywhere tangential to the instantaneous flow velocity.
What happens when streamlines cross?
The velocity component is zero
What must streamlines do?
- Must not cross
- Must run parallel to solid boundaries
What is a stagnation point?
When velocity is zero
How can fluid velocity be determined by streamline spacing?
U = 1/streamline spacing
What is the boundary that streamlines separate from?
Bluff bodies
