3. One Dimensional Flows

Question 1

Describe what is meant by a 1D flow

Answer 1

The velocity only has one non-zero component which varies in a direction perpendicular to the flow

Question 2

Describe plane Couette-Poiseuille flow

Answer 2

Flow of a fluid between two infinite planar walls

Question 3

Describe cylindrical Couette-Poiseuille flow

Answer 3

Flow in the axial direction through the gap between two infinitely long coaxial cylindders

Question 4

Describe circular Couette flow

Answer 4

Flow of a fluid in the azimuthan direction between two coaxial cylinders

Question 5

What are the three driving forces of the flow?

Answer 5

Pressure gradient
Gravity
Motion of the walls

Question 6

What is the difference between steady and unsteady 1D flows

Answer 6

Steady 1D flows are not a function of time
- Unsteady flows are the same as a steady 1D flow but now are a function of time

Question 7

What do we mean by “no body forces”

Answer 7

Neglect gravity