Topic 4 Flashcards
1
Q
What is a viscous fluid?
A
Fluids that have internal friction
Dependent on fluid and temperature.
2
Q
Give Newton’s Friction Law
A
F = ηA (Δv/Δy)
- η = Viscosity*
- A = Area*
- y = Thickness of the layer*
3
Q
What is Laminar Flow?
A
The closer the layer of fluid in a tube to the centre, the higher the velocity of the layer.
Laminar flow is often when the velocity is low.
4
Q
What is the Parabolic Velocity Profile?
A
vmax = (ΔPR2)/(4ηl) = 2vmean
Shows that velocity is highest in the centre, and decreases at the wall.
5
Q
Give the equation of Poiseuille’s Law
A
Q = ΔPπR4/(8ηl)
6
Q
What does Poiseuille’s Law indicate?
A
High viscosity leads to low flow rate
Flow rate is proportional to pressure
Flow rate is proportional to R4
7
Q
Equation to calculate the Power for maintaining laminar flow
A
P = Fvmean
