Laminar & Turbulent flow

Question 1

At low flow rates

Answer 1

With a low flow velocity the filament of
dye in the centre of the pipe was smooth
and steady.

Question 2

At intermediate flowrates

Answer 2

Question 3

At high flow rates

Answer 3

Further increase of flow rate increased the
filament fluctuations the dye filament
suddenly mixed across the tube

Question 4

Boundary layer

Answer 4

Question 5

What are the two types of flow

Answer 5

Laminar and turbulent flow

Question 6

laminar flow.

Answer 6

▪ At low flow rates, “Particles” of fluid are moving in straight lines. The
fluid can be considered as moving in layers or laminae.

Question 7

turbulent flow

Answer 7

At higher flow rates, the paths of individual fluid particles are not
straight but disorderly such that mixing takes place.

Question 8

What is the transition
region.

Answer 8

Between the fully-laminar and fully-turbulent flow

Question 9

▪ If the flow is laminar

Answer 9

viscous forces dominate and Re is small

Question 10

If the flow is turbulent

Answer 10

inertia forces dominate and Re is large.

Question 11

▪ For flow in a smooth circular pipe under normal engineering conditions the
following can be assumed:

Answer 11

▪Re < 2000: laminar flow
▪ 2000 < Re < 4000: transition
▪ Re > 4000: fully turbulent flow