week 6

Question 1

how is viscosity caused

Answer 1

by the cohesive forces between the molecules in

liquids, and by molecular collisions in gases

Question 2

what develops when two layers of the same fluid move relative to each other

Answer 2

a friction
force develops between them and the slower layer tries to slow down
the faster layer

Question 3

internal resistance to flow is called?

Answer 3

viscosity

Question 4

what is viscosity

Answer 4

is the measure of internal stickiness of the fluid.

(Honey for example has a
much higher viscosity than water)

Question 5

what is the NO-SLIP condition

Answer 5

the fluid will have zero velocity relative to the boundary. The fluid velocity at all fluid–solid boundaries is equal to that of the solid boundary.

Question 6

what is Velocity Boundary Layer

Answer 6

fluid flows over a stationary surface, the fluid touching the surface is brought to rest by the shear stress to at the wall

Question 7

what is the boundary layer

Answer 7

very thin layer of fluid over the surface of

an object, which allows the fluid to change its velocity fromthe upstream value to zero on the surface

Question 8

what is turbulent boundary layer

Answer 8

the flow is highly irregular and is characterized by random, three
dimensional motion.

Question 9

what is laminar boundary layer,

Answer 9

the fluid flow is highly ordered and it is possible to identify streamlines along which the fluid particles move