Module 2: Fluid Flow Phenomena

Question 1

this describes how the velocity of a fluid changes with position, usually in the direction perpendicular to the flow

Answer 1

velocity gradient

Question 2

two types of fluids

Answer 2

1. newtonian fluids
2. non-newtonian fluids

Question 3

this happens when forces are applied parallel, not perpendicular to a surface

Answer 3

shear stress

Question 4

two type of non-newtonian fluids

Answer 4

1. dependent of time
2. independent of time

Question 5

this is directly proportional to velocity gradient

Answer 5

shear stress

Question 6

this becomes less viscous as shear rate increases

Answer 6

pseudoplastic fluids

Question 7

examples of non-newtonian fluids that are dependent of time

Answer 7

1. thixotropic fluids
2. rheopectic fluids
3. viscoelastic fluids

Question 8

it is the force per unit area that causes one layer of a material (like a fluid) to slide or deform relative to another layer

Answer 8

shear stress

Question 9

this is a tangential stress that acts along the surface

Answer 9

shear stress

Question 10

this is especially used when studying viscosity and laminar flow

Answer 10

velocity gradient

Question 11

this is due to fluid viscosity

Answer 11

friction

Question 12

shear stress is directly proportional to?

Answer 12

velocity gradient

Question 13

examples of non-newtonian fluids that are independent of time

Answer 13

1. bingham plastic
2. pseudoplastic fluid
3. dilatant fluid

Question 14

this becomes more viscous the longer stress is applied

Answer 14

rheopectic fluid

Question 15

this shows both solid and fluid behavior

Answer 15

viscoelastic fluid

Question 16

these fluids follow the Newton’s Law of Viscosity

Answer 16

newtonian fluids

Question 17

this is a dimensionless number which is a ratio of inertial forces to viscous forces

Answer 17

reynold’s number

Question 18

these fluid do not follow Newton’s Law of Viscosity

Answer 18

non-newtonian fluids

Question 19

this doesn’t flow until a minimum yield stress is reached

Answer 19

bingham plastic

Question 20

this becomes more viscous as shear rate increases

Answer 20

dilatant fluid

Question 21

this is used in categorizing fluids systems in which the effect of viscosity is important in controlling the velocities or flow pattern of a fluid

Answer 21

reynold’s number

Question 22

two types of normal stress

Answer 22

1. compressional stress
2. tensile stress

Question 23

this becomes less viscous the longer stress is applied

Answer 23

thixotropic fluids