Lesson 2: Properties of Fluids

Question 1

any characteristic of a system

Answer 1

property

Question 2

independent of the mass of the system; (ex. temperature, pressure, density)

Answer 2

intensive property

Question 3

depend on the size; (ex. mass, volume)

Answer 3

extensive property

Question 4

extensive properties per unit mass; specific volume, total energy

Answer 4

specific property

Question 5

The state of a simple compressible system is completely specified by two independent, intensive properties

Answer 5

state postulate

Question 6

equation that relates the pressure, temperature, and density of a substance Ex: ideal gas equation of state

Answer 6

equation of state

Question 7

temperature at which pure substance changes phase (at 1 atm, the saturation temperature of water is 100 degrees Celsius)

Answer 7

saturation temperature

Question 8

pressure at which a pure substance changes phase

Answer 8

saturation pressure

Question 9

pressure exerted by its vapor in phase equilibrium with its liquid at a given temperature

Answer 9

vapor pressure

Question 10

pressure of a gas or vapor in a mixture with other gases

Answer 10

partial pressure

Question 11

is the sum of the partial pressure of dry air and the partial pressure of water vapor

Answer 11

atmospheric pressure

Question 12

what increases with vapor pressure?

Answer 12

temperature

Question 13

vapor bubbles collapse as they are swept away from low-pressure regions, generating highly destructive, extremely high-pressure waves

Answer 13

cavitation

Question 14

sum of all numerous forms of energy of a system

Answer 14

total energy, E

Question 15

by the contact (or wetting) angle ϕ – angle that the tangent to the liquid surface makes with the solid surface at the point of contact

Answer 15

microscopic energy

Question 16

sum of all microscopic forms of energy (U)

Answer 16

internal energy

Question 17

energy related to motion and the influence of some external effects such as gravity, magnetism, electricity, and surface tension.

Answer 17

macroscopic energy

Question 18

energy that a system possess as a result of its motion

Answer 18

kinetic energy

Question 19

energy that a system possess as a result of its elevation in a gravitational field

Answer 19

potential energy

Question 20

a simple compressible system is absent of what?

Answer 20

magnetic, electric, and surface tension

Question 21

what does it mean if k value is large

Answer 21

large pressure is needed to cause a fractional change in volume (incompressible)

Question 22

The force a flowing fluid exerts on a body in the flow direction; depends on viscosity

Answer 22

drag force

Question 23

characteristics of newtonian fluids

Answer 23

• Rate of deformation is linearly proportional to shear stress
• Water, air, gasoline, oil
• Plot of shear stress vs rate of deformation (velocity gradient) is a straight line

Question 24

viscosity unit, equivalent to 0.1 Pa s

Answer 24

poise

Question 25

Non-linear relationship between shear stress and rate of deformation

Answer 25

non-newtonian fluids

Question 26

apparent viscosity increases with the rate of deformation

Answer 26

dilatant (shear thickening fluids)

Question 27

apparent viscosity decreases with the rate of deformation

Answer 27

Pseudoplastic (shear thinning fluids)

Question 28

substances that resists a finite shear stress and thus behave as a solid, but deform continuously when the shear stress exceeds the yield stress and behave as a fluid

Answer 28

bingham plastic