CHAPTER 1: Fundamental Properties of Fluids Flashcards
the science that deals with the
action of forces on fluids at
rest, as well as in motion
Fluid mechanics
the study of the effect of forces on fluid motion
fluid dynamics
branch of science concerned with the practical applications of fluids, primarily
liquids, in motion
Hydraulics
2 States of Matter
- Solid
- Fluid
Because molecules in ____ state are spaced very closely, it possess compactness and rigidity of form.
solid
2 forms of fluids
liquid and gas
A liquid has a ______ and gas does not.
free surface
Liquids are practically ___________-
while gases are ___________.
incompressible ; compressible
The weight per unit of volume of a fluid
Specific/Unit weight, γ
The volume occupied by a unit mass of fluid
Specific volume, 𝑉s
The amount of resistance of a fluid
to shearing forces. It describes the
internal friction of a moving fluid
Viscosity, μ
The ratio of dynamic viscosity of
the fluid, μ, to its mass density, ρ.
Kinematic Viscosity, ν
cohesion and momentum transfer occur in _______
Liquids
transfer of molecular momentum occur in _____
gases
For liquids:
Viscosity _____ as temperature__________
decreases; increases.
For Gases
Viscosity _____ as temperature__________
increases; increases
A contractive tendency of
the surface of a fluid that
allows it to resist an external force.
Surface tension, σ
The movement of a liquid
through a thin-bore tube
Capillarity
It can be defined as the force exerted by the
vapor.
Vapor Pressure
to exert the vapor pressure, the vapor should be in ___________ with its liquid or solid phase.
equilibrium
to exert the vapor pressure, Vapor should be at a ____________-
constant temperature.
to exert the vapor pressure, both vapor and its condensed form should exist in a _______________
closed system.
A fluid that is both incompressible and
have no viscosity. Its bulk modulus is infinite. It has
no surface tension.
Ideal fluid
A fluid that possesses viscosity, finite
compressibility and surface tension
Real fluid
A fluid in which the shear stress is
directly proportional to the shear strain or velocity
gradient
Newtonian fluid
A real fluid that doesn’t follow
the Newton’s law of viscosity.
Non-Newtonian fluid
The viscosity of these fluids
decreases as the stress increases
Pseudoplastic fluid
A fluid which viscosity increases as
stress is applied
Dilatant fluid
It does not flow until a critical
stress (yield stress) is exceeded and then flows at a
rate proportional to the excess of stress over the
yield stress
Bingham plastic
There is a decrease in viscosity
with time under a constant applied shear stress.
Thixotropic fluid
Fluid that has an increase in their
viscosity as the time of application of stress
increases
Rheopectic fluid
