FLUID MECHANICS
Horsepower
a unit of measurement of power, equivalent to 33,000 ft-lb/min or 550 ft-lb/ sec
Density, ρ
mass per unit volume
Gauge pressure
measure above the existing atmospheric pressure. It is the excess of absolute pressure
Vacuum gauge
measure vacuum pressure
Pressure gauge
measures gauge pressure
Laminar flow
occurs when Reynolds number (Re) is 2000 or less
Nonuniform flow
occurs when the depth of flow changes along the length of the open channel. It may be steady or unsteady.
10^-12
pico
Vacuum pressure
pressure below atmospheric pressure
Uniform flow
refers to the condition in which the depth, slope, velocity, and cross section remain constant over a given length of channel
Steady flow
refers to the condition in which the flow characteristics (velocity, depth, etc) at any point do not change with time.
Pressure
refers to the effects of a force exerted by a solid, liquid, or gas against and distributed over a surface
pressure
s commonly given in units 𝑙𝑏/𝑓𝑡 2 (𝑝𝑠𝑓), 𝑙𝑏/𝑖𝑛 2 (𝑝𝑠𝑖), 𝑃𝑎 (𝑁/𝑚2 ), or sometimes expressed in terms of depth of a liquid (cm, in, ft, or m).
Total energy (E)
s the sum of its potential energy (PE), Kinetic energy (KE), and pressure/flow energy (FE)
Mechanics
science that deals or describes and predicts the conditions of rest or motion of bodies under the action of forces.
1
specific gravity of water
13.57
specific gravity of water
101.325 kPa
standard atmospheric pressure
Archimedes' principle
states that "A body floating or submerged in a fluid is buoyed (lifted) upward by a force equal to the weight of the fluid that would be in the volume displaced by the fluid".
Momentum
term applied to a body which is in motion. This is the product of its mass and the velocity at any instant
Energy
the capacity for doing work.
Kinetic Energy (KE)
the energy possessed by an object or body by virtue of its motion.
Potential Energy (PE)
the energy possessed by an object or body by virtue of its position.
Absolute pressure
the measure of pressure above zero.
Atmospheric pressure
the pressure due to the force exerted in the atmosphere
Mass (m)
the quantity of matter a body contains irrespective of the kind of material of which it is composed.
Specific Weight
the weight of a unit volume of the substance.
displacement
this is the distance when movement is being measured.
Vapor Pressure
this is the pressure created by the vapor molecules when evaporation takes place within an enclosed space.
Specific Volume, p
this is the reciprocal of the density.
laminar flow turbulent flow
two types of flow of fluids
Contracted Weir
weir where its length is less than the width of the channel
Suppressed Weir
width of crest almost equal to width of channel.
𝑃 𝑔𝑎𝑢𝑔𝑒
𝑃 𝑎𝑏𝑠 − 𝑃(𝑎𝑡𝑚)
𝑃 𝑣𝑎𝑐
𝑃 𝑎𝑡𝑚 − 𝑃(𝑎𝑏𝑠)
P abs
= 𝑃 𝑔𝑎𝑢𝑔𝑒 + 𝑃 𝑎𝑡m
Pressure measuring devices
Barometer Piezometer Manometer Pressure gauge Vacuum gauge
Pressure Difference
Difference in pressure between any two points at different levels in a liquid
Francis Weir
Rectangular Weir
english system (mass)
Slug = lb-sec^2/ft
gravity force
The force exerted on a body by gravitation
center of buoyancy
The point through which the buoyant force acts
Power (P)
The rate at which work is done
Work (W)
The results of force acting (or moving) through a distanc
Viscosity (𝝁)
This is the term used to describe the resistance of fluid to flow
Cipolletti Weir
Trapezoidal weirs where its side slopes are equal to ¼ (1 horizontal, 4 vertical)
V-notch Weir
Triangular weir
Weirs
are structures built across open channels to measure the rate of flow of liquid usually water.
Fluid
are substances which are capable of flowing and which conform to the shape of containing vessels. It may be divided into liquids and gases.
Fluid Mechanics
branch of applied mechanics dealing with the behavior of fluids at rest and in motion
Barometer
device for measuring atmospheric pressure
Manometer
device for measuring fluid pressure. It consists of a bent tube (or tubes) containing one or more liquid of different SG.
Piezometer
device use to measure pressure of liquid by means of tube attached to the wall of the container or conduit
Pressure
expressed as force (F) divided by area
Laminar flow
fluid particles move along straight, parallel paths in layers
Turbulent flow
fluid particles move in haphazard fashion in all directions.
metric system (mass)
g, kg
Specific energy
is defined as the energy per unit weight (ft-lb/lb or N-m/N) relative to the bottom of the channel.
Force (F)
is the action which causes or tends to cause motion of an object.
orifice
it is an opening with a closed perimeter through which fluid flows.
Time (T)
it is defined as interval of duration
Nonuniform flow
it occurs when the depth of flow changes along the length of the open channel. It may be steady or unsteady.
