Hydraulics Flashcards
Hydraulics - the study & ______of
______. Both in _____and at _____
Hydraulics - the study & behaviour of
water. Both in motion and at rest
How are the following measured
- Pressure =
- Velocity =
- Flow =
- Pressure = force (newtons) / area (m²)
- Velocity = speed of water (km/h or m/s)
- Flow = litres / minute (lpm or l/min)
“_____applied to a confined ____at any point is ______
undiminished throughout the fluid in all ____and acts upon
every part of the _____vessel at ____angles to its interior
surfaces and ____upon equal areas
“pressure applied to a confined fluid at any point is **transmitted **
undiminished throughout the fluid in all directions and acts upon
every part of the confining vessel at right angles to its interior
surfaces and equally upon equal areas
6 principle characteristics of pressure in liquids
1. Pressure is _______ to any ______on which it acts.
2. Pressure at any ____of a ___at ____is the same _____in
all _______.
3. Pressure applied from ____to a fluid contained in a _____
is transmitted ____in all directions.
4. _____pressure of a fluid in an ______vessel is ________
to its ______.
5. The ______pressure of a fluid in an ______vessel is
_______to the _____of the fluid.
6. The downward pressure of a fluid on the _____of a vessel is
_________of the _______of that vessel.
6 principle characteristics of pressure in liquids
1. Pressure is perpendicular to any surface on which it acts.
2. Pressure at any point of a fluid at rest is the same intensity in
all directions.
3. Pressure applied from outside to a fluid contained in a vessel
is transmitted equally in all directions.
4. Downward pressure of a fluid in an open vessel is **proportional **
to its depth.
5. The downward pressure of a fluid in an open vessel is
proportional to the density of the fluid.
6. The downward pressure of a fluid on the bottom of a vessel is
independent of the shape of that vessel.
Which law is this?
- Pressure is perpendicular to any surface
on which it acts.
Which law is this
- Pressure at any point of a fluid at rest is of
the same intensity in all directions.
Which law is this?
- Pressure applied from outside to a fluid
contained in a vessel is transmitted equally
in all directions.
Which law is this?
- Downward pressure of a fluid in an open
vessel is proportional to its depth.
Which law is this?
- The downward pressure in an open vessel
is proportional to the density of the fluid.
Which law is this?
- The downward pressure of a fluid on the
bottom of a vessel is independent of the shape
of that vessel.
Characteristics of Pressure
• ___sides
• Position of ____
• Pressure on all ____due to the ____of
the water – _____to those sides
as indicated by the arrows
Characteristics of Pressure
• Flat sides
• Position of rest
• Pressure on all sides due to the weight of
the water – perpendicular to those sides
as indicated by the arrows
Characteristics of Pressure
• ____or hose
• Insert gauges
• Valve or branch ____
• Water at ____
• Gauges register ____readings
showing the ____pressure at any ____
Characteristics of Pressure
• Pipe or hose
• Insert gauges
• Valve or branch closed
• Water at rest
• Gauges register identical readings
showing the same pressure at any point
Characteristics of Pressure
• Pressure at the ____is exactly the ____
in the three vessels, providing that the
____of the liquid or ____is the ____in
each case
Characteristics of Pressure
• Pressure at the base is exactly the same
in the three vessels, providing that the
depth of the liquid or head is the same in
each case
Water - Characteristics
• At normal atmospheric pressure (___kPa)
– Freezing point – ____
– Boiling point – ____
– ____ ≈ 1kg
– 1 m3 = ____ litres
• Virtually _____
• ______of ______any change in vessel
shape
• Relatively high _____ ______
Water - Characteristics
• At normal atmospheric pressure (101 kPa)
– Freezing point – 0o C
– Boiling point – 100o C
– 1 litre ≈ 1kg
– 1 m3 = 1000 litres
• Virtually incompressible
• Incapable of resisting any change in vessel
shape
• Relatively high surface tension
Water - Characteristics
• Water in it’s various forms (salt, fresh, dirty,
drinking) has varying _______.
Water - Characteristics
• Water in it’s various forms (salt, fresh, dirty,
drinking) has varying densities.
Atmospheric Pressure
• Atmospheric pressure is the pressure
_____against a _____by the weight of
_____above (Earth’s atmosphere)
• Atmospheric pressure (at mean sea level) = ______kPa
Atmospheric Pressure
• Atmospheric pressure is the pressure
exerted against a surface by the weight of
air above (Earth’s atmosphere)
• Atmospheric pressure (at mean sea level) = 101.3 kPa
Practically, 10m lift is not ____, due to:
• ____
•____ ____
•_______ ________> leaks, seals
Practically, 10m lift is not achievable, due to:
• Altitude
•Friction loss
•Equipment limitations > leaks, seals
To _____water through hose or pipe, work
has to be performed to _____ _____
which is caused by water particles _____
against each other and the _____surface of
the hose or pipe.
_____to carry out this work is obtained from
the difference in _____, or _____, existing
between the two ends of the hose or pipe.
To propel water through hose or pipe, work
has to be performed to **overcome friction **
which is caused by water particles **rubbing **
against each other and the interior surface of
the hose or pipe.
Energy to carry out this work is obtained from
the difference in pressure, or head, existing
between the two ends of the hose or pipe.
5 Friction Loss Laws
- Length
- Diameter
- Velocity
- Roughness
- Pressure
Length
Friction loss varies directly with the length of the pipe.
____the length - _____the friction loss
Length
Friction loss varies directly with the length of the pipe.
Double the length - double the friction loss
Diameter
For the same ____, friction loss __________ directly
with the _______in diameter.
______diameter –___friction loss –______flow
Diameter
For the same velocity, friction loss decreases directly
with the increase in diameter.
Double diameter –1/2 friction loss –Quadruple flow
Diameter
- Diameter _____
- Surface Area _____
- Flow ______
- Friction Loss ______
Diameter
- Diameter doubled
- Surface Area doubled
- Flow **quadrupled **
- Friction Loss **halved **
Diameter
To _____friction loss,
always use the ______diameter hose
or pipe that is _______.
Diameter
To minimise friction loss,
always use the largest diameter hose
or pipe that is practical.
Velocity
Friction loss increases directly as the **square **of the **velocity.
Halve **velocity -1/4 friction loss
Velocity
Friction loss increases directly as the square of the velocity.
Halve velocity -1/4 friction loss
