Understanding flow and velocity
Any referenced datasets can be downloaded from "Module downloads" in the module overview.
Transcript
00:03
Before modeling water supply networks,
00:05
you must have a basic understanding of
00:07
the terminology used when discussing water pressure
00:10
flow is a unit of volume moving past a certain point within a unit of time
00:16
flow is measured in different units depending on its application.
00:20
Velocity is the distance of a given fluid within a unit of time
00:25
velocity is how fast a fluid is moving
00:28
for a given flow rate. It is disproportional to the pipe radius,
00:33
flow is equivalent to the velocity of the water
00:36
multiplied by the radius of the pipe squared,
00:39
the smaller the pipe, the greater the velocity at the same flow rate.
00:44
It is important to note that low velocities can result in sediment deposits.
00:48
While changes in velocity can lift and release these deposits
00:53
flow moving through smooth unobstructed pipework will move at
00:56
a constant velocity and is known as laminar flow
01:00
head loss is the combining of energy losses within a pipe such
01:03
as frictional contact with the pipe wall or bends in the pipe
01:07
flow that is disrupted by bends or roughness of a pipe wall is called turbulent flow
01:13
losses, increase velocities and flow rates requiring more energy to overcome
01:19
losses are usually measured per distance
01:22
in WS pro.
01:23
The Darcy Weisbach
01:24
equation is used to calculate head loss
01:27
in water networks.
01:29
A hydraulic transient refers to pressure changing with time
01:32
and typically reflects rapid or unexpected changes in pressure
01:37
in the water industry. It is often referred to as a surge or water hammerer.
00:03
Before modeling water supply networks,
00:05
you must have a basic understanding of
00:07
the terminology used when discussing water pressure
00:10
flow is a unit of volume moving past a certain point within a unit of time
00:16
flow is measured in different units depending on its application.
00:20
Velocity is the distance of a given fluid within a unit of time
00:25
velocity is how fast a fluid is moving
00:28
for a given flow rate. It is disproportional to the pipe radius,
00:33
flow is equivalent to the velocity of the water
00:36
multiplied by the radius of the pipe squared,
00:39
the smaller the pipe, the greater the velocity at the same flow rate.
00:44
It is important to note that low velocities can result in sediment deposits.
00:48
While changes in velocity can lift and release these deposits
00:53
flow moving through smooth unobstructed pipework will move at
00:56
a constant velocity and is known as laminar flow
01:00
head loss is the combining of energy losses within a pipe such
01:03
as frictional contact with the pipe wall or bends in the pipe
01:07
flow that is disrupted by bends or roughness of a pipe wall is called turbulent flow
01:13
losses, increase velocities and flow rates requiring more energy to overcome
01:19
losses are usually measured per distance
01:22
in WS pro.
01:23
The Darcy Weisbach
01:24
equation is used to calculate head loss
01:27
in water networks.
01:29
A hydraulic transient refers to pressure changing with time
01:32
and typically reflects rapid or unexpected changes in pressure
01:37
in the water industry. It is often referred to as a surge or water hammerer.
Video quiz
Before modeling water supply networks, you must have a basic understanding of the terminology used when discussing water flow and velocity.
- Pressure Flow — a unit of volume moving past a certain point within a unit of time. Flow is measured in different units, depending upon its application.
- Velocity — the distance of a given fluid within a unit of time, or how fast a fluid is moving.
- Flow — equivalent to the velocity of the water multiplied by the radius of the pipe squared. The smaller the pipe, the greater the velocity at the same flowrate.
- Low velocities can result in sediment deposits, while changes in velocity can lift and release these deposits.
- Flow moving through smooth, unobstructed pipework will move at a constant velocity and is known as laminar flow.
- Headloss — the combination of energy losses within a pipe, such as frictional contact with the pipe wall or bends in the pipe.
- Turbulent flow — flow that is disrupted by bends or roughness of a pipe wall.
- Losses — increase velocities and flowrates, requiring more energy to overcome. Losses are usually measured per distance. In WS Pro, the Darcy-Weisbach equation is used to calculate headloss.
- Hydraulic transient (a.k.a. surge, water hammer) — in water networks, refers to pressure changing with time and typically reflects rapid or unexpected changes in pressure.
