Lesson 2: Principles of Hydrostatics Flashcards
It is the force per unit area exerted by a liquid or gas on a body or surface, with the force acting at right angles to the surface uniformly in all directions.
Pressure
The ____________ states that “the pressure or intensity of pressure at a point in a static fluid is equal in all direction”.
Pascal’s law
pressure above or below the atmosphere and can be measured by pressure gauges or manometers
Gauge pressure
pressure at any point on the earth’s surface from the weight of the air above it
Atmospheric pressure
pressure above absolute zero (vacuum)
Absolute pressure
in any homogenous fluid at rest, difference in pressure between any two points is __________ to the product of the unit weight of the fluid and the difference in elevation of the points.
p2-p1=yh
equal
in any homogenous fluid at rest, the pressures at all points along the same horizontal plane are _________.
equal
This means that the pressure at any depth h below a continuous free fluid surface at rest is equal to the product of the _____________ of fluid and the depth h.
unit weight
the height of column of homogenous fluid of unit weight y that will produce an intensity of pressure p.
pressure head
Types of Manometer
It is a simple and inexpensive device of measuring pressure and pressure difference. It is usually bent to form a U-tube and filled with liquid of known specific gravity. The surface of the liquid will move in proportion to changes of pressure.
Manometer
Types of Manometer
It is the simplest form of manometer which is tapped into the wall of pressure conduit for purpose of measuring pressure. Though effective in many purposes, piezometer is not practical to use in lighter liquids with large pressure and cannot be used to measure gas pressure
Piezometer
Types of Manometer
It is a tube bent into a U-shape to contain one or more fluids of different specific gravities. It is used to measure pressure.
Open manometer
Types of Manometer
It cannot measure pressure but can measure pressure difference. Frequently in hydraulic problems, difference in pressure is more useful information than the pressure itself.
Differential manometer
