Fluid Stats Flashcards
Pressure in a fluid at rest
The normal force per unit area exerted on a plane surface immersed in a fluid and is created by bombardment of the surface with the fluid molecules.
“basic” equation for pressure
dp/ds=-ρgcosΘ (s being length of the cylinder (it’s in a cylinder))
Pascal’s law
Pressure at a point in a fluid at rest, or in motion, is independent of direction as long as there are no shearing stresses present.
pz=py=ps
In a fluid under gravity, pressure ……. with increase in depth
P=Patm+ρgh
Gauge pressure
Pressure measured with respect to atmospheric pressure
pguage=ρgh=γh
Equation for pressure head
h=pguage/ρg
What actually is a piezometer tube Manometer?
A tube which is attached to the top of a vessel containing fluid at issue higher than the atmosphere
What facts about pressure are important for piezometer tub Manometers?
For a given fluid, pressure in a given horizontal plane is the same everywhere.
In a fluid under gravity, pressure increases with increase in depth.
In piezometer tube Manometers, pressure measured is relative to……… Hence it is ……..
…… Atmospheric……. Guage pressure.
p₁=ρgh₁=γh₁
p₁=pₐ
What does the U tube do?
Measure pressure of liquids and gases
What’s the U tube filled with?
Manometric fluid
Equation for measuring pressure in U tube
if liquid pₐ=γmanh₂-γh₁
or if gas pₐ=γmanh₂
Equation for inclined tube Manometer
pa-pb=γmanl₂sinθ
