Dynamic Pressure
Dynamic pressure is the kinetic energy per unit volume of a fluid in movement.
Dynamic pressure is the kinetic energy of a flowing fluid  liquid or gas  per unit volume  and can be expressed as
p _{ d } = 1/2 ρ v ^{ 2 } (1)
where
p _{ d } = dynamic pressure (N/m ^{ 2 } (Pa), lb _{ f } /ft ^{ 2 } (psf))
ρ = density of fluid (kg/m ^{ 3 } , slugs /ft ^{ 3 } )
v = velocity (m/s, ft/s)
Dynamic Pressure Calculator  SI Units
The default values below are for water with density of 1000 kg/m ^{ 3 } .
 1 N/m ^{ 2 } = 1 Pa = 1.4504x10 ^{ 4 } lb _{ f } /in ^{ 2 } (psi) = 0.02089 lb _{ f } /ft ^{ 2 } (psf) = 1x10 ^{ 5 } bar = 4.03x10 ^{ 3 } in water = 0.336x10 ^{ 3 } ft water = 0.1024 mm water = 0.295x10 ^{ 3 } in mercury = 7.55x10 ^{ 3 } mm mercury = 0.1024 kp/m ^{ 2 } = 0.993x10 ^{ 5 } atm
Dynamic Pressure Calculator  Imperial Units
The default values below are for water with density of 1.940 slugs .
Some common densities at atmospheric pressure:
 Water  0 ^{ o } C  1000 kg/m ^{ 3 }
 Water  32 ^{ o } F  1.940 slugs/ft ^{ 3 }
 Air  20 ^{ o } C  1.2 kg/m ^{ 3 }
 Air  60 ^{ o } F  2.373 10 ^{ 3 } slugs/ft ^{ 3 }
Example  The Dynamic Pressure in a Water Flow
The dynamic pressure in water with  temperature 20 ^{ o } C  density 1000 kg/m ^{ 3 } and velocity 5 m/s  can be calculated as
p _{ d } = 1/2 (1000 kg/m ^{ 3 } ) (5 m/s) ^{ 2 }
= 12500 Pa
= 12.5 kPa
Example  Hurricane and Force acting on a Wall
The dynamic pressure in a hurricane with air temperature 20 ^{ o } C, density of air 1.2 kg/m ^{ 3 } and wind speed 37 m/s can be calculated as
p _{ d } = 1/2 (1.2 kg/m ^{ 3 } ) (37 m/s) ^{ 2 }
= 821 Pa (N/m ^{ 2 } )
The force acting directly on a wall with area 10 m ^{ 2 } can be calculated as
F = p _{ d } A
= (821 N/m ^{ 2 } ) (10 m ^{ 2 } )
= 8210 N
= 8.2 kN
 almost the weight of a small car.
Note!  the real force acting on the wall  or an other obstruction in the wind  is in general more complicated to calculate due to drag , turbulence and other effects.
Related Topics

Fluid Mechanics
The study of fluids  liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time.
Related Documents

Air Curtains or Air Screens
Calculate air curtains or air screens in open doorways used to keep acceptable indoor comfort in buildings. 
Beaufort's Wind Scale
The Beaufort description and observation scale for wind and wind speed. 
Distance Traveled vs. Speed and Time  Calculator and Chart
Velocity plotted in time used diagram. 
Ducts Sizing  the Velocity Reduction Method
The velocity reduction method can be used when sizing air ducts. 
Kinetic Energy
Energy possessed by an object's motion is kinetic energy. 
Pitot Tubes
Pitot tubes can be used to measure fluid flow velocities by measuring the difference between static and dynamic pressure in the flow. 
Velocity Pressure Head
Dynamic pressure or velocity head. 
Wind Load vs. Wind Speed
Wind load on surface  Wind load calculator.