Dynamic Pressure

Dynamic pressure is the component of fluid pressure representing the fluid kinetic energy

Dynamic pressure is a defined property of a moving flow of gas or liquid and can be expressed as

pd = 1/2 ρ v2         (1)

where

pd = dynamic pressure (Pa)

ρ = density of fluid (kg/m3)

v = velocity (m/s)

Dynamic Pressure Calculator

The calculator below can be used to calculate the dynamic pressure generated by a moving fluid. The calculator is generic and both SI and Imperial units can be used.

The default values below are for water with density of 1000 kg/m3.

ρ - density of fluid (kg/m3, lbm/ft3)

v - velocity (m/s, ft/s)

SI-units Imperial units

Some common densities at atmospheric pressure:

  • Water - 0oC - 1000 kg/m3
  • Water - 32oF - 62.4 lbm/ft3
  • Air - 20oC - 1.2 kg/m3
  • Air - 59oF - 0.0765 lbm/ft3

Example - The Dynamic Pressure in a Water Flow

The dynamic pressure in water with - temperature 20oC - density 1000 kg/m3 - velocity 5 m/s - can be calculated as

 pd = 1/2 (1000 kg/m3) (5 m/s)2

    = 12500 Pa

    = 12.5 kPa

Example - The Force acting on a Wall by a Hurricane

The dynamic pressure in a hurricane with - temperature 20oC - density 1.2 kg/m3 - velocity 37 m/s - can be calculated as

 pd = 1/2 (1.2 kg/m3) (37 m/s)2

    = 821 Pa (N/m2)

The force acting on a wall with area A = 10 m2 can be calculated as

F = pd A

  = (821 N/m2) (10 m2)

  = 8210 N

  = 8.2 kN

Related Topics

  • Fluid Mechanics - The study of fluids - liquids and gases. Involves various properties of the fluid, such as velocity, pressure, density and temperature, as functions of space and time.

Related Documents

  • Beaufort Wind Scale - The Beaufort description and observation of wind and wind velocity
  • Air Curtains and Air Screens - Air curtains or air screens in open doorways are used to keep acceptable indoor comfort in buildings
  • Sizing Ducts - The ductwork of ventilation systems are often sized with either the Velocity, the Constant Pressure Loss (or Equal Friction Loss) - or the Static Pressure Recovery Methods
  • Pitot Tubes - Pitot tubes can be used to indicate fluid flow velocity by measuring the difference between the static and dynamic pressures in fluids

Tag Search

  • en: dynamic pressure velocity pa psi
  • es: presión dinámica pa velocidad psi
  • de: Staudruckgeschwindigkeit pa psi

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