Dynamic pressure
In fluid dynamics dynamic pressure depends on density and velocity of the fluid.
It is defined by the following equation (with q standing for dynamic pressure or "velocity pressure"):
- [math]\displaystyle{ q \ = \ \frac{1}{2} \rho v^2 }[/math]
where (using SI units):
- [math]\displaystyle{ q }[/math] = dynamic pressure in pascals
- [math]\displaystyle{ \rho }[/math] = fluid density in kg/m3 (such as the density of air)
- [math]\displaystyle{ v }[/math] = fluid velocity in m/s
Physical meaning
Dynamic pressure is closely related to the kinetic energy of a fluid particle, since both quantities are proportional to the particle's mass (through the density, in the case of dynamic pressure) and square of the velocity. Dynamic pressure is in fact one of the terms of Bernoulli's equation, which is essentially an equation of energy conservation for a fluid in motion.
Dynamic Pressure Media
A flow of air through a venturi meter, showing the columns connected in a U-shape (a manometer) and partially filled with water. The meter is "read" as a differential pressure head in cm or inches of water and is equivalent to the difference in velocity head.
Related pages
Other websites
- Definition of dynamic pressure on Eric Weisstein's World of Science
