Dynamic Pressure

on . Posted in Dynamics

Dynamic pressure, abbreviated as q or Q, also known as velocity pressure, is the amount of total pressure resulting from the media velocity.  In fluid dynamics that represents the kinetic energy of a moving fluid.  It's a measure of the pressure that a fluid in motion exerts on surfaces perpendicular to its flow direction.  Dynamic pressure is an important parameter in aerodynamics and fluid mechanics, as it helps to quantify the impact of fluid motion on objects.

The dynamic pressure increases with the square of the fluid velocity and is directly proportional to the density of the fluid.  This means that at higher velocities or in denser fluids, the dynamic pressure becomes more significant.  Dynamic pressure is a measure of the energy associated with the fluid motion and is responsible for producing forces like lift and drag on objects moving through the fluid.

In aerodynamics, dynamic pressure plays a crucial role in understanding the forces acting on an aircraft, such as lift and drag.  For example, the lift force generated by an airplane wing is often related to the dynamic pressure difference between the upper and lower surfaces of the wing.  Similarly, the drag force is influenced by the dynamic pressure acting on the front surface of the object.


Dynamic Pressure formula

\( q = \frac{ 1 }{ 2 }\; \rho \; v^2  \)     (Dynamic Pressure)

\( \rho =  2 \; q \;/\; v^2 \)

\( v =  \sqrt{ 2 \; q \;/\; \rho }  \) 

Symbol English Metric
\( q \) = dynamic pressure  \(lbf\;/\;in^2\) \( Pa \) 
\( \rho \)   (Greek symbol rho) = density of fluid \(lbm\;/\;ft^3\) \(kg\;/\;m^3\)
\( v \) = velocity of fluid \(ft\;/\;sec\) \(m\;/\;s\)


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Tags: Pressure