Impact pressure

In compressible fluid dynamics, impact pressure (dynamic pressure) is the difference between total pressure (also known as pitot pressure or stagnation pressure) and static pressure.^[1][2] In aerodynamics notation, this quantity is denoted as ${\displaystyle q_{c}}$ or ${\displaystyle Q_{c}}$.

When input to an airspeed indicator, impact pressure is used to provide a calibrated airspeed reading. An air data computer with inputs of pitot and static pressures is able to provide a Mach number and, if static temperature is known, true airspeed.^{[citation needed]}

Some authors in the field of compressible flows use the term dynamic pressure or compressible dynamic pressure instead of impact pressure.^[3][4]