Computing Dynamic Pressure (Q)
DynamicPressure = 0.5 * DensityAir * Velocity2
Dynamic Pressure (Standard/US): lb/ft2 or pounds per square foot (psf)
Dynamic Pressure (Metric/SI): Pascals
Air Density (Standard/US): Slugs/ft3
Air Density (Metric/SI): kg/m3
Velocity (Standard/US): feet/sec (fps)
Velocity (Metric/SI): meters/sec
A F-22 Raptor is supercruising at Mach 1.7 at 40,000 feet. What is the Dynamic Pressure at that speed/altitude combination?
According to Glenn Research Center’s AtmosModeler Simulator (LINK), that speed is 1,806 km/hr (501.66 m/sec) and the air density at that altitude is 0.3 kg/m3.
The equation becomes:
0.5 * 0.3 * 501.662 = 37,749.41 pascals