Air Density

Atkinson Resistance
... English units) is pressure drop (pounds per square foot), is the air density in the duct (pounds per cubic foot), is the standard air density (0.075 pound per cubic foot), is the resistance (atkinson ... is defined as the resistance of an airway which, when air flows along it at a rate of 1,000 cubic feet per second, causes a pressure drop of one pound-force per square foot ... pressure drop as where is pressure drop, is the density of the fluid in question (water, air, oil etc.), is the Fanning friction factor, is the length of the duct, is the perimeter of the duct, is the area of the ...

Max Q
... Dynamic pressure, q, is defined mathematically as where ρ is the local air density, and v is the vehicle's velocity ... into space, dynamic pressure is zero at lift-off, when the air density ρ is high but the vehicle's speed v = 0 zero outside the atmosphere, where the speed v is ... words, below max Q, the effect of the vehicle acceleration overcomes the decrease in air density so as to create more dynamic pressure (opposing kinetic energy ...

Superchargers - Aircraft - Altitude Effects
... As an aircraft climbs to higher altitude, air pressure and air density decreases ... The output of a piston engine drops because of the reduction in the mass of air that can be drawn into the engine ... For example, the air density at 30,000 ft (9,100 m) is 1⁄3 of that at sea level, thus only 1⁄3 of the amount of air can be drawn into the cylinder, with enough oxygen to provide efficient combustion for ...

Hot And High
... In aviation, hot and high is a condition of low air density due to high ambient temperature and high airport elevation ... Air density decreases with increasing temperature and altitude ... Lower air density reduces the amount of lift generated by the wings or the rotors of an aircraft, which may hamper an aircraft's performance and hence its ability to operate safely ...