P 0 = atmospheric pressure at sea level in pascals K = non-dimensional heat capacity ratio (1.4 for air, constant)Īlternatively, considering for example a spacecraft during launch and using the formula for the air density as a function of altitude (only valid below the tropopause), the dynamic pressure associated with the spacecraft can be expressed as: Ρ = density in kg/m 3 R = specific gas constant (287.05 J/(kg

If the fluid in question can be considered an ideal gas (which is generally the case for air), the dynamic pressure can be expressed as a function of fluid pressure and Mach number. The point of maximum aerodynamic load is often referred to as max Q and it is a critical parameter, for example, for spacecraft during launch. Therefore, by looking at the variation of q during flight, it is possible to determine how the stress will vary and in particular when it will reach its maximum value. stress within a structure subject to aerodynamic forces) experienced by an aircraft traveling at speed v is proportional to the air density and square of v, i.e. 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.Īnother important aspect of dynamic pressure is that, as dimensional analysis shows, the aerodynamic stress (i.e. density of air)ĭynamic 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. Safe Weighing Range Ensures Accurate Results

Dynamic ram pressure