In flight mechanics, the “equation of state” refers to a mathematical relationship that describes the thermodynamic state of a fluid (usually air) under specific conditions. This relationship helps to relate the fundamental properties of the fluid, such as pressure, density, temperature, and specific volume. In the context of aviation and aerodynamics, the equation of state is essential for understanding the behavior of the air through which an aircraft flies.
p=ρ * 287 * temperature”
P is the pressure of the gas,
ρ=density
The constant “287” is the specific gas constant for dry air and has a value of approximately 287 J/(kg·K).