What are the four fundamental variables in aerodynamics?
The four fundamental quantities in language of aerodynamics are Pressure, Density, Temperature and Velocity. Let us look at each one.
Pressure is defined as a point property. It varies from one point to another on the surface of the object. (or) Pressure is defined as force per unit area, e.g., newton’s/meter2
In fact, pressure is usually defined at a point on the surface can vary from one point to another point. we can use the language of differential calculus to see this more clearly.
Consider a point B in a volume of gas. Let
dA = incremental area around B
df = force in perpendicular
then the pressure at point B in the gas define as
Pressure is a one of most fundamental and important variable in aerodynamics. Common units of pressure are Newton/meter2, dynes/centimetre2, pound/foot2 and atmospheres. Abbreviations for this quantities are N/m2 , dyn/cm2, lb/ft2, and atm, respectively.
In the next article we will discuss about the Density