Aerodynamics

Dasika Sunder

SomeFundamentalAerodynamicVariables

AerodynamicsIntroduction

Dasika Sunder

December 12, 2015

Aerodynamics

Dasika Sunder

SomeFundamentalAerodynamicVariables

Outline

1 Some Fundamental Aerodynamic Variables

Aerodynamics

Dasika Sunder

SomeFundamentalAerodynamicVariables

Pressure

Consider a surface immersed in a fluid. The surface can be areal, solid surface such as the wall of a duct or the surface of abody; it can also be a free surface which we simply imaginedrawn somewhere in the middle of a fluid.Pressure is the normal force per unit area exerted on a surfacedue to the time rate of change of momentum of the gasmolecules impacting on (or crossing) that surface.Therefore pressure at a point is defined as:

P =dF

dA

Aerodynamics

Dasika Sunder

SomeFundamentalAerodynamicVariables

Density

Density is defined as the mass per unit volume. Thereforedensity at point is defined as:

ρ =dm

dV