Aerodynamic theories

Definition - ‘Force’ Definition – ‘Aerodynamic Force’ Fundamental sources of

Aerodynamic Force Pressure Distribution Shear Stress Types of Flows

Equation of Continuity Bernoulli’s Theorem / Application Flat Plate Effect

Aerodynamic TheoriesAerodynamic Theories 11

Definitions ‘Force’ ‘Aerodynamic Force’

Fundamental sources of Aerodynamic Force Pressure Distribution Shear Stress Types of Flows Equation of Continuity Bernoulli’s Theorem / Application Flat Plate Effect Conclusion



Introduction: Aerodynamics Basics

F16 pushes the F16 pushes the ground by 28000 lbs ground by 28000 lbs

and the ground and the ground pushes the a/c by pushes the a/c by

28000 lbs28000 lbs


Contact force / Surface force

Distance force / Body force


Frictional Force

Tensional Force

Air Resistance Force

Applied Force

Spring Force



Gravitational Force

Electrical Force

Magnetic Force


Vector =Magnitude + Direction

350 Kts350 KtsHeading 345°Heading 345°


Balanced force

Unbalanced force


Force exerted on a body whenever there is a

relative velocity between the body and the

air


Pressure Distribution

Shear Stress



1919Aerodynamic TheoriesAerodynamic Theories


Pressure

Density

Temperature

Flow Velocity and Streamlines


Speed and direction of gas may vary from point to point in the flow

The velocity at any fixed point B in a flowing gas is the velocity of an infinitesimally small fluid element as it sweeps through B


Steady Streamline

Two Dimensional

Three Dimensional


Flow parameters (speed, direction, pressure

variable)

May vary from point to point in the flow but

At any point are constant with respect to time

Classical Linear: More or less, streamlines follow

body contour without separation

Controlled Separated / LE Vortex Flow (at Hi

AOA) LE vortex on highly swept plan-forms, and

A strong controlled vortex (at a sharp LE) is made to produce

useful lift forceAerodynamic TheoriesAerodynamic Theories 2424



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Aerodynamic theories