Aerodynamic Force

Question 1

what is aerodynamic force?

Answer 1

any force generated as a result of a solid body bing placed in a moving airstream ( or that body being caused to move through stationary air)

stems primarily from the distribution of pressure around the body and to a larger extent, friction between body and the air.

Question 2

what is Bernoulli’s theorem?

Answer 2

In the streamline flow of an ideal fluid,

the sum of all the energies will remain constant

Question 3

Bernoulli’s principle can be stated as what?

Answer 3

Dynamic pressure + static pressure = total pressure

Question 4

Bernoulli principle is accurate to what speed?

Answer 4

250kts

Question 5

above the max speed, we can apply the principle to streamline airflows around aerofoils and state what?

Answer 5

• if the speed of airflow increase air gains dynamic energy and static pressure is reduced
• if the speed of airflow is decreased, the air loses dynamic energy and static pressure is increased..

Question 6

Bernoulli’s principle applies to what?

Answer 6

streamline flow of air.

if the shape of the body causes the airflow to change direction abruptly or sharply, streamline flow breaks down and becomes turbulent with unpredictable eddies, rotor and mixing within the flow.

principle can’t be applied to turbulent flow.

Question 7

how does Bernoulli’s theorem (venturi effect) work?

Answer 7

as air flows into a venturi, it encounters restriction of the throat to allow severe amounts of air to pass through the restriction, the flow speed then increases.

and then Bernoulli’s principle states static pressure in the throat reduces.

after passing the throat, the flow gradually reduces to the freestream value and so static pressure rises back to freestream value.

Question 8

air in the throat of the venturi isn’t what?

Answer 8

compressed, streamlines being drawn closer together indicates increased flow speed.

Question 9

considering aerofoil and streamline flow around resembling venture flow. how are they similar?

Answer 9

behaves in the same way as with aerofoil forming one half of the venturi and the freestream above the following upper part of the system.

Question 10

air moving over upper surface encounter of aerofoil experiences what?

Answer 10

a restriction between aerofoil and unaffected freestream air.

like venturi flow speed increases and static pressure decrease up to throat from then its the opposite.

Question 11

is the air below an aerofoil affected by the venturi effect?

Answer 11

no which means it creates a forced called total reaction.