Drag (Chapter 7)

Question 1

Laminar flow changes to turbulent flow at the……………point

Answer 1

Transition point

Question 2

The transition point shall never be:

Answer 2

Aft of the maximum thickness of the aerofoil

Question 3

Laminar air flow has a ___________ velocity gradient

Answer 3

shallow

Question 4

Turbulent airflow has a _____________ velocity gradient

Answer 4

Steep

Question 5

The lowest pressure of an aerofoil is on the _______ of the aerofoil

Answer 5

Top

Question 6

The separation point shall move __________ with an increase in AoA

Answer 6

Forwards

Question 7

Laminar flow is:

Answer 7

Low Energy
Thin layer (1-2mm)
Predictable airflow

Question 8

Turbulent airflow is:

Answer 8

High energy
Thick layer (2-3cm)
Mixed airflow

Question 9

Reynolds Number is:

Answer 9

A dimensionless number which states the type of airflow (<500,00 is laminar) (>10,000,000 is turbulent)

Question 10

Skin Friction drag

Answer 10

The drag which occurs within the boundary layer of the aerofoil

Question 11

Form Drag

Answer 11

The drag which is created due to the pressure differential behind the trailing edge of the aerofoil