Chap 2 - Intakes

Question 1

Ideal intake should provide

Answer 1

Equal air distribution

Minimum loss of pressure occurring in the duct

Question 2

4 types of intake and what they are used in

Answer 2

Pitot - Passenger aircraft - subsonic
Divided - Fast jets - Subsonic
Variable throat - Fast jets. - supersonic
Bellmouth - Helicopters - low forward speed

Question 3

What is a bellmouth intake

Answer 3

Has a convergent shape = accelerates the airflow into engine with minimum pressure loss

☆Ideal compressor entry velocity of air should be at mach 0.5

Question 4

What are the 5 types of intake protection devices

Answer 4

A. Intake grills
B. Ice shield
C. Momentum separators
D. Sand filters
E. Particle separator

Question 5

What is a intake grill

Answer 5

Prevent the ingress of FOD
it is a wire grill fitted over intake

Question 6

What is the ice shield

Answer 6

Fitted in icy conditions stops ice from going down the engine intake

Question 7

Momentum separators

Answer 7

Passive device
Force the air stream to make sharp changes in direction. Therefore, water particles (due to high mass) separate from the main airstream

Question 8

Sand filter

Answer 8

Filter units with a spiral flow
Centrifugal force ensures sand passes through the extractor (outer) tube where it is extracted by the ejectors
Clean air then passes through outlet tubes into engine air intake
Valve controlled by SAND FILT-ON/OFF switch

Question 9

Particles separators

Answer 9

Swil motion - moves foreign particles away from the flow. These are then captured by a collection scroll case and directed overboard