mod 4

Question 1

most common propulsion system option

Answer 1

piston powered / piston propeller powered

Question 2

copmossed of a single or dual stage; which have a high compression ratio

Answer 2

centrifugal turbojet

Question 3

mutiple compressor stages with low compression ratio

Answer 3

axial flow turbojet

Question 4

derivative of axial flow turbojet with fan in front and by pass ratio

Answer 4

turbo fan

Question 5

jet engine instead of driving a fan or compression stage; it drives a shaft which rotates a gear box which drives a propeller

Answer 5

turbo prop

Question 6

shatf directly for rotary; goes in reduction gears

Answer 6

turbo shaft

Question 7

not all of the air and fuel; stoichiometric measurements are cannot be consumed; therefore theres still left in the system; burning it produces more thrust what is it?

Answer 7

afterburners

Question 8

hollowed version of axial flow; mechanism that open when theres sufficeint pressure - self sustaining; limited applications; usually at cruise

Answer 8

ram jet

Question 9

propeller powered utilize and utilizes in supersonic speed; for transonic purposes.

Answer 9

Propfan

Question 9

a supersonic version of ram jet; utilizes shockwaves

Answer 9

scram jet

Question 10

recover sufficient pressure / ram recovery

Answer 10

iNLET GEOMETRY

Question 11

poor presure recovery, reduce wetted area and weight

Answer 11

flush inlets

Question 12

subsonic and low supersonic fligths, lip - distortion and accomodation of intake air

Answer 12

pitot / normal shock inlet

Question 13

high supersonic speed

Answer 13

conical or spike or round inlet
2-d ramp inlet

Question 14

inlet for radial engine

Answer 14

naca inlet/ naca cowl

Question 15

compressing the air inside the inlet _______

Used for super sonic regimes

Answer 15

internal compression inlet

external compression inlets

Question 16

lip radius should be below ___ for subsonic

Answer 16

20 degrees

Question 17

higher overall pressure ratio = higher trust

Question 18

note on variable ramp

Answer 18

use instead of inlet cones; uses aerodynamics to control intakes

Question 19

for initial layout, initial ramp angle of___ and determine shock angle for the design mach number where the cowl lip should be positioned just aft of the shock

Answer 19

10 - 20 degrees

Question 20

throat area should be atleast____ of the engine front face area external compression inlets vs internal compression inlets

Answer 20

70 -80%

Question 21

should be design to facilitate adequate pressure increase

Answer 21

diffuser are

Question 22

higher over all pressure ratio = higher thrust

Answer 22

direct to velocity that measure your trust production

Question 23

inlet location where it ensures clean integration;

down side: causes longer inlet duct that causes boundary layer extension that causes more skin friction drag; less fuselage area

Answer 23

nose inlet location

Question 24

eliminate the need for long inlet; it also act as a scoop downside: still long; challenging for payload and alnding gear

Answer 24

chin mounted inlet

Question 25

does not use scoop mechanism; could block sucking pilot: they feel like they could be sucked by the engine

Answer 25

over the fuselage

Question 26

you can provide more storage; imbalance on efficiency when one is blocked; differen thrust output

Answer 26

under the wing over the wing (inefficient wing)

Question 27

inegrated in the structure and do not interfere the wing aerodynamics

Answer 27

wing root

Question 28

down si=de: make more wetted area good side; for light weight purposes

Answer 28

wing leading edge

Question 29

adv: we can mount in such a way it is efficient smaller inlet -separates inlet and the fuselage providing undisturbed air and very short inlet duct -reduces cabin noise -easier access to the pylon mounted pods during maintenance dis: you have pylons; more wetted area

Answer 29

podded engines

Question 30

theoretical inlet area where your engine is capable of sucking air

Answer 30

capture area; capture area gets larger becasue of its aerodynamics

Question 31

before you get the air to the engine, you have to ensure the accont of bounmdary layer; therefore the capture area should not be affected or eliminated by boundary area therefore _____ uses to avoid the boundary layer

Answer 31

boundary layer diverter

Question 32

note on pitot tube;

Answer 32

uses hook to avoid boundary layer to not need to correct the IAS. also put in the very front