15.1 fundamentals

Question 1

what is energy measured in?

Answer 1

Joules

Question 2

potential energy formula

Answer 2

pe=mgh

Question 3

kinetic energy formula

Answer 3

ke=1/2mv*2

Question 4

what is newtons first law

Answer 4

law of inertia

Question 5

what is n2l

Answer 5

f=ma

Question 6

what is newtons third law

Answer 6

law of action and reaction

Question 7

what is brayton cycle

Answer 7

suck squeeze bang blow

Question 8

where does the brayton cycle apply to in engine

Answer 8

suck = intake
squeeze = compressor
expansion = bang
exhaust = blow

Question 9

what are the 4 ideal changes of state

Answer 9

isobaric
isochoric
isothermal
isentropic

Question 10

why does change of state occur in a thermal engine

Answer 10

transformation of heat energy into mechanical work and vice versa

Question 11

for a gas turbine engine - what are the only isobaric and isentropic chance of state?

Answer 11

are of importance

Question 12

what is stage 0-1 on the pressure volume diagram

Answer 12

ram or dynamic compression in the air intake

Question 13

what is stage 1-2 on the pressure volume diagram

Answer 13

mechanical compression in the compressor, driven by the gas turbine

Question 14

what is stage 2-3 on the pressure volume diagram

Answer 14

isobaric heating - increasing the volume as fuel and air is mixed and burned

Question 15

what is stage 3-4 of the pressure volume diagram

Answer 15

energy in expanded gases are turned into mechanical power

Question 16

what is stage 4-5 on pressure volume diagram

Answer 16

remaining energy provides a propulsive jet in the nozzle

Question 17

what is formula for force

Answer 17

f=ma

Question 18

what is formula for work

Answer 18

force x distance

Question 19

what is si unit for work

Answer 19

1 joule

Question 20

what is 1 joule in nm

Answer 20

1 nm

Question 21

what is formula for power

Answer 21

power = work/time
power=(fxd)/t

Question 22

what is si unit of power

Answer 22

watt

Question 23

what is 1 watt in nm

Answer 23

1w=1nm

Question 24

formula for acceleration

Answer 24

change in velocity / time

Question 25

what are the 4 different types of gas turbine engines

Answer 25

turbojet turboprop turbofan turboshaft

Question 26

pro and con of turbojet?

Answer 26

pro - very fast, simple design, small frontal area con- high fuel consumption, loud, poor performance at slow speed, limited in range and performance

Question 27

how much thrust does the fans at the front of a turbofan engine produce

Answer 27

80% thrust

Question 28

what is a spool

Answer 28

turbine driving a compressor through a shaft

Question 29

disadvantage of turbofan

Answer 29

inefficient at very high altitudes large frontal area heavier than turbojets

Question 30

what force is turboprop designed to produce

Answer 30

shaft horsepower only

Question 31

advantages of turboprop

Answer 31

very fuel efficient most efficient at mid range speed of 250-400 knots most efficient at mid range altitudes of 18000ft - 30000ft

Question 32

disadvantage of turboprop

Answer 32

limited forward airspeed gearing systems are heavy and can break down

Question 33

where is turboshaft used

Answer 33

in helicopters apu

Question 34

pros of turboshaft

Answer 34

higher power-weight ratio than piston typically smaller than piston

Question 35

disadvantage of turboshaft

Answer 35

loud gear systems connected can be complex and break down

Question 36

pros of modular engine design

Answer 36

pre-balanced fewer spare engines needed removed without disturbing the other engine sections