問題一覧
1
Newton’s 2nd law used
to calculate the amount of thrust produced by the engine
2
Thrust can be increased by increasing
increasing air mass flown to engine or gases acceleration through the engine
3
Thrust in a gas turbine engine is produced by
Compressor (increase air pressure) and Combustor (increase gases acceleration
4
The output of the engine when the aircraft in flight is called
net thrust
5
ESHP
= SHP + Jet Thrust Addition of SHP to jet thrust. 1hp=745.7
6
Propulsive efficiency
is the ability of engine to drive the aircraft in flight
7
The specific fuel consumption
thrust produced per pound of fuel consumed
8
At 400 knots Ram effect
increase
9
.... thrust increase with small increase in RPM
At higher engine speeds
10
As altitude increase air pressure (density) & temperature
decrease
11
Aircraft altitude & ambient temperature
affect the inlet air density.
12
Gas turbine engine efficiency increases at altitude
due to drag decrease
13
As temperature increase air density decrease
which negatively effect engine thrust and vice versa
14
Lower temperature gives
greater mass flow and greater thrust
15
the working cycle of the heat engine
as constant-pressure cycle
16
gas inside the combustion section of gas turbine engine
reduce from front to rear
17
Pressure in combustion chamber
virtually constant.
18
The rocket is
a non-air breathing engine means it does not use atmospheric air to support combustion
19
Pulse Jet
it has additional spring loaded valves in the air intake
20
The turbofan mixture of a
turbojet and a turboprop, literally handles a hot air mass and a cold air mass
21
......... always maintain high pressure compressor speed constant.
Governor
22
A high bypass engine is more efficient because it is similar to the
to the propeller by accelerating large mass of air at a low rate of acceleration
23
Easier starting (the small.... needs to be rotated by the starter
HP compressor only
24
..... is gas coupling with compressor.... mechanically connected.
Free turbine¬
25
......... drives the output shaft which drives propeller in turbo-prop engine and rotor in turbo-shaft engines
Free turbine
26
By pass ratio 5:1
indicates that bypass flow is five times the hot stream
27
1st digit represent the
bypass air
28
2nd digit represent to
engine core air
29
The highest air pressure
at compressor outlet