IGNITION SYSTEM

Aircraft Electrical System

Input Circuit

Storage Circuit

Discharge Circuit

2 Igniter Plugs

Ignition Exciter

Box

Combustion Chamber

ENGINE

ECU115VAC

15-20KV

Starting/IgnitionSystemControl

ENGINE STARTING SYSTEM

AirStarterMotor

AircraftPneumatic System

StartValve

Air Source(APU, Ground Cart, Running Engine)

IGB

TGBAGB

ECU

High Pressure Rotor(HPC/HPT)

Starting/IgnitionSystemControl

Igniter Plug

THRUST REVERSER SYSTEM

Thrust reverser supply the aircraft with reverser thrust, on the ground, to decrease the distance necessary to safely stop the aircraft.

TYPES OF THRUST REVERSERS

Translating Cowl Type

TYPES OF THRUST REVERSERS

Clam Shell Type

TYPES OF THRUST REVERSERS

Turboprop Reverse Pitch

ENGINE CONTROL SYSTEM

FEEDBACK SYSTEM

ENGINE INDICATING SYSTEM

Gas Turbine Engine Nomenclature

Cold section = forward of the combustorHot section = from the combustor aftBleed air = air tapped from the compressor

for various usersDe Laval nozzle = a turbojet nozzle design

that produces higher exit velocityDiffuser = located between compressor

outlet and combustor inlet. Its function is to reduce velocity and increase pressure

Gas Turbine Engine Nomenclature

Engine Pressure Ratio (EPR) = ratio of turbine discharge total pressure to compressor inlet total pressure

Exhaust Gas Temperature (EGT) = temperature of exhaust gases at the turbine exhaust case

Creep = elongation of turbine rotor blades due to high torsion and heat stresses

Problem Solving

Isentropic Condition

P2/P1 = (V1/V2)k = (T2/T1)k/k-1

Isobaric Condition

V2/V1 = T2/T1

Problem Solving

Newton’s 2nd Law of MotionF = m x a =Forcem = massa = acceleration

TB = ṁ (Ve – Vo) = Basic Jet Thrustṁ = mass flow rateVe = exit velocityVo = inlet velocity

Problem Solving

Additional Thrust

Due to added fuel flow MF within the system

ΔTF = MF x VeDue to difference between exit pressure Pe

and the atmospheric pressure Po

ΔTP = Ae (Pe - Po)

MF = mass of fuelAe = cross sectional area of exit section

Problem Solving

Total Jet Thrust, T = TB + ΔTF + ΔTP

= Ma [ Ve (1 + F) – Vo ] + Ae (Pe – Po)

F = MF/Ma = fuel-air ratio

Mg = Ma + MF = Ma (1+F) = mass of gas

Problem Solving

Thp = T Vo / C = Thrust power

C = constant to convert unit to horsepower

TSFC = WF/T = Thrust specific fuel consumption

WF = weight of fuel

BSFC = WF/Thp = Brake specific fuel consumption

Problem Solving

1. The three basic components of the core engine

a. Inlet, compressor and turbine

b. Turbine, combustor and fan

c. Turbine, compressor and combustor

Problem Solving

2. The law of motion that states that “for every action there’s a reaction equal in magnitude but opposite in direction”

a. First law of motion

b. Second law of motion

c. Third law of motion

Problem Solving

3. The thermodynamic processes that occur in the proper sequence in Brayton cycle which explains the operation of a gas turbine engine are the following:

a. Isentropic, isochoric, isentropic, then isochoric

b. Isobaric, isentropic, isobaric, then isentropic

c. Isentropic, isobaric, isentropic, then isobaric

Problem Solving

4. Type of jet engine that can be used in outer space

a. Ramjets

b. Gas turbine engines

c. Rockets

Problem Solving

5. Which of the following parameters could increase thrust production?

a. Increase air inlet velocity

b. Decrease air exhaust velocity

c. Decrease air temperature

Problem Solving

6. Which statement is true with regards to compressors?

a. Centrifugal type of compressors has a higher total pressure ratio

b. Axial flow type of compressors has a higher pressure rise per stage

c. Centrifugal type of compressors has a larger frontal area

Problem Solving

7. The rotating part of the centrifugal flow compressor

a. Stator

b. Rotor

c. Impeller

Problem Solving

8. Which statement is true with regards to axial flow compressors?

a. The pressure increases only when it passes through the rotors

b. One compressor stage means air passes through one stator and one rotor

c. The velocity is kept constant as it passes through a compressor stage

Problem Solving

9. Which statement is true with regards to combustors?

a. Each can in a can type combustor has an igniter plug

b. All air coming from the compressor is mixed with the fuel to provide continuous combustion

c. The velocity of the air coming from the compressor is reduced to provide continuous combustion

Problem Solving

10. Which statement is true with regards to heat exchangers?

a. Air is used to cool the oil

b. Fuel heats up while the oil cools down

c. Oil heats up while the fuel cools down

Problem Solving

11. The intake of the compressor of an air-standard Brayton Cycle is 40,000 cfm at 15 psia and 90F. The compression ratio, rk = 5 and the temperature at the turbine inlet is 15 psia. Determine the net work, thermal efficiency and the mean effective pressure.

Problem Solving

12. There are required 2238kW net from a gas turbine unit for pumping of crude oil from the North Alaskan Slope. Air enters the compressor section at 99.975 kPa, 278 K, the pressure ratio rp = 10. The turbine section receives the hot gases at 1111K. Assume the closed Brayton cycle and find a) the required airflow and b) the thermal efficiency.

Problem Solving

13. The turbine section of a Brayton cycle gas turbine receives the hot compressed air at 150 psia, 2100R, expand it to 15 psia and develops a gross output of 15,000 hp. Air enters the compressor section at 15 psia, 500R. Determine a) mass of air required, lb/s, b) compressor power required, c) net power output, and, d) cycle efficiency

Problem Solving

14. A turbojet-powered airplane is at level flight at sea level with a speed of 300 mph. Air enters the engine air intake at the rate of 75 lbs per second. Burned gas leaves the engine nozzle exit at 700 mph at atmospheric pressure. Fuel-air ratio is 1:20. The engine net thrust in Newtons is….

Problem Solving

15. The mass flow rate of the air flowing inside a gas turbine engine is 100 pounds per second. If the engine is capable of producing 10,000 pounds of thrust and the airplane is flying at a speed of 75 mph, what is the velocity of the gas at the exit considering the mass of fuel as negligible.

THE END