Jet Engine Fundamentals and Operations

What is the Difference Between Principle - Principle of Operation?

Brayton Cycle

The continuous combustion cycle.

How Does Engine Thrust Vary?

Low temperature gives greater thrust.

Which Statement is True?

At lower engine speeds...

Static Thrust is Developed

Aircraft on the ground and stationary.

The Fan Bypass Ratio (BPR)

The mass ratio of air that passes...

P2 and P7 Sensors are Pickups for

Inlet and outer pressures.

Thrust

Increases with an increase in speed.

EPR (Engine Pressure Ratio) is

The main parameter that shows the thrust produced.

Compressor Inlet Screens

For protection against Foreign Object Debris (FOD).

Intakes are Designed to

Decelerate the free air stream.

What is the Shape of a Jet Engine Air Intake?

Divergent

Compressor Stall

Is the airflow separation due to the angle of attack.

Can Stall Appear During Engine Operation?

Yes, in case of FOD ingestion.

What Purpose Does a Diffuser Have?

To decrease the speed...

What Blades May Be Balanced?

Fan blades only.

On What Combustion System Divider

We have duplex nozzles.

Swirl Vanes in Combustion

Provide proper mixing of air and fuel.

What Factor is Important for Combustion?

The air increase.

What is Meant by Shrouded?

The turbine blades are shaped...

Across the Turbine Stages There Is

A general temperature drop.

Maximum Practical Angle Throughout

More than 90 and less than 180 degrees.

More NOx (Nitrogen Oxides) are Created When the Temperature is

Higher

Velocity of Subsonic Flow When Convergent

Increases

Function of the Exhaust Cone

To straighten and collect the exhaust gases.

Bearing Seal Failure

Leads to high oil consumption.

Most Beneficial Failure of Hydraulic

Sprayed directly on the bearing.

Oil Picks Up the Most Heat From

The turbine bearing.

What Will Result From a Blocked Oil Filter?

Reduced oil flow rate.

EEC (Electronic Engine Control) is Cooled Down By

Convection

Carbon Forming on Fuel Spray Nozzles

Changes the fuel spray pattern.

In Hydromechanical/Electronic Fuel Control

Filter clogging can occur.

At Maximum Engine Speed, Secondary Fuel Flow is

Approximately 90% of the total fuel flow.

Fuel Pumps are Designed as

Low and high pressure positive displacement pumps.

HPT (High-Pressure Turbine) IGV (Inlet Guide Vanes) are Cooled By

The air from the LPC (Low-Pressure Compressor).

When Bleed Air is On, Engine

EGT (Exhaust Gas Temperature) increases.

In What Zone is the EEC Located?

Zone 1

Great Caution Should Be Taken When Working with the EEC Because

Compounds in the unit may be hazardous.

Why Do Turbine Engines Need Ignition Systems?

For high altitude and low temperature starts.

Thrust in High Bypass Turbofan Engines is Indicated By

N1 (Low-Pressure Turbine) RPM or EPR (Engine Pressure Ratio).

Oil Pressure Indication

The absolute pressure in the oil system.

What Power is Required for the EGT Gauge?

115 VAC

For EGT Indication We Have

Many thermocouples.

Water Injection Increases

Higher density of air.

Some Older Aircraft Use

Water injection to increase thrust.

On Warm Days Thrust is Reduced Due to

Lower air density.

Afterburning is Used to

Increase thrust.

Propeller Controls for Flight

Alpha range

Reduction Gear in Helicopters

Reduces the engine speed by approximately 100 times.

When APU (Auxiliary Power Unit) Ignition Plug

APU start-cut off at 95%.

What is a Dual Loop Fire Detection System?

For warning indication, both loops shall detect a fire.

The Control Logic for Fire Detection

Fire Detect Control Unit

Running Clearance on a Turbine

Can cause temperature loss.

Where Can You Find Information About Turbine Blade Installation?

Rear face, fir-tree section.

What is Silica Gel Used For?

It is a dehydrator meant to remove moisture.

Total Pressure

Dynamic + Static pressure

Intake Air Turbulence

Decreases the efficiency of the compressor.

Defined Compressor Stator

Stator vanes that slow and increase the pressure of the airflow.

Advantage of Axial Flow Compressors

Good efficiency over a wide speed range.

In Turbojet and Turbofan Engines, Combustion Occurs at

Constant pressure.