Gas Turbine Engine Oil System

Questions and Answers

What type of warning light is commonly used in oil pressure systems of turbine engines?

Temperature warning light

High-pressure warning light

Low-oil pressure warning light (correct)

Pressure gauge alert light

Where is the turbine engine pressure gauge typically connected in the oil system?

At the engine bearings

At the oil temperature sensor

Before the oil cooler

Downstream of the main oil filter (correct)

When does the low oil pressure warning light extinguish during the engine start sequence?

When electrical power is turned on

When the oil temperature rises

When oil pressure exceeds the low limit (correct)

When the engine stops running

Which component is positioned between the oil temperature sensor and the engine bearings?

Oil cooler Signup and view all the answers

What electronic display system do modern aircraft use for engine oil indication?

ECAM or EICAS Signup and view all the answers

Which of the following is measured by the oil filter differential pressure switch?

Oil filtration performance Signup and view all the answers

What happens to the low oil pressure light when the engine is not running and electrical power is on?

It illuminates Signup and view all the answers

Where is the oil temperature sensor located in relation to the oil system components?

After the oil passes through the filter Signup and view all the answers

What is the primary purpose of continuously supplying cooling air into the turbine disc cavities?

To prevent overheating and thermal expansion Signup and view all the answers

How is the flow and pressure of the cooling air in the turbine disc cavities managed?

By the interstage seals Signup and view all the answers

Where does the cooling air go after flowing over the turbine disc faces?

It is discharged into the main gas stream Signup and view all the answers

What is a significant role of the external cooling system in the engine bay or pod?

To purge flammable vapours Signup and view all the answers

Why is it important to minimize the airflow around the engine?

To reduce engine drag Signup and view all the answers

What is a primary characteristic of simplex fuel nozzles?

They incorporate a single spray pattern. Signup and view all the answers

What is the role of the internal check valve in a simplex fuel nozzle?

To prevent fuel dribbling after shutdown. Signup and view all the answers

What happens if hot mainstream gas is ingested into the turbine disc cavities?

It causes thermal expansion and fatigue Signup and view all the answers

At which engine operational conditions are simplex nozzles most effective?

High pressure and high RPM. Signup and view all the answers

What controls the airflow over the turbine disc faces?

The interstage seals Signup and view all the answers

What is the effect of excess hot gas ingestion on turbine discs?

It leads to unwanted thermal stresses Signup and view all the answers

What defines duplex fuel nozzles compared to simplex fuel nozzles?

They have two separate fuel flows. Signup and view all the answers

What is the function of the primary flow in duplex fuel nozzles?

To facilitate engine start-up to idle. Signup and view all the answers

Why are simplex nozzles considered unsatisfactory at low pressures?

They do not atomize fuel effectively. Signup and view all the answers

Which configuration is utilized by duplex fuel nozzles?

Dual line with primary and secondary flow. Signup and view all the answers

How does the simplex design impart swirling motion to the fuel?

By incorporating an internally fluted spin chamber. Signup and view all the answers

What happens to the main metering valve when Px air contracts the acceleration bellows?

It moves to open. Signup and view all the answers

Which force is greater causing the flyweights to move outwards when the power lever is retarded?

Flyweight force due to high engine rpm. Signup and view all the answers

What effect does the opening of the governor valve have on Py air?

It allows Py air to be bled off. Signup and view all the answers

What role does the bypass valve play in the fuel pump system?

It returns excess fuel back to the pump inlet. Signup and view all the answers

What primarily controls the metering valve position in this system?

Engine rpm. Signup and view all the answers

When the governor rod moves up due to Px air expansion, what is the subsequent action of the main metering valve?

It starts to close. Signup and view all the answers

Which of the following parameters is considered secondary in controlling the metering valve?

Compressor discharge pressure. Signup and view all the answers

What happens to the deceleration bellows as engine speed slows?

It moves downwards. Signup and view all the answers

What type of seal is used between the mating faces of components in the flexible elbow system?

Crush type seal Signup and view all the answers

What is the purpose of the V-band type clamp in the flexible elbow assembly?

To tightly clamp the joints together Signup and view all the answers

What do temperature compensators allow ducts to do in response to thermal expansion?

Grow and expand Signup and view all the answers

Where are one-way check valves typically located within the system?

In the ducts from pressure sources Signup and view all the answers

What issue do temperature compensators specifically address in larger aircraft?

Thermal expansion of ducting Signup and view all the answers

Which of the following best describes the insulation provided in the flexible elbow system?

It is lock-wired around the bare metal Signup and view all the answers

What function does the check valve serve in relation to the APU?

It prevents the loss of manifold pressure Signup and view all the answers

Which component is NOT mentioned as a source for airflow controlled by check valves?

Main engine Signup and view all the answers

Study Notes

Oil System Indication

Oil system incorporates gauges for pressure, quantity, low pressure, filter differential, and temperature.
Oil pressure gauge is located downstream of the main oil filter for accurate engine pressure indication.
Low oil pressure warning light illuminates when electrical power is on, turning off once oil pressure exceeds the low limit.
Oil temperature sensor is placed in the pressure line before reaching engine bearings and after filters and coolers.

ECAM/EICAS Engine Oil Indication

Modern aircraft display engine oil indication electronically via ECAM or EICAS in the cockpit.
Governor mechanisms utilize air pressure to maintain stable fuel flow and engine RPM.
Changes in engine RPM modify governor and metering valve positions, impacting fuel flow.
Simplex fuel nozzles provide a single spray pattern with an internal check valve to prevent fuel dribble after shutdown.
Duplex fuel nozzles feature primary and secondary flows, with distinct orifice sizes for varying engine operations.

Pre-Swirl Nozzle Cooling System

Hot gas ingestion can cause turbine disc overheating and fatigue.
Cooling air is supplied to turbine disc cavities to prevent hot gas entry, with flow controlled by interstage seals.

Turbine Disc Cooling

Cooling air flows through annular spaces between turbine discs and is expelled into the main gas stream after heat absorption.
Airflow management across disc faces is regulated by interstage seals to optimize cooling efficiency.

External Cooling

Engine bay cooled by external atmospheric air, purging flammable vapors while minimizing drag.
Ventilation systems are designed to efficiently manage temperature around the engine components.

Crush Type Seal and Insulation

Crush seals are used between mating component faces, secured with V-band clamps for tight connections.
Insulation blankets cover joints to prevent heat loss and enhance thermal efficiency.

Temperature Compensators

Temperature compensators are employed to allow duct expansion due to temperature variations.
Slip joints in compensators accommodate duct growth without structural issues.

Check Valves

One-way check valves regulate airflow from sources like APU and external connections.
Check valves prevent loss of manifold pressure when the respective systems are inactive.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the oil system in gas turbine engines. This quiz covers various indicators and their functions, including oil pressure, quantity, and temperature gauges. Essential for understanding engine lubrication systems.