Turbine Quiz

Turboprop

A gas turbine engine driving a propeller, achieving high propulsive efficiency, particularly at low speeds.

Turbofan

An engine utilizing bypass airflow with a front fan, enhancing propulsive efficiency and providing better performance at low speeds.

Turbojet

An engine with straight-through airflow enabling small air mass to achieve large acceleration, characterized by low thrust at low speeds but improved performance at high altitudes.

Turboshaft

Similar to turboprop engines, used primarily in helicopters and auxiliary power units, providing power to rotors rather than forward thrust.

Centrifugal Compressor

A compressor that accelerates air to add velocity but does not significantly increase pressure, known for being simple and robust.

Axial Compressor

A compressor where air flows front to back, achieving high compression ratios and mass airflow but can be complex and expensive.

Combustion Chamber

The area within the engine where fuel and air mix and combust; types include can, annular, and can-annular.

Blade Stall

Occurs when air hits a blade at the wrong angle, resulting in incorrect angle of attack and loss of efficiency.

Impulse Turbine Blade

A blade designed to change the direction of gas flow using Newton's third law, maximizing efficiency.

Reactive Turbine Blade

A blade that uses acceleration of gases in a reactive manner to enhance performance and efficiency.

Cold Section

The part of a gas turbine engine where low rpm and thrust are maintained in 'unspooled' states.

Hot Section

The section of a gas turbine engine where combustion occurs, operating at high temperatures to extract energy for work.

Turbine Creep

Permanent deformation of turbine blade materials caused by high stresses at temperatures below yield strength.

Bypass Ratio

The ratio of mass airflow bypassing the core engine compared to airflow through the core in a turbofan engine.

Thrust Specific Fuel Consumption (TSFC)

A measure of the fuel efficiency of an engine design, indicating fuel consumed per unit of thrust produced.

Ram Pressure

The pressure increase resulting from the forward speed of an aircraft, augmenting the engine's thrust.

Secondary Air in Combustion

Air introduced into the combustion chamber for cooling purposes, supporting stable combustion without combustion instability.

Compressor Bleed Air

Air extracted from the compressor section used for cooling turbine blades and maintaining engine performance under high-temperature conditions.

Impulse-Reaction Turbines

Turbine designs that combine impulse and reaction mechanisms for maximizing efficiency across various operational states.