Gas Turbine Engine Fundamentals

The transfer of energy to a body by the application of a force that moves the body in the direction of the force.

The mass-flow of gases referred to is atmospheric air which is compressed and accelerated in the gas turbine engine to create useful work at the turbine wheel and ultimately, thrust. The thrust is created from either pure reaction to the flowing.

Physical principles that govern the action of mass or matter, essential for understanding the relationship of gases and the turbo-machinery within a gas turbine engine.

A measure of applied force distributed over a given area.

A measure of the amount of space occupied by a three-dimensional object.

The force exerted on a surface by the weight of the air above it.

The rate of change of position of an object over time.

The rate of change of velocity over time.

The rate of motion (how fast something is moving) without considering direction. Often measured in feet per second.

The product of an object's mass and velocity. A measure of how difficult it is to change an object's motion.

A principle stating that the total energy within a moving fluid (like air) remains constant. This energy is in the form of pressure (potential energy) and velocity (kinetic energy).

A type of engine where air is accelerated by burning fuel, creating thrust. Thrust is the force that propels the engine forward.

The force that pushes the gas turbine engine forward. It's created by the accelerating air.

The energy of motion. It's related to an object's speed and mass.

Stored energy due to an object's position or state. In a gas, it's often related to pressure.

Describes how thrust is produced by a propeller that rotates in an airplane. The propeller accelerates a large mass of air rearward with a small change in velocity.

Describes how thrust is produced by jet engines. They heat a mass of air, accelerating it rearward, which creates a reaction force pushing the engine forward.

Newton's 3rd law of motion states that for every action, there is an equal and opposite reaction. This explains how thrust is produced, as the action of accelerating air backward (e.g., by a jet engine or propeller) creates an equal and opposite reaction force that pushes the aircraft forward.

A thermodynamic cycle used in gas turbine engines where heat is added at a constant pressure, resulting in an increase in volume and temperature.

The process of increasing the pressure of air by reducing its volume, typically done in a compressor.

The process of expanding air, causing it to do work on a turbine, typically after the addition of heat.

The addition of heat energy to the air within a combustion chamber, causing an increase in temperature and volume while pressure stays relatively constant.

Occurs after combustion, where the hot, high-pressure air expands through a turbine, doing work and generating power.

The air is taken in at ambient pressure, initiating the Brayton cycle.

The air is released after going through the complete Brayton cycle.

This process takes place in a combustion chamber, where fuel is burned to release heat energy.

The part of a gas turbine engine where the expanding gases turn a turbine, generating power.

A measure of how much the air pressure has been increased as it flows through the compressor of a gas turbine engine. It's calculated by dividing the turbine discharge pressure by the compressor inlet pressure.

The power produced by a gas turbine engine when it is stationary. It's calculated by adding the shaft horsepower (SHP) to a factor related to thrust. This factor accounts for the engine's ability to generate thrust even when not moving.

The power produced by a jet engine while in flight, considering the thrust and speed of the aircraft. This is measured in horsepower.

The process of identifying various points within a gas turbine engine. These points represent different locations where pressures are measured. They help engineers track the performance and efficiency of the engine.

The amount of power delivered to the propeller shaft of the engine. It's measured in horsepower and represents the mechanical power generated by the engine.

A metric for the efficiency of a propeller in an airplane. It measures what percentage of the engine's power is actually used to propel the aircraft forward.

A fundamental law in physics that explains how a gas turbine engine creates thrust. For every action, there is an equal and opposite reaction. So when the engine expels hot air backward (action), it's propelled forward (reaction).