How does a gas turbine engine (i.e., an aircraft engine) work?
A gas turbine uses energy stored in pressurized or rapidly moving gas to do work on a rotating mechanism. This rotary work can then be used to propel a vehicle or to generate electricity. Whether the gas is pressurized or rapidly moving doesn’t really matter much. What is important is that the gas tends to flow from one region to another through a series of turbine blades. If the gas is pressurized, it is propelled through the blades by the unbalanced pressures (gases always accelerate toward lower pressure). If the gas is rapidly moving, it flows through the blades because of inertia.
As the gas flows through the turbine blades, it flows over and under each blade. The blades are shaped so that the gas goes faster over each blade than under each blade, and an imbalance of pressures results as a consequence of Bernoulli’s effect. Each turbine blade acts like the wing of an airplane and experiences a lift force. This lift force pushes on each blade and twists the turbine around and around. The turbine blades effectively fly through the flowing gas stream and extract energy from it. The blades and turbine gain energy while the gas stream loses energy. The gas leaves the turbine at a lower pressure and/or speed than it had when it arrived.