Basic Turbine Engine Theory

Question 1

Newton’s third law

Answer 1

For every action there is an equal and opposite reaction

Question 2

Newton’s law relative to turbine engine

Answer 2

As turbine engine accelerates air rearwards, the engine itself is accelerated forwards.

Question 3

Boyle’s law

Answer 3

If a given mass of gas is compressed at a constant temperature, the absolute pressure is inversely proportional to its volume.

P x V = K

Question 4

Charles’ Law

Answer 4

If a gas is heated at a constant pressure, the change in volume will vary directly with the change in the absolute temperature, the change being the same for all perfect gases.

V/T = K

Question 5

Bernoulli’s theorem

Answer 5

In a streamline flow of an ideal fluid the sum of all energies must remain constant.

This principle is used by the placement of convergent and divergent ducts.

Question 6

When can air be assumed to be an ideal fluid?

Answer 6

Below 250kt, below 10,000ft

Question 7

Brayton constant pressure cycle

Answer 7

A simultaneous cycle of induction, compression, combustion, and exhaust where combustion takes place at a constant pressure.

Question 8

Four stroke combusts at a constant

Answer 8

Volume

Question 9

Turbine combusts at a constant

Answer 9

Pressure

Question 10

Changes to pressure, temperature, and velocity of the gas flow as it passes through each section of a turbine engine.

Answer 10

Temperature: Slowly increases, peaks at turbine, falls off at exhaust

Pressure: Increases linearly, peaks at the end of the compression stage, decreases in combustion chamber, falls off at the exhaust stage

Velocity: Speed is constant, varies in the turbine stage, increases at the exhaust