An interactive Java applet for this slide is now available. You can study the effects of burner performance on thrust and fuel flow. Most modern passenger and military aircraft are powered by gas turbine engines, which are also called jet engines. There are several different types of jet engines, but all jet engines have some parts in common.
All jet engines have a combustor or burner in which the air and fuel are mixed and burned.
The burning occurs at a higher pressure than free stream because of the action of the compressor. The pressure in the burner remains nearly constant during burning, decreasing by only 1 to 2 per cent. Comparing the compressor and power turbine thermodynamics slides, we cannot simply relate the temperature change in the burner to the pressure change because the physical processes are different. In the compressor and turbine, no heat enters the domain. Under those conditions the pressure and temperature are related.