Why is an excess of air used in a gas turbine?

Question

Why is an excess of air used in a gas turbine?

Answer 1

Excess air is working fluid.

It absorbs heat and expands allowing energy to be extracted

from the combustion at lower temperatures.

Answer 2

A gas turbine is a rotary machine, similar in principle to a steam turbine. It consists of three main components - a compressor, a combustion chamber and a turbine. The air after being compressed into the compressor is heated either by directly burning fuel in it or by burning fuel externally in a heat exchanger. The heated air with or without products of combustion is expanded in a turbine resulting in work output, a substantial part, about two-thirds, of which is used to drive the compressor. The rest, about one-third, is available as useful work output.

Excess air is used to make sure combustion occurs properly. The more air the more power can be produced. The air also used to cool the parts as well release any unnecessary heat. Visit for more information website below

Answer 3

Excess air is required to keep the turbine-inlet temperature down to a level which will not melt the turbine.