How Gas Turbines Work – A Brief Overview

From racing cars to motorcycles and buses – every single machine is run using gas turbines these days. With high power to weight ratios and very good power outputs, these gas turbines are slowly taking over the entire sector of engines with their countless advantages and trivial disadvantages.

While gathering information on gas turbines, it is very essential to know how they work. This is the key to understanding their prevalence in the market, as only by learning the intricate details can you actually understand the advantages of using a gas turbine over a conventional turbine, like the steam turbine.

Some Basic Know How - The Mechanism Behind A Gas Turbine

Gas turbines are basically cyclic heat engines that are extremely efficient among the available engines. Their efficiency is normally because of the higher combustion temperature involved in them. 

Gas turbines are engines that use isentropically compressed air in order to aid combustion. Combustion in gas turbines normally occurs at a constant pressure, thanks to the isentropically compressed air. Expansion in gas turbines normally occurs isentropically too, taking the engine back to the normal starting pressure condition.

In the compression part of the procedure, the delivery temperature in the compressor is very high for the overall pressure ratio given. During non-isentropic expansion too, the pressure in the engine is very high and thus the expansion is more comprehensive. The pressure cuts down the expansion soon though, due to a reduction in the air intake, and due to losses in the exhaust and combustor.

Gas turbines are normally made and lined with components of ceramic, nickel, steel and other strong materials that can withstand enormous heat and pressure at the same time, provided that some parts of the machine are kept cool as these materials do not withstand more than a specific level of pressure or temperature.

The Basic Mechanism

Basically, the gas turbine derives energy through a combustion gas flow.

The major components in a gas turbine are a compressor and a turbine, with a combustion chamber located in the midst. In the combustor, some kind of fuel is mixed well with air and then ignited. The temperature in the combustor is thus significantly increased due to the combustion of fuel that takes place within its structure.

The gas from the combustion process is then passed in a jet through the turbine, which will normally be located in the lower section of the engine. The gas will be passed through a nozzle with very high speed and in a directed manner. This will effectively spin the turbine when passed in a jet over it, thus powering up the compressor. This way a significant mechanical output is obtained.

The power released in a gas turbine is quite high, and for this reason, such gas turbines are used to power ships, aircraft, trains, tanks and even generators. The fields where such gas turbines can be used are vast, and these remain one of the most sought after engines in the industry today because of their efficiency and small dimensions!