GAS, STEAM & HYDRO TURBINES ENGINEERING HUB

Four processes occur in gas turbine engines, as illustrated above. These processes, first described by George Brayton and called the Brayton cycle, occur in all internal combustion engines. The Brayton steps are as follows: > Compression occurs between the intake and the outlet of the compressor (Line A-B). During this process, pressure and temperature of the air increases. > Combustion occurs in the combustion chamber where fuel and air are mixed to explosive proportions and ignited. The addition of heat causes a sharp increase in volume (Line B-C) > Expansion occurs as hot gas accelerates from the combustion chamber. The gases at constant pressure and increased volume enter the turbine and expand through it. The sharp decrease in pressure and temperature (Line C-D). > Exhaust occurs at the engine exhaust stack with a large drop in volume and at a constant pressure (Line D-A). The number of stages of compression and the arrangement...

The balloon drawings above illustrate the basic principles upon which gas turbine engines operate. Compressed inside a balloon, as in (A) above, exerts force upon the confines of the balloon. Air, which has weight and occupies space, by definition, has mass. The mass of the air is roportionalt to its density, and ensityi is roportionalt to temperature and pressure. The ir mass confined inside the balloon, accelerates from the balloon, creating a force as it is released (B). This force increases as mass and acceleration increase, as stated in Newton's second law; force equals mass times acceleration (F = MA). The force created by the acceleration of the air mass nside the balloon results n an equal and opposite force that causes the balloon to be propelled in the opposite direction, as stated in Newton's third law. For every action, there is an equal and opposite reaction.) Replacing the air inside the balloon, as in (C), sustains the force and, although impractical, allows a lo...