Describe the Brayton cycle and its application in gas turbines.

The Brayton cycle is the ideal cycle for gas turbines, consisting of isentropic compression (compressor), constant-pressure heat addition (combustion chamber), isentropic expansion (turbine), and constant-pressure heat rejection (exhaust). Efficiency increases with pressure ratio and turbine inlet temperature but is limited by compressor efficiency and material temperature limits. Regeneration, intercooling, and reheat can improve efficiency. Applications include aircraft jet engines, power generation gas turbines, and combined cycle plants.