TABLE OF CONTENTS "Never mistake motion for action."
Ernest Hemingway
At some point, a gas turbine operations or repair and overhaul engineer has to consider the design of the gas turbine package in his or her care. This may be for
Specification of a new package or system.
An engineering a retrofit package.
Arguing a warranty case.
Troubleshooting or failure analysis.
Regardless of the reason for a look at the gas turbine system design, it is useful to know the terminology and basic theory behind the OEM's design. What follows is a summary of an OEM's basic theory and terminology in the design areas of
Operational envelope.
Properties and charts for dry air, combustion products, and other working fluids.
"Design point" definitions and terminology.
After these sections, there are two case studies and a Mach number/altitude chart developed by an aircraft engine designer.
The very basic thermodynamic laws and cycle diagrams used by operational engineers with little or no design (retrofit or otherwise) or specification responsibility are in the chapter on gas turbine cycles.
The performance thrust or power, fuel consumption, temperatures, shaft speeds etc. of a gas turbine engine is crucially dependent upon its inlet and exit conditions. The most important items are pressure and temperature, which are determined by the combination of ambient values and any changes due to flight speed, or pressure loss imposed by the installation.
The full range of inlet conditions that a given gas turbine engine application could encounter is encompassed in the operational envelope.
