George Brayton designed the first continuous combustion engine, known as the Brayton engine, in the 1860s. The Brayton engine introduced the Brayton cycle of continuous combustion that became the basis for gas turbine development. A Brayton-type engine consists of an air compressor, mixing chamber, and expander. The Brayton cycle uses four thermodynamic processes - two constant pressure and two reversible adiabatic processes - and is now used in gas turbines where compression and expansion occur via rotating machinery.

1. By: John Eduard Carino

3. George Brayton
 Designed the first continuous ignition combustion
engine (Brayton’s ready motor)
 The machine he invented introduced the process of
continuous combustion (brayton cycle) which
became the basis of for development of gas turbine.
 His machine made headlines in scientific journals of
his time, but was superseded within a few years by
Nikolaus Otto’s engine a more efficient and quieter
design

4. Brayton Engine component
A Brayton-type engine consists of three
components:
 A gas compressor
 A mixing chamber
 An expander

6. Brayton Cycle
 A thermodynamic cycle (also variously
called the Joule or complete expansion
diesel cycle) consisting of two constant-
pressure (isobaric) processes
interspersed with two reversible
adiabatic (isentropic) processes.

7. Brayton Cycle
 Now, the Brayton cycle is used for gas
turbines only where both the compression
and expansion processes take place in
rotating machinery.

9. Brayton Cycle Components:
 First, Fresh air is drawn into the
compressor in which pressure and
temperature are raised
 The high-pressure air proceeds into the
combustion chamber, where the fuel
is burned at constant pressure.
 The resulting high-temperature gases
then enter the turbine, where they
expand to the atmospheric pressure
through a row of nozzle vanes

10. Brayton cycle components
 This expansion causes the turbine blade to
spin, which then turns a shaft inside a
magnetic coil. When the shaft is rotating
inside the magnetic coil, electrical current is
produced. The exhaust gases leaving the
turbine in the open cycle are not re-
circulated.

11. Processes and how they occur
 Isentropic process - Ambient air is drawn into the
compressor, where it is pressurized.
 Isobaric process - The compressed air then runs through
a combustion chamber, where fuel is burned, heating that
air—a constant-pressure process, since the chamber is
open to flow in and out.
 Isentropic process - The heated, pressurized air then
gives up its energy, expanding through a turbine (or series
of turbines). Some of the work extracted by the turbine is
used to drive the compressor.
 Isobaric process - Heat rejection (in the atmosphere).

13. Differences to other cycles
 The thermal efficiency for a given gas, air, is
solely a function of the ratio of compression.
This is also the case with the Otto cycle. For the
diesel cycle with incomplete expansion, the
thermal efficiency is lower.
 The Brayton cycle, with its high inherent thermal
efficiency, requires the maximum volume of gas
flow for a given power output.

14. Differences to other cycles
 The Otto and diesel cycles require much lower gas flow
rates, but have the disadvantage of higher peak pressures
and temperatures. These conflicting elements led to many
designs, all attempting to achieve practical compromises.
With the development of fluid acceleration devices for the
compression and expansion of gases, the Brayton cycle
found mechanisms which could economically handle the
large volumes of working fluid. This is perfected in the gas
turbine power plant.

15. Brayton Cycle

17. Open cycle and Closed
cycle

18.  The open gas-turbine cycle can be
modelled as a closed cycle by
utilizing the air-standard
assumptions. Here the compression
and expansion process remain the
same, but a constant-pressure heat-
rejection process to the ambient air
replaces the combustion process.

19. T-S and P-V diagram

20. Process 1-2

21. Process 2-3

22. Process 3-4

23. Process 4-1

25. Q added and Q rejected

26. Efficiency of a ideal Brayton
cycle

27. Efficiency of a ideal Brayton
cycle