15.5 COMBUSTION Flashcards
what does the combustion chamber do
raises the temp of the air
for safe operation of the engine what must the combustion chamber follow
safe ignition, stable combustion, combustion must be complete
the combustion chamber must be
small and light, dependable cooling system for materials in contact, high operating lifetime
what are the 2 main component of the combustion chamber
chamber casing, flame tube
the casing can be split into what
inner and outer
what does the flame tube do
controls and guides the flame
there is stable combustion as long as
fuel and air are supplied to the chamber
what are the 2 factors required for safe combustion
ratio of air to fuel, air velocity slow enough to make sure combustion takes place in the chamber
what is the correct air to fuel mix ratio
15 parts air, 1 part fuel
what is the airflow from the compressor split into
primary, secondary
which airflow is used for combustion and what percentage
primary, 20-30%
what are the 3 types of combustion chamber used of gas turbine engines
can-type, can-annular, annular
describe can-type combustion chambers
old gas turbine with centrifugal compressors, each chamber has its own air supply, fuel nozzle, flame tube, casing, used for small engines
what are advantages of the can-annular combustion chamber
smaller and lighter
what are the disadvantages of the can-annular combustion chamber
aerodynamic loss and require strong ignition
where are annular combustion chambers commonly used
modern gas turbine
how many flame tubes does an annular combustion chamber have
1
what are the 3 major parts of the annular combustion chamber
dome, inner liner, outer liner
what are the disadvantages of annular combustion chambers
expensive and time consuming to remove
what sections does an annular combustion chamber have
combustion case, flame tube, external components
the combustion chase parts have
an outer wall, inner wall, diffuser
the main components of the flame tube are
outer and inner liner, outer and inner cowl, dome
what is the secondary air used for in the combustion chamber
cooling
what cooling method is used around the combustion chamber
film cooling
what is a more sophisticated version of film cooling
transpiration cooling
how is an incorrect amount of emisions released
wrong air:fuel ratio
