EFFECTIVITY
ALL CFM56 ENGINES
CFMI PROPRIETARY INFORMATION
CFM56-ALL
TRAINING MANUAL
BASIC ENGINE
PARTICULARS
BORESCOPE INSPECTION
Page 34
Sep 03
COMBUSTOR SECTION
(-5B, -7B) :
Double Annular Combustor (DAC).
The combustion case has 20 double-tip fuel nozzles
mounting pads and accommodates 3 fuel supply
manifolds.
The combustion chamber is a short, conical structure
with a double burner and is contained in the combustion
case.
The Double Annular Combustor has an outer dome,
known as pilot, and an inner dome, known as main.
The DAC consists of :
- outer and inner liners.
- cowl.
- centerbody.
- 20 pilot swirl cups.
- 20 main swirl cups.
The outer and inner liners are designed with panel
overhangs which have closely spaced holes providing
air film cooling. Both inner and outer liners are thermal
barrier coated.
The cowl forms the front end of the combustor and is
scalloped to allow passage for HPC delivery air and for
fuel nozzles installation.
The centerbody separates the pilot area from the main
area. There are 40 centerbodies that are a cast part,
which is cooled through film air cooling holes and internal
heat transfer is increased by fins.
Each swirl cup consists of a primary and a secondary
swirl nozzle. They force the air to rotate in opposite
directions for efficient mixing of air with fuel.
TOC
