Figure 2-16.--DD and DDG exhaust eductor.
It is positioned so the gas flow from
the exhaust nozzles will draw outside air into
the exhaust stream. It also draws IR suppression
Figure 2-15.--DD exhaust duct systems.
spray into the exhaust as it enters the mixing
tube.
DD AND CG EXHAUST
DUCT SYSTEMS
These ship classes have replaced the outmoted IR
suppression system with the boundary layer infared
suppression system (BLISS), figure 2-17. Figure 2-15
shows a cross-sectional view of the DD exhaust duct
system.
Silencers
A single vane type of silencer is located in the
center of the exhaust duct. It has sound-deadening
material encased in perforated stainless steel sheet.
This material, along with the duct wall insulation,
reduces the sound level enough to meet acceptable
airborne noise requirements.
Eductors
Figure 2-16 is a cross-sectional view of an
eductor. The exhaust eductors are located at the
top of each propulsion engine exhaust duct. It is
positioned so the gas flow from the exhaust
nozzle will draw outside air into the exhaust stream to
reduce exhaust gas temperature.
2-15
