文档介绍：SIA
Congrès International
« Le DIESEL : Aujourd'hui et demain »
Diesel multi-injection
combustion noise evaluation
Thierry Drecq
Nicolas Crotté
-
2004, May 13th
1
Table of Contents
Context
From vehicle noise bustion noise
dP/da as noise criteria for ECU calibration
Multi-injection detection
Osiris – Combustion analysis system
Application examples
Conclusion
2
Context
The main task in diesel engine tuning is to meet the
emission regulations, keeping customer’s
satisfaction (fuel economy, torque, noise,…), and
reducing tuning cost.
Three major concerns leads to ECU calibration
goals :
Ø Respect emissions regulations
Ø Adapt to petitive market
Ø Satisfy customer’fort = noise
3
Vehicle noise
Every new vehicle introduced on the market needs an
homologation in terms of noise
Normalized test è noise level in dB
This test measures the resultant of different noises :
Ø Aerodynamic noise
Ø Exhaust noise
Ø Radiated noise
The overall is the noise felt from outside the vehicle
It is different from the noise felt by the driver, which is
mainly due to the radiated noise
4
Noise sources illustration
Radiated noise
Vibration energy
Radiated acoustic energy
Exhaust
noise
Aerodynamic noise
5
Vehicle noise
When designing a vehicle, special care is given to filter the
radiated noise in order to have the best fort
for the end user
Practically :
Ø vibration is filtered with all linking elements of the
engine to the vehicle
Ø Acoustic energy will be filtered with all the mass
present between the driver and the engine (structural
attenuation : bustion noise to decibels)
Limiting the noise due to bustion will permit to
reduce the mass required for a good structural attenuation
6
Noise & dP/da
dP/da = image of the source noise
more “universal” than the noise level in dB
10 years ago = Single injection strategy :
Maximum pressure gradient (dP/da) during one engine
cycle = image