Numerical investigation of combustion noise: The Entropy Wave Generator

Numerical Investigation of Effect Pilot Injection on Combustion Noise and Exhaust Emission of Diesel Engine The traditional mechanical fuel supply system has already been no way to satisfy the requirement of more stringent fuel consumption and emission legislation. For the past few years, it has been a hot topic to improve performance of diesel engine combustion and emission through optimizing the fuel injection strategy. All kinds of spray, combustion and emission models were studied and then the numerical models for the single-injection combustion of 1015 diesel engine were setup and validated through comparing with results from experimental data. With the above verified models, different injection strategies were further investigated to get the effect mechanism of pilot injection (PI) timing and quantity on combustion noise and exhaust emission.

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Numerical investigation of combustion noise from aeronautical combustor to far-field

22nd AIAA/CEAS Aeroacoustics Conference ◽

10.2514/6.2016-2747 ◽

2016 ◽

Cited By ~ 2

Author(s):

Mélissa Férand ◽

Thomas Livebardon ◽

Stephane Moreau ◽

Thierry Poinsot ◽

Claude Sensiau

Keyword(s):

Numerical Investigation ◽

Combustion Noise ◽

Far Field

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Numerical Investigation of Combustion Noise and Sound Source Mechanisms in a Non-Premixed Flame Using LES and APE-RF

13th AIAA/CEAS Aeroacoustics Conference (28th AIAA Aeroacoustics Conference) ◽

10.2514/6.2007-3406 ◽

2007 ◽

Cited By ~ 5

Author(s):

Thanh Bui ◽

Matthias Ihme ◽

Matthias Meinke ◽

Wolfgang Schroeder ◽

Heinz Pitsch

Keyword(s):

Numerical Investigation ◽

Sound Source ◽

Combustion Noise ◽

Premixed Flame ◽

Source Mechanisms

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Large-Eddy-simulation prediction of indirect combustion noise in the entropy wave generator experiment

International Journal of Spray and Combustion Dynamics ◽

10.1177/1756827717740775 ◽

2017 ◽

Vol 10 (2) ◽

pp. 154-168 ◽

Cited By ~ 4

Author(s):

Stéphane Moreau ◽

C Becerril ◽

LYM Gicquel

Keyword(s):

Pressure Fluctuations ◽

Large Eddy Simulations ◽

Combustion Noise ◽

Analytical Models ◽

Computational Domain ◽

Mean Flow ◽

Long Distance ◽

Acoustic Reflection ◽

Large Eddy ◽

Wave Generator

Compact and non-compact analytical solutions of the subsonic operating point of the entropy wave generator experiment are compared with detailed numerical results obtained by large Eddy simulations. Two energy deposition methods are presented to account for the experimental ignition sequence and geometry: a single-block deposition as previously used and a delayed deposition that reproduces the experimental protocle closely. The unknown inlet acoustic reflection coefficient is assumed to be fully reflective to be more physically consistent with the actual experimental setup. The time delay between the activation of the heating modules must be considered to retrieve the temperature signal measured at the vibrometer and pressure signals at the microphones. Moreover, pressure signals extracted from the large Eddy simulations in the outlet duct using the delayed ignition model clearly reproduce the experimental signals better than the analytical models. An additional simulation with actual temperature fluctuations directly injected at the inlet of the computational domain clearly shows that the pressure fluctuations produced by the acceleration of the hot slug yields indirect noise almost entirely. Finally, the entropy spot is shown to be distorted when convecting through the turbulent flow in the entropy wave generator nozzle. Its amplitude decreases and its shape is dispersed, but hardly any dissipation occurs. The distortion appears to be negligible through the nozzle and become important only when convected over a long distance in the downstream duct. As the dominant frequencies of the entropy wave generator entropy forcing are very low, the effects of dispersion by the mean flow are however weak.

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