scholarly journals Acoustic Characteristics Analysis of Liquid-filled Muffler Based on the Structural Acoustic Coupling

2021 ◽  
Vol 5 (4) ◽  
pp. 338-348
Author(s):  
Shuailong Zhou ◽  
Zhi Fang
Keyword(s):  
Acoustic Characteristics ◽  
Acoustic Coupling ◽  
Characteristics Analysis

Acoustic Sensitivities of Lean-Premixed Fuel Injectors in a Single Nozzle Rig

1999 ◽  
Vol 121 (3) ◽  
pp. 429-436 ◽  
Author(s):  
D. W. Kendrick ◽  
T. J. Anderson ◽  
W. A. Sowa ◽  
T. S. Snyder
Keyword(s):  
Mach Number ◽  
Bluff Body ◽  
Dynamical Behavior ◽  
Flame Stabilization ◽  
Acoustic Characteristics ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Acoustic Coupling ◽  
Lean Premixed ◽  
Exit Mach Number

An experimental and numerical investigation into the attenuation of combustion induced pressure oscillations in a single nozzle rig was undertaken at the United Technologies Research Center. Results from these investigations indicated a high combustor exit Mach number, similar to that used in a gas turbine engine, was required to correctly simulate the combustor dynamics and evaluate acoustic characteristics of lean premixed fuel injectors. Comparisons made between aerodynamically stabilized and bluff-body stabilized nozzles and the use of premixed and diffusion pilots showed that small levels of diffusion piloting behind a bluff-body yielded the best acoustic/emission performance. Their success is due to increased flame stabilization (superior anchoring ability), which reduced flame motion and thermal/acoustic coupling. For cases where diffusion piloting was not present, both designs exhibited similar dynamical behavior. Increases in the combustor exit Mach number and reductions in the inlet air temperature were shown to degrade acoustic performance of both nozzle designs. The bluff-body configuration with small levels of diffusion piloting, however, was found to be less sensitive to these changes when compared to its aerodynamic counterpart.

scholarly journals Recovering the Free-Field Acoustic Characteristics of a Vibrating Structure from Bounded Noisy Underwater Environments

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5521
Author(s):  
Wei Lin ◽  
Sheng Li
Keyword(s):  
Rigid Body ◽  
Free Field ◽  
Sound Field ◽  
Coupling Method ◽  
Noisy Environments ◽  
Acoustic Characteristics ◽  
Acoustic Coupling ◽  
Vibrational Behavior ◽  
Measurement Surface ◽  
The Difference

The vibrational behavior of an underwater structure in the free field is different from that in bounded noisy environments because the fluid–structure interaction is strong in the water and the vibration of the structure caused by disturbing fields (the reflections by boundaries and the fields radiated by sources of disturbances) cannot be ignored. The conventional free field recovery (FFR) technique can only be used to eliminate disturbing fields without considering the difference in the vibrational behavior of the structure in the free field and the complex environment. To recover the free-field acoustic characteristics of a structure from bounded noisy underwater environments, a method combining the boundary element method (BEM) with the vibro-acoustic coupling method is presented. First, the pressures on the measurement surface are obtained. Second, the outgoing sound field and the rigid body scattered sound field are calculated by BEM. Then, the vibro-acoustic coupling method is employed to calculate the elastically radiated scattered sound field. Finally, the sound field radiated by the structure in the free field is recovered by subtracting the rigid body scattered sound field and the elastically radiated scattered sound field from the outgoing sound field. The effectiveness of the proposed method is validated by simulation results.

scholarly journals Acoustic Sensitivities of Lean-Premixed Fuel Injectors in a Single Nozzle Rig

1998 ◽  
Author(s):  
Donald W. Kendrick ◽  
Torger J. Anderson ◽  
William A. Sowa ◽  
Timothy S. Snyder
Keyword(s):  
Mach Number ◽  
Bluff Body ◽  
Dynamical Behavior ◽  
Flame Stabilization ◽  
Acoustic Characteristics ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Acoustic Coupling ◽  
Lean Premixed ◽  
Exit Mach Number

An experimental and numerical investigation into the attenuation of combustion induced pressure oscillations in a single nozzle rig was undertaken at the United Technologies Research Center. Results from these investigations indicated a high combustor exit Mach number, similar to that used in a gas turbine engine, was required to correctly simulate the combustor dynamics and evaluate acoustic characteristics of lean premixed fuel injectors. Comparisons made between aerodynamically stabilized and bluff-body stabilized nozzles and the use of premixed and diffusion pilots showed that small levels of diffusion piloting behind a bluff-body yielded the best acoustic/emission performance. Their success is due to increased flame stabilization (superior anchoring ability) which reduced flame motion and thermal/acoustic coupling. For cases where diffusion piloting was not present, both designs exhibited similar dynamical behavior. Increases in the combustor exit Mach number and reductions in the inlet air temperature were shown to degrade acoustic performance of both nozzle designs. The bluff-body configuration with small levels of diffusion piloting, however, was found to be less sensitive to these changes when compared to its aerodynamic counterpart.

scholarly journals Acoustic Characteristics Analysis of Industrial Premises with Process Equipment

2016 ◽  
Vol 04 (02) ◽  
pp. 206-210 ◽  
Author(s):  
I. Tsukernikov ◽  
A. Antonov ◽  
V. Ledenev ◽  
I. Shubin ◽  
T. Nevenchannaya
Keyword(s):  
Process Equipment ◽  
Acoustic Characteristics ◽  
Characteristics Analysis
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