In-duct acoustic source model considering flow characteristics at orifice and valve inside fluid machinery

2007 ◽  
Vol 122 (5) ◽  
pp. 2964
Author(s):  
Tae-Kyoon Kim ◽  
Jeong-Guon Ih
Keyword(s):  
Flow Characteristics ◽  
Source Model ◽  
Acoustic Source ◽  
Fluid Machinery

scholarly journals An acoustic source model for asymmetric intraglottal flow with application to reduced-order models of the vocal folds

PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0219914
Author(s):  
Byron D. Erath ◽  
Sean D. Peterson ◽  
Kelley S. Weiland ◽  
Michael W. Plesniak ◽  
Matías Zañartu
Keyword(s):  
Vocal Folds ◽  
Source Model ◽  
Reduced Order Models ◽  
Acoustic Source ◽  
Reduced Order

An Investigation of Slug Flow in Hilly Terrain Pipelines

2001 ◽  
Author(s):  
Suat Bagci ◽  
Adel Al-Shareef
Keyword(s):  
Liquid Film ◽  
Slug Flow ◽  
Flow Characteristics ◽  
Source Model ◽  
Pipe Diameter ◽  
Liquid Holdup ◽  
Hilly Terrain ◽  
Two Phase ◽  
Flow Interactions ◽  
Inclined Pipes

Abstract Two-phase flow in hilly terrain pipelines can cause significant practical operating problems. When slugs flow in a hilly terrain pipeline that contains sections of different inclinations they undergo a change of length and slug flow characteristics as the slug move from section to section. In addition, slugs can be generated at low elbows, dissipate at top elbows and shrink or grow in length as they travel along the pipe. A mathematical model and a computer program was developed to simulate these phenomena. The model was based on the sink/source concept at the pipeline connections. A connection between two pipeline sections of different slopes was conveniently called elbow. An elbow accumulates liquid as a sink, and releases liquid as a source. The sink/source has a characteristic capacity of its own. This capacity is positive if the liquid can indeed be accumulated at the elbow or negative if the liquid is actually drained away from the elbow. This type of treatment effectively isolates the flow upstream from an elbow from that downstream, while still allowing flow interactions between two detailed pipeline sections. The hydrodynamic flow model was also used to calculate the film liquid holdup in horizontal and inclined pipelines. The model can successfully predict the liquid film holdup if the liquid film height is assumed to be uniform through the gas pocket. Many other models were used to calculate all the needed parameters to perform the sink/source model. The overall effect of a hill or terrain on slug flow depends on the operating flow rates and pipeline configurations. For special case of near constant slug frequency corresponding to moderately high superficial liquid and gas velocities, this effect was found to be small. The changes in the film characteristics between two adjacent pipeline sections were found to be mostly responsible for the pseudo-slug generation, slug growth and dissipation in the downstream pipeline sections. The film liquid holdup decreased with increasing pipe diameter. The unit slug length increased at the upstream inclined pipes and decreased at the downstream inclined pipes with increasing pipe diameter. The possibility of pseudo-slug generation was increased at large pipe diameters even at high sink capacities. At low sink capacities, no pseudo-slugs were generated at high superficial velocities. The slug flow characteristics was more effected by low superficial gas and liquid velocities, large pipe diameters and shallow pipeline inclinations.

A hydro‐acoustic source model in calculating noise field generated by breaking waves

2005 ◽  
Vol 118 (3) ◽  
pp. 2003-2003
Author(s):  
Xuemei Chen ◽  
Steven L. Means ◽  
William G. Szymczak ◽  
Joel C. W. Rogers
Keyword(s):  
Breaking Waves ◽  
Source Model ◽  
Acoustic Source ◽  
Noise Field

Diesel Engine Combustion Monitoring Based on Acoustic Measurement of Exhaust Systems

2006 ◽  
Author(s):  
R. Gennish ◽  
J. Jiang ◽  
A. Albarbar ◽  
G. Harris ◽  
F. Gu ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Exhaust System ◽  
Source Model ◽  
Acoustic Measurement ◽  
Engine Fuel ◽  
Acoustic Source ◽  
Engine Combustion ◽  
Combustion Monitoring ◽  
Exhaust Systems

This paper presents a novel monitoring approach to diesel engine combustion based on acoustic measurement of exhaust systems. It investigates the acoustic characteristics from the measurements of individual sensors and their combination based on a linear one port acoustic source model. It has been found that the strength, in terms of pressure, of the acoustic source gives a more accurate representation of engine acoustics because it is obtained by minimizing the reflection effects in the exhaust system. Therefore, the pressure waveform produces more accurate monitoring results for abnormal combustions such as those caused by faults in engine fuel injection systems.

Physical Insight of the Source Data of a Two-Port Acoustic Source Model

2010 ◽  
Vol 44-47 ◽  
pp. 3413-3417
Author(s):  
Bin Zhang ◽  
Xue Jun Liu ◽  
Rui Xiang Song ◽  
Bin Liu ◽  
Tao Feng
Keyword(s):  
Boundary Condition ◽  
External Source ◽  
Source Model ◽  
State Equation ◽  
Acoustic Source ◽  
Theoretical Derivation ◽  
Acoustic Boundary Condition ◽  
Source Data ◽  
Physical Insight ◽  
Full Absorption

The physical insight of the source data of two-port acoustic source model for a duct is studied in theoretical, experimental and numerical aspects respectively. Under the ideal acoustic boundary condition of full absorption at the duct ends, the state equation of two-port acoustic source model is discussed, and the physical insight of the source data is obtained through theoretical derivation. The experimental model of two-port acoustic source is established, and the source data have been measured by the method “with an external source”. The physical meaning of source data has been demonstrated through the experimental method. The numerical simulating model for the experiment system is built, and the source data obtained numerically are compared with those measured experimentally for research. From the comparison, it is concluded that the source data of two-port acoustic source model are the traveling wave propagating outside along the duct under the acoustic boundary condition of full absorption at duct ends.

Empirical Acoustic Source Model for Chemical Explosions in Air

2021 ◽  
Author(s):  
Keehoon Kim ◽  
Arthur R. Rodgers ◽  
Milton A. Garces ◽  
Stephen C. Myers
Keyword(s):  
Acoustic Waves ◽  
Scaling Law ◽  
Source Model ◽  
Significant Loss ◽  
Acoustic Energy ◽  
Statistical Characteristics ◽  
Yield Estimation ◽  
Acoustic Source ◽  
Explosion Monitoring ◽  
Chemical Explosions

ABSTRACT Chemical explosions generate pressure disturbances in air that radiate as nonlinear shock waves near the source and transition into acoustic waves with distance. Because low-frequency acoustic waves generally travel large distances without significant loss of energy, they are often used for explosion monitoring and yield estimation. However, quantitative relationships between acoustic energy and explosion yields are required for accurate yield estimation. Here, we develop an empirical acoustic source model for chemical explosions from experimental data. The empirical model returns the acoustic pressure waveform for the detonation of 1 kg of trinitrotoluene, which is conventionally used to represent the explosive release of 4.184 MJ of explosion energy. The full-waveform model can be used to predict acoustic signals for an arbitrary yield of a high-explosive detonation based on the standard scaling law and to estimate acoustic energies in a specific frequency range. We evaluate the accuracy of the acoustic source model independently by estimating the yield of other explosive events that are not included in the model development. Statistical characteristics of the model and their implications for the uncertainty quantification of estimated yields are discussed.

Data-educed broadband equivalent acoustic source model for supersonic jet noise

2019 ◽  
Vol 146 (5) ◽  
pp. 3409-3424
Author(s):  
Tracianne B. Neilsen ◽  
Aaron B. Vaughn ◽  
Kent L. Gee ◽  
Masahito Akamine ◽  
Koji Okamoto ◽  
...  
Keyword(s):  
Supersonic Jet ◽  
Jet Noise ◽  
Source Model ◽  
Acoustic Source ◽  
Supersonic Jet Noise
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