Thermoacoustic Properties of Can Annular Combustors

AbstractFlavonoids amongst the class of secondary metabolites possess numerous health benefits, are known for its use in pharmaceutical industry. Quercetin, a flavonoid has more prominent medical advantages however its utilization is constrained because of various instability and insolubility issues and therefore, taken into consideration for studying its physico-chemical properties. In view of that, the thermodynamic and thermoacoustic properties of quercetin were examined in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) at different hydroethanolic concentrations and temperatures. The conductivity studies were used to calculate change in enthalpy (∆Hom), change in entropy (∆Som) and change in Gibbs free Energy (∆Gom) of micellization. The interactions between quercetin and CTAB were found to be endothermic, entropically controlled and spontaneous. Further, ultrasonic sound velocity and density studies were carried out and utilized for the calculation of thermoacoustic parameters i.e. apparent molar volume and apparent molar compressibility. Thermoacoustic properties revealed that at higher surfactant concentration, hydrophobic interactions are dominant. The results suggested that the flavonoid-surfactant interactions in hydroethanolic solutions is more favourable as compared with aqueous solution. Overall, the data is favourable for the framework to be used for detailing advancement, drug development, drug industry, pharmaceutical industry, medical administration and formulation development studies.

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Estimation of the sharma constant and thermoacoustic properties of vegetable oils

Journal of the American Oil Chemists Society ◽

10.1007/bf02540471 ◽

1994 ◽

Vol 71 (8) ◽

pp. 901-905 ◽

Cited By ~ 6

Author(s):

M. S. R. Subrahmanyam ◽

H. Sumathi Vedanayagam ◽

P. Venkatacharyulu

Keyword(s):

Vegetable Oils ◽

Sharma Constant ◽

Thermoacoustic Properties

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Thermoacoustic properties of porous media

The Journal of the Acoustical Society of America ◽

10.1121/1.2029868 ◽

1991 ◽

Vol 89 (4B) ◽

pp. 2007-2007

Author(s):

Alon Koren ◽

Peter H. Ceperley

Keyword(s):

Porous Media ◽

Thermoacoustic Properties

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Thermoacoustic properties of fibrous materials

The Journal of the Acoustical Society of America ◽

10.1121/1.3425735 ◽

2010 ◽

Vol 127 (6) ◽

pp. 3470-3484 ◽

Cited By ~ 8

Author(s):

Carl Jensen ◽

Richard Raspet

Keyword(s):

Fibrous Materials ◽

Thermoacoustic Properties

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A Strategy to Tune Acoustic Terminations of Single-Can Test-Rigs to Mimic Thermoacoustic Behavior of a Full Engine

Volume 4B: Combustion, Fuels, and Emissions ◽

10.1115/gt2020-16078 ◽

2020 ◽

Author(s):

Matthias Haeringer ◽

Guillaume J. J. Fournier ◽

Max Meindl ◽

Wolfgang Polifke

Keyword(s):

Wave Theory ◽

Bloch Wave ◽

Reflection Coefficients ◽

Test Rig ◽

Helmholtz Resonators ◽

Flame Dynamics ◽

Annular Combustor ◽

Passive Acoustic ◽

Thermoacoustic Properties ◽

Dominant Frequencies

Abstract Thermoacoustic properties of can-annular combustors are commonly investigated by means of single-can test-rigs. To obtain representative results, it is crucial to mimic can-can coupling present in the full engine. However, current approaches either lack a solid theoretical foundation or are not practicable for high-pressure rigs. In the present study we employ Bloch-wave theory to derive reflection coefficients that correctly represent can-can coupling. We propose a strategy to impose such reflection coefficients at the acoustic terminations of a single-can test-rig by installing passive acoustic elements, namely straight ducts or Helmholtz resonators. In an iterative process, these elements are adapted to match the reflection coefficients for the dominant frequencies of the full engine. The strategy is demonstrated with a network model of a generic can-annular combustor and a 3D model of a realistic can-annular combustor configuration. For the latter we show that can-can coupling via the compressor exit plenum is negligible for frequencies sufficiently far away from plenum eigenfrequencies. Without utilizing previous knowledge of relevant frequencies or flame dynamics, the test-rig models are adapted within a few iterations and match the full engine with good accuracy. Using Helmholtz resonators for test-rig adaption turns out to be more viable than using straight ducts.

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A Strategy to Tune Acoustic Terminations of Single-Can Test-Rigs to Mimic Thermoacoustic Behavior of a Full Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4048642 ◽

2020 ◽

Author(s):

Matthias Haeringer ◽

Guillaume Jean Jacques Fournier ◽

Maximilian Meindl ◽

Wolfgang Polifke

Keyword(s):

Wave Theory ◽

Bloch Wave ◽

Reflection Coefficients ◽

Test Rig ◽

Helmholtz Resonators ◽

Flame Dynamics ◽

Annular Combustor ◽

Passive Acoustic ◽

Thermoacoustic Properties ◽

Dominant Frequencies

Abstract Thermoacoustic properties of can-annular combustors are commonly investigated by means of single-can test-rigs. To obtain representative results, it is crucial to mimic can-can coupling present in the full engine. However, current approaches either lack a solid theoretical foundation or are not practicable for high-pressure rigs. In the present study we employ Bloch-wave theory to derive reflection coefficients that correctly represent can-can coupling. We propose a strategy to impose such reflection coefficients at the acoustic terminations of a single-can test-rig by installing passive acoustic elements, namely straight ducts or Helmholtz resonators. In an iterative process, these elements are adapted to match the reflection coefficients for the dominant frequencies of the full engine. The strategy is demonstrated with a network model of a generic can-annular combustor and a 3D model of a realistic can-annular combustor configuration. For the latter we show that can-can coupling via the compressor exit plenum is negligible for frequencies sufficiently far away from plenum eigenfrequencies. Without utilizing previous knowledge of relevant frequencies or flame dynamics, the test-rig models are adapted within a few iterations and match the full engine with good accuracy. Using Helmholtz resonators for test-rig adaption turns out to be more viable than using straight ducts.

Download Full-text