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Acoustic Field
The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Wolfgang Polifke – One of the best experts on this subject based on the ideXlab platform.
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modulation of spray droplet number density and size distribution by an Acoustic Field
The Journal of Computational Multiphase Flows, 2017Co-Authors: Javier Achury, Wolfgang PolifkeAbstract:Multiple interactions may occur when a poly-disperse spray is exposed to an Acoustic Field. In the context of spray combcombustion instabilities, Acoustic agglomeration, the formation of a droplet numb…
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modulation of spray droplet number density and size distribution by an Acoustic Field
International Conference on Multiphase Flow 2016, 2016Co-Authors: Javier Achury, Wolfgang PolifkeAbstract:Multiple interactions may occur when a poly-disperse spray is immersed in an Acoustic Field. In the context of spray combcombustion instabilities, Acoustic agglomeration, the formation of a droplet number density wave and the modulation of the droplet size distribution are important effects. A droplet number density wave, i.e. preferential concentration of droplets in space, may result from sizedependent, one-way momentum coupling between the Acoustic Field and the spray. The modulation of the droplet size distribution, which has been evidenced in the experimental work of Gurubaran and Sujith (AIAA 2008-1046), is then a consequence of the droplet number density wave formation. In the present work the mechanisms that produce these effects, including Acoustic agglomeration, are simulated and analyzed in depth by means of CFD. The spray is modeled with both Lagrangian (particles mass-point approach) and Eulerian (continuous phase approach) descriptions. The particular Eulerian method used is the presumed density function Method of Moments, which allows to account for the effects of poly-dispersity. Both the Lagrangian and Eulerian models are validated against experimental data for spray dynamics and spray response to an Acoustic Field.
Javier Achury – One of the best experts on this subject based on the ideXlab platform.
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modulation of spray droplet number density and size distribution by an Acoustic Field
The Journal of Computational Multiphase Flows, 2017Co-Authors: Javier Achury, Wolfgang PolifkeAbstract:Multiple interactions may occur when a poly-disperse spray is exposed to an Acoustic Field. In the context of spray combustion instabilities, Acoustic agglomeration, the formation of a droplet numb…
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modulation of spray droplet number density and size distribution by an Acoustic Field
International Conference on Multiphase Flow 2016, 2016Co-Authors: Javier Achury, Wolfgang PolifkeAbstract:Multiple interactions may occur when a poly-disperse spray is immersed in an Acoustic Field. In the context of spray combustion instabilities, Acoustic agglomeration, the formation of a droplet number density wave and the modulation of the droplet size distribution are important effects. A droplet number density wave, i.e. preferential concentration of droplets in space, may result from sizedependent, one-way momentum coupling between the Acoustic Field and the spray. The modulation of the droplet size distribution, which has been evidenced in the experimental work of Gurubaran and Sujith (AIAA 2008-1046), is then a consequence of the droplet number density wave formation. In the present work the mechanisms that produce these effects, including Acoustic agglomeration, are simulated and analyzed in depth by means of CFD. The spray is modeled with both Lagrangian (particles mass-point approach) and Eulerian (continuous phase approach) descriptions. The particular Eulerian method used is the presumed density function Method of Moments, which allows to account for the effects of poly-dispersity. Both the Lagrangian and Eulerian models are validated against experimental data for spray dynamics and spray response to an Acoustic Field.
Gang Zhou – One of the best experts on this subject based on the ideXlab platform.
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Modulating of traveling-standing wave Acoustic Field in the thermoAcoustic resonator
The Journal of the Acoustical Society of America, 2012Co-Authors: Xin Huang, Gang ZhouAbstract:In this paper, a double-loudspeakers model to modulate the Acoustic Field in the resonator is presented. The Acoustic Field is modulated by changing the driving conditions, including the amplitude and the phase difference of the driving voltages. A numerical simulation for the Acoustic Field in the resonator without regenerator is carried out. The calculation results indicate that any traveling-standing wave Acoustic Field can be obtained by changing the driving conditions. The Acoustic Field in the resonator with regenerator is also simulated. It is found that the Acoustic Field in the regenerator can be modulated in a wide range and several targeted Acoustic Field conditions can be obtained feasibly, which are useful for achieving the optimal thermoAcoustic conversion. An experimental device has been constructed and tested. The Acoustic Field are measured and reconstructed under different driving conditions. The experiment results are in good agreement with the simulations. The device provides a platfor…
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The influence of thermoAcoustic regenerator on a traveling-wave Acoustic Field
The Journal of the Acoustical Society of America, 2012Co-Authors: Gang Zhou, Xin HuangAbstract:ThermoAcoustic device can realize conversion between the heat energy and Acoustic energy. Regenerator is the core of a thermoAcoustic engine or refrigerator, which consists of smooth or tortuous porous media, such as parallel plates or stainless stacked-screen. Due to regenerators, the practical Acoustic Field is neither a pure standing wave nor a pure travelling wave. In fact, the position, structural parameters of the regenerator and temperature gradient between heat exchangers will strongly influence the oscillating pressure and velocity distribution in the Acoustic Field, which will bring about different performance for a practical thermoAcoustic engine or refrigerator. In this paper, based on linear thermoAcoustic theory, a mathematical model of a 1/2 wave-length duct with a regenerator driven by speakers will be built and the influence of the regenerator on the Acoustic Field distribution will be simulated and analyzed. This research is helpful for comprehensively understanding coupling mechanism be…
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Synthetical optimization of hydraulic radius and Acoustic Field for thermoAcoustic cooler
Energy Conversion and Management, 2009Co-Authors: Huifang Kang, Gang ZhouAbstract:Abstract It is well known that the Acoustic Field and the hydraulic radius of the regenerator play key roles in thermoAcoustic processes. The optimization of hydraulic radius strongly depends on the Acoustic Field in the regenerator. This paper investigates the synthetical optimization of hydraulic radius and Acoustic Field which is characterized by the ratio of the traveling wave component to the standing wave component. In this paper, we discussed the heat flux, cooling power, temperature gradient and coefficient of performance of thermoAcoustic cooler with different combinations of hydraulic radiuses and Acoustic Fields. The calculation results show that, in the cooler’s regenerator, due to the Acoustic wave, the heat is transferred towards the pressure antinodes in the pure standing wave, while the heat is transferred in the opposite direction of the wave propagation in the pure traveling wave. The better working condition for the regenerator appears in the traveling wave phase region of the like-standing wave, where the directions of the heat transfer by traveling wave component and standing wave component are the same. Otherwise, the small hydraulic radius is not a good choice for Acoustic Field with excessively high ratio of traveling wave, and the small hydraulic radius is only needed by the traveling wave phase region of like-standing wave.
Lin Guan-cheng – One of the best experts on this subject based on the ideXlab platform.
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Analysis and Simulationof Vector Acoustic Field based on Parabolic Equation Method
Computer Simulation, 2012Co-Authors: Lin Guan-chengAbstract:Sound propagation in the ocean is a classical underwater Acoustic research problem.In traditional studies,researchers are primarily concerned about sound pressure Fields and ignore the joint processing between particle velocities and sound pressure,and the studies for the vector Acoustic Field of low frequency are also lacking.Aim at the above-mentioned issues,calculation model of vector Acoustic Field was given by Euler equations,and parabolic equation method was used to calculate sound pressure.The numerical solutions of vector Field parameters,such as particle velocity of Acoustic Field,were given using difference method.It analyzed the vector Acoustic Field in shallow sea overlying an elastic bottom.Simulation results indicate that using parabolic equation method can quickly and accurately calculate the vector Acoustic Field of marine environment and implement the joint processing between particle velocity and sound pressure.It can be applied to the rapid prediction of vector Acoustic Field.
Dejie Yu – One of the best experts on this subject based on the ideXlab platform.
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Interval analysis of Acoustic Field with uncertain-but-bounded parameters
Computers & Structures, 2012Co-Authors: Baizhan Xia, Dejie YuAbstract:This paper presents an interval perturbation finite element method (IPFEM) and a modified interval perturbation finite element method (MIPFEM) for the uncertain Acoustic Field prediction with uncertain-but-bounded parameters. The interval matrix and vector in both methods are expanded by the first-order Taylor series. The interval matrix inverse in IPFEM is approximated by the first-order Neumann series; however, the interval matrix inverse in MIPFEM is approximated by a modified Neumann expansion in which the higher order terms of Neumann series are considered. Numerical results demonstrate the accuracy of MIPFEM to evaluate the intervals of sound pressure response in Acoustic Field.