Experimental Study of Pressure and Velocity Fluctuations Induced by Cavitation in a Small Venturi Channel

Zhang, Linrong; Zhang, Guangjian; Ge, Mingming; Coutier-Delgosha, Olivier

doi:10.3390/en13246478

Cited by 7 publications

(2 citation statements)

References 29 publications

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“…Further, the temperature can be measured by LIF, but with different techniques based, for instance, on the spectral analysis of the emitted light (see, e.g., the recent study of Orea et al [189], about the most suitable tracer for high-temperature molten salt applications, of Zhu et al [190], about the applications of LIF to the combustion diagnostics and practical engine measurements, or of McManamen et al [191], about the shock-wave-turbulence interactions in high-speed flight and propulsion). LIF can be coupled with PIV to obtain simultaneous measures of concentration and velocity (see, e.g., Savitskii et al [192], Zhang et al [193], Charogiannis et al [194]).…”

Section: Digital Image Analysis (Dia) Techniquesmentioning

confidence: 99%

A Review of Laboratory and Numerical Techniques to Simulate Turbulent Flows

Ferrari

Rossi²,

Bernardino

2022

Energies

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Turbulence is still an unsolved issue with enormous implications in several fields, from the turbulent wakes on moving objects to the accumulation of heat in the built environment or the optimization of the performances of heat exchangers or mixers. This review deals with the techniques and trends in turbulent flow simulations, which can be achieved through both laboratory and numerical modeling. As a matter of fact, even if the term “experiment” is commonly employed for laboratory techniques and the term “simulation” for numerical techniques, both the laboratory and numerical techniques try to simulate the real-world turbulent flows performing experiments under controlled conditions. The main target of this paper is to provide an overview of laboratory and numerical techniques to investigate turbulent flows, useful for the research and technical community also involved in the energy field (often non-specialist of turbulent flow investigations), highlighting the advantages and disadvantages of the main techniques, as well as their main fields of application, and also to highlight the trends of the above mentioned methodologies via bibliometric analysis. In this way, the reader can select the proper technique for the specific case of interest and use the quoted bibliography as a more detailed guide. As a consequence of this target, a limitation of this review is that the deepening of the single techniques is not provided. Moreover, even though the experimental and numerical techniques presented in this review are virtually applicable to any type of turbulent flow, given their variety in the very broad field of energy research, the examples presented and discussed in this work will be limited to single-phase subsonic flows of Newtonian fluids. The main result from the bibliometric analysis shows that, as of 2021, a 3:1 ratio of numerical simulations over laboratory experiments emerges from the analysis, which clearly shows a projected dominant trend of the former technique in the field of turbulence. Nonetheless, the main result from the discussion of advantages and disadvantages of both the techniques confirms that each of them has peculiar strengths and weaknesses and that both approaches are still indispensable, with different but complementary purposes.

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Section: Digital Image Analysis (Dia) Techniquesmentioning

confidence: 99%

A Review of Laboratory and Numerical Techniques to Simulate Turbulent Flows

Ferrari

Rossi²,

Bernardino

2022

Energies

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“…All geometries are placed vertically in the hydraulic circuit. The authors also use a similar geometry for cavitation research [8,10,11].…”

Section: Circuit Description and Measurementmentioning

confidence: 99%

Identification of Cavitation by Noise

et al. 2022

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The identification of cavitation is very important in technical practice for operational and especially economic reasons. The article deals with the use of another way to measure noise during cavitation. The current approach of measuring noise with an intensity probe is used in practice for identification, but it does not immediately address the position of the cavitation source for a given frequency range. Measurement by an acoustic camera is not entirely common in practice, but it allows to determine the location of the noise source for a given frequency range. To test the acoustic camera, the authors focused on the cavitating flow in a hydraulic circuit with three previously tested nozzles. Noise was measured for these nozzles using an acoustic intensity probe with two microphones. The results were evaluated by statistical methods and compared with measurements using an acoustic camera. The aim of the article is to point out the advantages of using this approach for accurate area identification of the problem. Research background: The work is focused on the issue of cavitation and its identification in the hydraulic circuit. For cavitation research, a variant of cavitation identification by noise was chosen. However, this measurement brings problems that are only revealed through more sophisticated and accurate measurements. Purpose of the article: The purpose of the article is to point out other possibilities of measuring cavitation noise using modern technologies and subsequently verify the results. Methods: Metody: A common way of measuring noise is to measure it with a suitably located acoustic intensity probe. A more modern approach is area noise measurement. Measurement methodology and benefits are described. Findings & Value added: The commonly used way of measuring noise using an acoustic intensity probe has proved to be insufficient, as it is not possible to distinguish the location of sources in the case of complex measurements. When using an acoustic camera, there are more sources of noise in a given circuit and they are detected according to the required frequencies in different places than expected. The article points out the specific identification of noise sources using the frequency spectrum of noise for selected elements.

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