Cavitating nozzle flows in micro- and minichannels under the effect of turbulence

Ghorbani, Morteza; Yıldız, Mehmet; Gözüaçık, Devrim; Koşar, Ali

doi:10.1007/s12206-016-0518-6

Cited by 26 publications

(14 citation statements)

References 25 publications

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“…8,9 Although jet impingement gives rise to cooling on an exposed surface and is considered an effective cooling method, 10−12 a rise in the surface temperature can be instead attained in the presence of intense bubbly cavitating flows downstream of the flow-restrictive elements. Our recent study illustrates that many cavitation bubbles were generated in channels with inner diameters of 256 and 504 μm and filled more space inside the channel compared to the conventional channels at higher upstream pressures, 13 which increased the possibility of the occurrence of collapse process at the outlet of the microchannels. These findings imply that the proposed method in this study is feasible.…”

Section: Introductionmentioning

confidence: 95%

Energy Harvesting in Microscale with Cavitating Flows

et al. 2017

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Energy harvesting from thermal energy has been widely exploited to achieve energy savings and clean technologies. In this research, a new cost-effective and environment-friendly solution is proposed for the growing individual energy needs thanks to the energy application of cavitating flows. With the aid of cavitating jet flows from microchannel configurations of different sizes, it is shown that significant temperature rise (as high as 5.7 °C) can be obtained on the surface of the thin plate. The obtained heat energy could be integrated to a thermoelectric power generator, which can be used as a power resource for consumer devices, such as cell phones and laptops. To explore the difference in the temperature rise with different microtube diameters, namely, 152, 256, 504, and 762 μm, and also with different upstream pressures of 10, 20, 40, and 60 bar, the cavitation flow patterns are captured and analyzed using an advanced high-speed visualization system. The analysis of the captured data showed that different flow patterns exist for different diameters of the microtubes, including a pattern shift from micro- to macroscale, which accompanied the pattern of temporal results very well.

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Section: Introductionmentioning

confidence: 95%

Energy Harvesting in Microscale with Cavitating Flows

et al. 2017

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“…However, choking cavitation was observed to be independent of any pressure or velocity scale effects. Ghorbani et al [11] studied the cavitating flows between the micro-and macro-scale channels, and results showed that the pressure profile and vapor phase distribution exhibited different features. The static pressure dropped to negative values (tensile stress) in micro-channels, while the minimum static pressure in mini-channels was found to be equal to vapor saturation pressure.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Cavitation Characteristics of Nano-Fluid and Deionized Water in Micro-Channels

Liu

Zhou

et al. 2020

Micromachines

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Hydrodynamic cavitation has been widely applied in micro-fluidic systems. Cavitating flow characteristics are closely related to the fluid properties. In this paper, the cavitation characteristics of Cu nano-fluid in micro-channels were numerically investigated and compared with those of the deionized (DI) water. The mathematical model was verified by comparing the numerical results with the experiment observation. The curved orifice (R = 0.3 mm) was found to have the highest efficiencies of cavitation for both fluids. With the increase of inlet pressure, cavitating jet lengths of the two fluids significantly increased. While, the cavitating jet length of the nano-fluid was shorter than that of the DI water at the same inlet pressure. The cavitation inception number of the DI water and nano-fluid were approximately 0.061 and 0.039, respectively. The results indicate that the nano-particles played negative effects on the cavitation inception. In addition, with the decrease of outlet pressure, the cavitation strength gradually increased and the mass flow rate remained nearly unchanged at the same time.

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“…The LES method [18,19] uses low-pass filtering on the Navier-Stokes equation to reduce the solution on the space and time scales, thereby directly solving large-scale vortices in turbulent flow, and making model assumptions on the motion of small-scale vortices. The calculation accuracy of the LES method is high [20,21]. Although a large amount of calculation resources is still required, it is also increasingly used in actual engineering calculations.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Turbulence Model Influence on the Numerical Simulation of Cavitating Flow with Emphasis on Temperature Effect

et al. 2020

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The aim of this paper is to investigate the influence of different turbulence models (k−ε, RNG k−ε, and SST k−ω) on the numerical simulation of cavitating flow in thermosensitive fluid. The filter-based model and density correction method were employed to correct the turbulent viscosity of the three turbulence models. Numerical results obtained were compared to experimental ones which were conducted on the NACA0015 hydrofoil at different temperatures. The applicability of the numerical solutions of different turbulence model was studied in detail. The modified RNG k−ε model has higher accuracy in the calculation of cavitating flow at different temperatures.

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Cavitating nozzle flows in micro- and minichannels under the effect of turbulence

Cited by 26 publications

References 25 publications

Energy Harvesting in Microscale with Cavitating Flows

Energy Harvesting in Microscale with Cavitating Flows

A Comparative Study of Cavitation Characteristics of Nano-Fluid and Deionized Water in Micro-Channels

Evaluation of the Turbulence Model Influence on the Numerical Simulation of Cavitating Flow with Emphasis on Temperature Effect

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