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Fomitchev-Zamilov M. Observation of neutron emission during acoustic cavitation of deuterated titanium powder. Sci Rep 2024; 14:11517. [PMID: 38769316 PMCID: PMC11106313 DOI: 10.1038/s41598-024-62055-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 05/13/2024] [Indexed: 05/22/2024] Open
Abstract
Possibility of nuclear reactions in solid state is intriguing for two reasons: (1) It provides a means of studying nuclear processes in conditions that are much different from traditional plasma-filled reactors or particle accelerators; (2) it dramatically lowers the cost and complexity of the experimental setups by eliminating the highly capital intensive components such as plasma/vacuum systems and particle accelerators. In this article we report the observation of neutron emission coincident with acoustic cavitation of deuterated titanium powder suspended in mineral oil. The resulting neutron emission was detected using an assembly of 3He proportional neutron counters. The peak neutron count rate was in excess of 6500 CPM, more than 10,000 times in excess of background. The observed neutron emission was coincident with the application of acoustic influence. The neutrons were present only when secondary acoustic waves originating from the complex bubble interactions inside the reactor constructively interfered resulting in massive, sharp pressure peaks on the order of a few thousand psi. We were able to sustain the neutron production for several hours and repeated the experiment multiple times under various conditions. We hypothesize that the observed neutrons originate from nuclear fusion of deuterium ions dissolved in titanium lattice due to the mechanical action of the impinging cavitation jets, although other processes (such as spallation) still need to be ruled out.
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Guo C, Liu J, Li X, Yang S. Effect of cavitation bubble on the dispersion of magnetorheological polishing fluid under ultrasonic preparation. ULTRASONICS SONOCHEMISTRY 2021; 79:105782. [PMID: 34649163 PMCID: PMC8517386 DOI: 10.1016/j.ultsonch.2021.105782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 09/28/2021] [Accepted: 10/04/2021] [Indexed: 05/31/2023]
Abstract
In the ultrasonic dispersion process, the ultrasonic cavitation effect can seriously affect the dispersion efficiency of magnetorheological polishing fluid (MRPF), but the mechanism remains unclear now. Through considering the continuity equation and Vand viscosity equation of the suspension, a revised cavitation bubble dynamic model in the MRPF was developed and calculated. The effects of presence or absence of solid particles, the volume fraction of solid particles, and viscosity on the cavitation bubble motion characteristics in the MRPF were discussed. Settlement experiments of the MRPF under ultrasonic and mechanical dispersion were observed. Analysis of particle dispersion is made by trinocular biomicroscope and image processing of the microscopic morphology of the MRPF. The results show that the high volume fraction of carbonyl iron particle (CIP) will significantly weaken the cavitation effect, and the low volume fraction of green silicon carbide (GSC) has a negligible effect on the cavitation effect in the MRPF. When the liquid viscosity is greater than or equal to 0.1 Pa·s, it is inconvenient to produce micro-jets in the MRPF. The sedimentation rate of the MRPF prepared by ultrasonic dispersion is lower than mechanical dispersion when the volume fraction of CIP is between 1% and 25%. The dispersion ratio under ultrasonic dispersion is lower than that under mechanical dispersion. The experimental results fit the simulation well. It offers a theoretical basis for exploring the ultrasonic cavitation effect in the industrial application of the MRPF.
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Affiliation(s)
- Ce Guo
- Shanxi Key Laboratory of Precision Machining, College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, 030024 Taiyuan, China; Taiyuan Heavy Mechinery Group Co., LTD, 030024 Taiyuan, China.
| | - Jing Liu
- Shanxi Key Laboratory of Precision Machining, College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, 030024 Taiyuan, China
| | - Xiuhong Li
- Shanxi Key Laboratory of Precision Machining, College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, 030024 Taiyuan, China
| | - Shengqiang Yang
- Shanxi Key Laboratory of Precision Machining, College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, 030024 Taiyuan, China
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Soyama H. Luminescence intensity of vortex cavitation in a Venturi tube changing with cavitation number. ULTRASONICS SONOCHEMISTRY 2021; 71:105389. [PMID: 33221624 PMCID: PMC7786618 DOI: 10.1016/j.ultsonch.2020.105389] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/15/2020] [Accepted: 10/30/2020] [Indexed: 05/27/2023]
Abstract
Hydrodynamic cavitation in a Venturi tube produces luminescence, and the luminescence intensity reaches a maximum at a certain cavitation number, which is defined by upstream pressure, downstream pressure, and vapor pressure. The luminescence intensity of hydrodynamic cavitation can be enhanced by optimizing the downstream pressure at a constant upstream pressure condition. However, the reason why the luminescence intensity increases and then decreases with an increase in the downstream pressure remains unclear. In the present study, to clarify the mechanism of the change in the luminescence intensity with cavitation number, the luminescence produced by the hydrodynamic cavitation in a Venturi tube was measured, and the hydrodynamic cavitation was precisely observed using high-speed photography. The sound velocity in the cavitating flow field, which affects the aggressive intensity of the cavitation, was evaluated. The collapse of vortex cavitation was found to be closely related to the luminescence intensity of the hydrodynamic cavitation. A method to estimate the luminescence intensity of the hydrodynamic cavitation considering the sound velocity was developed, and it was demonstrated that the estimated luminescence intensity agrees well with the measured luminescence intensity.
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Affiliation(s)
- Hitoshi Soyama
- Department of Finemechanics, Tohoku University, 6-6-01 Aramaki, Aoba-ku, Sendai 980-8579, Japan.
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Abstract
When a high-speed water jet is injected into water through a nozzle, cavitation is generated in the nozzle and/or shear layer around the jet. A jet with cavitation is called a “cavitating jet”. When the cavitating jet is injected into a surface, cavitation is collapsed, producing impacts. Although cavitation impacts are harmful to hydraulic machinery, impacts produced by cavitating jets are utilized for cleaning, drilling and cavitation peening, which is a mechanical surface treatment to improve the fatigue strength of metallic materials in the same way as shot peening. When a cavitating jet is optimized, the peening intensity of the cavitating jet is larger than that of water jet peening, in which water column impacts are used. In order to optimize the cavitating jet, an understanding of the instabilities of the cavitating jet is required. In the present review, the unsteady behavior of vortex cavitation is visualized, and key parameters such as injection pressure, cavitation number and sound velocity in cavitating flow field are discussed, then the estimation methods of the aggressive intensity of the jet are summarized.
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Wilhelmsen Ø, Trinh TT, Lervik A. Temperature anisotropy at equilibrium reveals nonlocal entropic contributions to interfacial properties. Phys Rev E 2018; 97:012126. [PMID: 29448485 DOI: 10.1103/physreve.97.012126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/07/2022]
Abstract
Density gradient theory for fluids has played a key role in the study of interfacial phenomena for a century. In this work, we revisit its fundamentals by examining the vapor-liquid interface of argon, represented by the cut and shifted Lennard-Jones fluid. The starting point has traditionally been a Helmholtz energy functional using mass densities as arguments. By using rather the internal energy as starting point and including the entropy density as an additional argument, following thereby the phenomenological approach from classical thermodynamics, the extended theory suggests that the configurational part of the temperature has different contributions from the parallel and perpendicular directions at the interface, even at equilibrium. We find a similar anisotropy by examining the configurational temperature in molecular dynamics simulations and obtain a qualitative agreement between theory and simulations. The extended theory shows that the temperature anisotropy originates in nonlocal entropic contributions, which are currently missing from the classical theory. The nonlocal entropic contributions discussed in this work are likely to play a role in the description of both equilibrium and nonequilibrium properties of interfaces. At equilibrium, they influence the temperature- and curvature-dependence of the surface tension. Across the vapor-liquid interface of the Lennard Jones fluid, we find that the maximum in the temperature anisotropy coincides precisely with the maximum in the thermal resistivity relative to the equimolar surface, where the integral of the thermal resistivity gives the Kapitza resistance. This links the temperature anisotropy at equilibrium to the Kapitza resistance of the vapor-liquid interface at nonequilibrium.
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Affiliation(s)
- Øivind Wilhelmsen
- Department of Energy and Process Technology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway and SINTEF Energy Research, NO-7465 Trondheim, Norway
| | - Thuat T Trinh
- Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Anders Lervik
- Department of Chemistry, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
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Lervik A, Wilhelmsen Ø, Trinh TT, Nagel HR. Finite-size and truncation effects for microscopic expressions for the temperature at equilibrium and nonequilibrium. J Chem Phys 2015; 143:114106. [DOI: 10.1063/1.4930540] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Radziuk D, Möhwald H, Suslick K. Single bubble perturbation in cavitation proximity of solid glass: hot spot versus distance. Phys Chem Chem Phys 2014; 16:3534-41. [DOI: 10.1039/c3cp52850b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Flannigan DJ, Suslick KS. Non-Boltzmann Population Distributions during Single-Bubble Sonoluminescence. J Phys Chem B 2013; 117:15886-93. [DOI: 10.1021/jp409222x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- David J. Flannigan
- Department of Chemical
Engineering and Materials Science, University of Minnesota, 421 Washington
Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Kenneth S. Suslick
- Department of Chemistry, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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Hołyst R, Litniewski M, Garstecki P. Collapse of a nanoscopic void triggered by a spherically symmetric traveling sound wave. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:056303. [PMID: 23004859 DOI: 10.1103/physreve.85.056303] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 03/02/2012] [Indexed: 06/01/2023]
Abstract
Molecular-dynamics simulations of the Lennard-Jones fluid (up to 10(7) atoms) are used to analyze the collapse of a nanoscopic bubble. The collapse is triggered by a traveling sound wave that forms a shock wave at the interface. The peak temperature T(max) in the focal point of the collapse is approximately ΣR(0)(a), where Σ is the surface density of energy injected at the boundary of the container of radius R(0) and α ≈ 0.4-0.45. For Σ = 1.6 J/m(2) and R(0) = 51 nm, the shock wave velocity, which is proportional to √Σ, reaches 3400 m/s (4 times the speed of sound in the liquid); the pressure at the interface, which is proportional to Σ, reaches 10 GPa; and T(max) reaches 40,000 K. The Rayleigh-Plesset equation together with the time of the collapse can be used to estimate the pressure at the front of the shock wave.
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Affiliation(s)
- Robert Hołyst
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland.
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Anderson P, Sampathkumar A, Murray TW, Gaitan DF, Glynn Holt R. Optical nucleation of bubble clouds in a high pressure spherical resonator. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 130:3389-3395. [PMID: 22088012 DOI: 10.1121/1.3626161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An experimental setup for nucleating clouds of bubbles in a high-pressure spherical resonator is described. Using nanosecond laser pulses and multiple phase gratings, bubble clouds are optically nucleated in an acoustic field. Dynamics of the clouds are captured using a high-speed CCD camera. The images reveal cloud nucleation, growth, and collapse and the resulting emission of radially expanding shockwaves. These shockwaves are reflected at the interior surface of the resonator and then reconverge to the center of the resonator. As the shocks reconverge upon the center of the resonator, they renucleate and grow the bubble cloud. This process is repeated over many acoustic cycles and with each successive shock reconvergence, the bubble cloud becomes more organized and centralized so that subsequent collapses give rise to stronger, better defined shockwaves. After many acoustic cycles individual bubbles cannot be distinguished and the cloud is then referred to as a cluster. Sustainability of the process is ultimately limited by the detuning of the acoustic field inside the resonator. The nucleation parameter space is studied in terms of laser firing phase, laser energy, and acoustic power used.
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Affiliation(s)
- Phillip Anderson
- Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA.
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Hołyst R, Litniewski M, Garstecki P. Large-scale molecular dynamics verification of the Rayleigh-Plesset approximation for collapse of nanobubbles. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:066309. [PMID: 21230736 DOI: 10.1103/physreve.82.066309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 10/23/2010] [Indexed: 05/30/2023]
Abstract
We report large-scale (10(7) atoms in an 85-nm-wide container) molecular dynamics simulations of collapse of nanoscopic (5-12 nm in diameter) voids in liquid argon. During the collapse the pressure on the liquid side decreases, and this decrease propagates into liquid at the speed of sound. Despite the nonuniform profile of pressure in the liquid the solutions of the Rayleigh-Plesset equation compares well to the measured evolution of the radius of the void and the velocity of the interface. Evaporation of liquid into the void does not affect the dynamics appreciably.
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Affiliation(s)
- Robert Hołyst
- Institute of Physical Chemistry PAS, Warsaw, Poland.
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Levinsen MT. Data collapse of the spectra of water-based stable single-bubble sonoluminescence. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:036323. [PMID: 21230187 DOI: 10.1103/physreve.82.036323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 07/05/2010] [Indexed: 05/30/2023]
Abstract
In the early days of stable single-bubble sonoluminescence, it was strongly debated whether the emission was blackbody radiation or whether the bubble was transparent to its own radiation (volume emission). Presently, the volume emission picture is nearly universally accepted. We present new measurements of spectra with apparent color temperatures ranging from 6000 to 21 000 K. We show through data collapse that within experimental uncertainty, apart from a constant, the spectra of strongly driven stable single-bubble sonoluminescence in water can be written as the product between a universal function of wavelength and a functional form that only depends on wavelength and apparent temperature but has no reference to any other parameter specific to the experimental situation. This remarkable result does question our theoretical understanding of the state of the plasma in the interior of strongly driven stable sonoluminescent bubbles.
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Affiliation(s)
- Mogens T Levinsen
- BioComplexity Laboratory, Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark.
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Xu H, Suslick KS. Molecular emission and temperature measurements from single-bubble sonoluminescence. PHYSICAL REVIEW LETTERS 2010; 104:244301. [PMID: 20867304 DOI: 10.1103/physrevlett.104.244301] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Indexed: 05/14/2023]
Abstract
Single-bubble sonoluminescence (SBSL) spectra in H2O show featureless continuum emission. From an acoustically driven, moving bubble in phosphoric acid (H3PO4), we observe very strong molecular emission from excited OH radicals (∼310 nm), which can be used as a spectroscopic thermometer by fitting the experimental SBSL spectra to the OH A 2Σ+ - X 2Π rovibronic transitions. The observed emission temperature (T(em)) ranges from 6200 to 9500 K as the acoustic pressure (P(a)) varies from 1.9 to 3.1 bar and from 6000 to >10,000 K as the dissolved monatomic gas varies over the series from He to Xe.
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Affiliation(s)
- Hangxun Xu
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Gaitan DF, Tessien RA, Hiller RA, Gutierrez J, Scott C, Tardif H, Callahan B, Matula TJ, Crum LA, Holt RG, Church CC, Raymond JL. Transient cavitation in high-quality-factor resonators at high static pressures. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 127:3456-3465. [PMID: 20550245 DOI: 10.1121/1.3377062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
It is well known that cavitation collapse can generate intense concentrations of mechanical energy, sufficient to erode even the hardest metals and to generate light emissions visible to the naked eye [sonoluminescence (SL)]. Considerable attention has been devoted to the phenomenon of "single bubble sonoluminescence" (SBSL) in which a single stable cavitation bubble radiates light flashes each and every acoustic cycle. Most of these studies involve acoustic resonators in which the ambient pressure is near 0.1 MPa (1 bar), and with acoustic driving pressures on the order of 0.1 MPa. This study describes a high-quality factor, spherical resonator capable of achieving acoustic cavitation at ambient pressures in excess of 30 MPa (300 bars). This system generates bursts of violent inertial cavitation events lasting only a few milliseconds (hundreds of acoustic cycles), in contrast with the repetitive cavitation events (lasting several minutes) observed in SBSL; accordingly, these events are described as "inertial transient cavitation." Cavitation observed in this high pressure resonator is characterized by flashes of light with intensities up to 1000 times brighter than SBSL flashes, as well as spherical shock waves with amplitudes exceeding 30 MPa at the resonator wall. Both SL and shock amplitudes increase with static pressure.
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Affiliation(s)
- D Felipe Gaitan
- Impulse Devices, Inc, 13366 Grass Valley Avenue, Unit H, Grass Valley, California 95945, USA.
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Moshaii A, Imani K, Silatani M. Sonoluminescence radiation from different concentrations of sulfuric acid. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 80:046325. [PMID: 19905454 DOI: 10.1103/physreve.80.046325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 08/17/2009] [Indexed: 05/28/2023]
Abstract
Sonoluminescence (SL) radiation from an argon bubble in water and in different concentrations of sulfuric acid has numerically been studied to quantify the effects of vapor pressure and viscosity of the liquid on cavitation luminescence in a liquid with controllable vapor pressure and viscosity. For the solutions containing the noble gas with low partial pressure (about 4 Torr), it is shown that there exists an optimum acid solution in which both the temperature and the intensity of SL radiation become maximum. The calculations show that the maximum SL radiation is achieved from the solution of around 65% (wt.) H2SO4, which is in agreement with available experimental results.
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Affiliation(s)
- A Moshaii
- Department of Physics, Tarbiat Modares University, Tehran, Iran.
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