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Sun X, Xia G, You W, Jia X, Manickam S, Tao Y, Zhao S, Yoon JY, Xuan X. Effect of the arrangement of cavitation generation unit on the performance of an advanced rotational hydrodynamic cavitation reactor. ULTRASONICS SONOCHEMISTRY 2023; 99:106544. [PMID: 37544171 PMCID: PMC10432248 DOI: 10.1016/j.ultsonch.2023.106544] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/08/2023]
Abstract
Hydrodynamic cavitation (HC) is widely considered a promising process intensification technology. The novel advanced rotational hydrodynamic cavitation reactors (ARHCRs), with considerably higher performance compared with traditional devices, have gained increasing attention of academic and industrial communities. The cavitation generation unit (CGU), located on the rotor and/or stator of an ARHCR, is utilized to generate cavitation and consequently, its geometrical structure is vital for the performance. The present work studied, for the first time, the effect of the arrangement of CGU on the performance of a representative ARHCR by employing computational fluid dynamics based on the "simplified flow field" strategy. The effect of CGU arrangement, which was neglected in the past, was evaluated: radial offset distance (c), intersection angle (ω), number of rows (N), circumferential offset angle (γ), and radial spacing (r). The results indicate that the CGU, with an arrangement of a low ω and moderate c, N, γ, and r, performed the highest cavitation efficiency. The corresponding reasons were analyzed by combining the flow field and cavitation pattern. Moreover, the results also exposed a weakness of the "simplified flow field" strategy which may induce the unfavorable "sidewall effect" and cause false high-pressure region. The findings of this work may provide a reference value to the design of ARHCRs.
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Affiliation(s)
- Xun Sun
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China.
| | - Gaoju Xia
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China
| | - Weibin You
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China
| | - Xiaoqi Jia
- Key Laboratory of Fluid Transmission Technology of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Sivakumar Manickam
- Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan BE1410, Brunei Darussalam
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
| | - Shan Zhao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Joon Yong Yoon
- Department of Mechanical Engineering, BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan 15588, Republic of Korea
| | - Xiaoxu Xuan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China
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Min Oo Y, Somnuk K. Investigation of free fatty acid reduction from mixed crude palm oil using 3D-printed rotor-stator hydrodynamic cavitation: An experimental study of geometric characteristics of the inner hole. ULTRASONICS SONOCHEMISTRY 2023; 98:106472. [PMID: 37348259 PMCID: PMC10314289 DOI: 10.1016/j.ultsonch.2023.106472] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/22/2023] [Accepted: 06/06/2023] [Indexed: 06/24/2023]
Abstract
A continuous esterification process is employed to decrease the free fatty acid (FFA) concentration of FFA-rich mixed crude palm oil. Both optimal and recommended conditions are determined for the esterification reaction conditions and the geometry of the 3D-printed rotor design in the rotor-stator hydrodynamic cavitation reactor. This study is primarily concerned with the effect of the cavitation device configuration, especially the rotor design, on FFA reduction. Instead of conventional spherical or cylindrical drilled holes, a point angle cone-shaped hole is used to create cavities over the rotor surface. These point angles are adjusted to clarify their effect on FFA reduction. The response surface methodology is applied to determine the optimal concentrations of methanol and sulfuric acid, rotor speed, hole diameter and depth, and cone point angle. The recommended conditions are 20.8 wt% methanol, 2.6 wt% sulfuric acid, 3000 rpm, 5 mm hole diameter, 5 mm hole depth, and 110°, respectively. Under this configuration, the FFA content is reduced from 12.014 wt% to around 1 wt%. A maximum yield of 97.34 vol% esterified oil is obtained through a completed phase separation step, and 93.31 vol% pure oil is collected after the cleansing step. The recommended conditions result in reduced chemical usage, cheaper FFA reduction, and lower environmental impact. This creative rotor design effectively improves our understanding of the geometry of the cavitation device, thus enhancing the cavitation effect in industrial operations.
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Affiliation(s)
- Ye Min Oo
- Department of Mechanical and Mechatronics Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
| | - Krit Somnuk
- Department of Mechanical and Mechatronics Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand; Energy Technology Research Center, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand.
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Li L, Niu Y, Wei G, Manickam S, Sun X, Zhu Z. Investigation of cavitation noise using Eulerian-Lagrangian multiscale modeling. ULTRASONICS SONOCHEMISTRY 2023; 97:106446. [PMID: 37224639 DOI: 10.1016/j.ultsonch.2023.106446] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 05/10/2023] [Accepted: 05/16/2023] [Indexed: 05/26/2023]
Abstract
We have employed the large eddy simulation (LES) approach to investigate the cavitation noise characteristics of an unsteady cavitating flow around a NACA66 (National Advisory Committee for Aeronautics) hydrofoil by employing an Eulerian-Lagrangian based multiscale cavitation model. A volume of fluid (VOF) method simulates the large cavity, whereas a Lagrangian discrete bubble model (DBM) tracks the small bubbles. Meanwhile, noise is determined using the Ffowcs Williams-Hawkings equation (FW-H). Eulerian-Lagrangian analysis has shown that, in comparison to VOF, it is more effective in revealing microscopic characteristics of unsteady cavitating flows, including microscale bubbles, that are unresolvable around the cloud cavity, and their impact on the flow field. It is also evident that its evolution of cavitation features on the hydrofoil is more consistent with the experimental observations. The frequency of the maximum sound pressure level corresponds to the frequency of the main cavity shedding for the noise characteristics. Using the Eulerian-Lagrangian method to predict the noise signal, results show that the cavitation noise, generated by discrete bubbles due to their collapse, is mainly composed of high-frequency signals. In addition, the frequency of cavitation noise induced by discrete microbubbles is around 10 kHz. A typical characteristic of cavitation noise, including two intense pulses during the collapsing of the cloud cavity, is described, as well as the mechanisms that underlie these phenomena. The findings of this work provide for a fundamental understanding of cavitation and serve as a valuable reference for the design and intensification of hydrodynamic cavitation reactors.
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Affiliation(s)
- Linmin Li
- Key Laboratory of Fluid Transmission Technology of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Yabiao Niu
- Key Laboratory of Fluid Transmission Technology of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Guolai Wei
- Key Laboratory of Fluid Transmission Technology of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Sivakumar Manickam
- Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Jalan Tungku Link Gadong, Bandar Seri Begawan BE1410, Brunei Darussalam
| | - Xun Sun
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China.
| | - Zuchao Zhu
- Key Laboratory of Fluid Transmission Technology of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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Castro-Muñoz R, Boczkaj G, Jafari SM. The role of hydrodynamic cavitation in tuning physicochemical properties of food items: A comprehensive review. Trends Food Sci Technol 2023. [DOI: 10.1016/j.tifs.2023.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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A Review on Rotary Generators of Hydrodynamic Cavitation for Wastewater Treatment and Enhancement of Anaerobic Digestion Process. Processes (Basel) 2023. [DOI: 10.3390/pr11020514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
The issue of ever-increasing amounts of waste activated sludge (WAS) produced from biological wastewater treatment plants (WWTPs) is pointed out. WAS can be effectively reduced in the anaerobic digestion (AD) process, where methanogens break down organic matter and simultaneously produce biogas in the absence of oxygen, mainly methane and CO2. Biomethane can then be effectively used in gas turbines to produce electricity and power a part of WWTPs. Hydrodynamic cavitation (HC) has been identified as a potential technique that can improve the AD process and enhance biogas yield. Rotary generators of hydrodynamic cavitation (RGHCs) that have gained considerable popularity due to their promising results and scalability are presented. Operation, their underlying mechanisms, parameters for performance evaluation, and their division based on geometry of cavitation generation units (CGUs) are presented. Their current use in the field of wastewater treatment is presented, with the focus on WAS pre/treatment. In addition, comparison of achieved results with RGHCs relevant to the enhancement of AD process is presented.
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Studies in instant water disinfection using natural oils. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Sun X, You W, Wu Y, Tao Y, Yoon JY, Zhang X, Xuan X. Hydrodynamic Cavitation: A Novel Non-Thermal Liquid Food Processing Technology. Front Nutr 2022; 9:843808. [PMID: 35308268 PMCID: PMC8931495 DOI: 10.3389/fnut.2022.843808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 01/24/2022] [Indexed: 12/02/2022] Open
Abstract
Hydrodynamic cavitation (HC), as a novel non-thermal processing technology, has recently shown unique effects on the properties of various liquid foods. The extreme conditions of pressure at ~500 bar, local hotspots with ~5,000 K, and oxidation created by HC can help obtain characteristic products with high quality and special taste. Moreover, compared with other emerging non-thermal approaches, the feature of the HC phenomenon and its generation mechanism helps determine that HC is more suitable for industrial-scale processing. This mini-review summarizes the current knowledge of the recent advances in HC-based liquid food processing. The principle of HC is briefly introduced. The effectiveness of HC on the various physical (e.g., particle size, viscosity, temperature, and stability), chemical (nutrition loss), and biological characteristics (microorganism inactivation) of various liquid foods are evaluated. Finally, several recommendations for future research on the HC technique are provided.
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Affiliation(s)
- Xun Sun
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan, China
- National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan, China
- Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Weibin You
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan, China
- National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan, China
| | - Yue Wu
- School of Chemistry, The University of Melbourne, Melbourne, VIC, Australia
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Joon Yong Yoon
- Department of Mechanical Engineering, BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan, South Korea
| | - Xinyan Zhang
- National Engineering Laboratory for Reducing Emissions From Coal Combustion, School of Energy and Power Engineering, Shandong University, Jinan, China
| | - Xiaoxu Xuan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan, China
- National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan, China
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Sun X, Liu S, Zhang X, Tao Y, Boczkaj G, Yoon JY, Xuan X. Recent advances in hydrodynamic cavitation-based pretreatments of lignocellulosic biomass for valorization. BIORESOURCE TECHNOLOGY 2022; 345:126251. [PMID: 34728352 DOI: 10.1016/j.biortech.2021.126251] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
Recently, the hydrodynamic cavitation (HC)-based pretreatment has shown high effectiveness in laboratories and even in industrial productions for conversion of lignocellulosic biomass (LCB) into value-added products. The pretreatment capability derives from the extraordinary conditions of pressures at ∼500 bar, local hotspots with ∼5000 K, and oxidation (hydroxyl radicals) created by HC at room conditions. To promote this emerging technology, the present review summarizes the recent advances in the HC-based pretreatment of LCB. The principle of HC including the sonochemical effect and hydrodynamic cavitation reactor is introduced. The effectiveness of HC on the delignification of LCB as well as subsequent fermentation, paper production, and other applications is evaluated. Several key operational factors (i.e., reaction environment, duration, and feedstock characteristics) in HC pretreatments are discussed. The enhancement mechanism of HC including physical and chemical effects is analyzed. Finally, the perspectives on future research on the HC-based pretreatment technology are highlighted.
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Affiliation(s)
- Xun Sun
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, PR China.
| | - Shuai Liu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, PR China
| | - Xinyan Zhang
- National Engineering Laboratory for Reducing Emissions from Coal Combustion, School of Energy and Power Engineering, Shandong University, Jinan 250061, PR China
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Grzegorz Boczkaj
- Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk 80-233, Poland
| | - Joon Yong Yoon
- Department of Mechanical Engineering, Hanyang University, Ansan 15588, Republic of Korea
| | - Xiaoxu Xuan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, PR China
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Agarkoti C, Thanekar PD, Gogate PR. Cavitation based treatment of industrial wastewater: A critical review focusing on mechanisms, design aspects, operating conditions and application to real effluents. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 300:113786. [PMID: 34649311 DOI: 10.1016/j.jenvman.2021.113786] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/28/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Acoustic cavitation (AC) and hydrodynamic cavitation (HC) coupled with advanced oxidation processes (AOPs) are prominent techniques used for industrial wastewater treatment though most studies have focused on simulated effluents. The present review mainly focuses on the analysis of studies related to real industrial effluent treatment using acoustic and hydrodynamic cavitation operated individually and coupled with H2O2, ozone, ultraviolet, Fenton, persulfate and peroxymonosulfate, and other emerging AOPs. The necessity of using optimum loadings of oxidants in the various AOPs for obtaining maximum COD reduction of industrial effluent have been demonstrated. The review also presents critical analysis of designs of various HCRs that have been or can be used for the treatment of industrial effluents. The impact of operating conditions such as dilution, inlet pressure, ultrasonic power, pH, and operating temperature have been also discussed. The economic aspects of the industrial effluent treatment have been analyzed. HC can be considered as cost-efficient approach compared to AC on the basis of the lower operating costs and better transfer efficiencies. Overall, HC combined with AOPs appears to be an effective treatment strategy that can be successfully implemented at industrial-scale of operation.
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Affiliation(s)
- C Agarkoti
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai, 40019, India
| | - P D Thanekar
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai, 40019, India
| | - P R Gogate
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai, 40019, India.
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Sun X, Yang Z, Wei X, Tao Y, Boczkaj G, Yoon JY, Xuan X, Chen S. Multi-objective optimization of the cavitation generation unit structure of an advanced rotational hydrodynamic cavitation reactor. ULTRASONICS SONOCHEMISTRY 2021; 80:105771. [PMID: 34689065 PMCID: PMC8551246 DOI: 10.1016/j.ultsonch.2021.105771] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/10/2021] [Accepted: 09/24/2021] [Indexed: 05/12/2023]
Abstract
Hydrodynamic cavitation (HC) has been widely considered a promising technique for industrial-scale process intensifications. The effectiveness of HC is determined by the performance of hydrodynamic cavitation reactors (HCRs). The advanced rotational HCRs (ARHCRs) proposed recently have shown superior performance in various applications, while the research on the structural optimization is still absent. The present study, for the first time, identifies optimal structures of the cavitation generation units of a representative ARHCR by combining genetic algorithm (GA) and computational fluid dynamics, with the objectives of maximizing the total vapor volume, Vvapor , and minimizing the total torque of the rotor wall, M→z . Four important geometrical factors, namely, diameter (D), interaction distance (s), height (h), and inclination angle (θ), were specified as the design variables. Two high-performance fitness functions for Vvapor and M→z were established from a central composite design with 25 cases. After performing 10,001 simulations of GA, a Pareto front with 1630 non-dominated points was obtained. The results reveal that the values of s and θ of the Pareto front concentrated on their lower (i.e., 1.5 mm) and upper limits (i.e., 18.75°), respectively, while the values of D and h were scattered in their variation regions. In comparison to the original model, a representative global optimal point increased the Vvapor by 156% and decreased the M→z by 14%. The corresponding improved mechanism was revealed by analyzing the flow field. The findings of this work can strongly support the fundamental understanding, design, and application of ARHCRs for process intensifications.
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Affiliation(s)
- Xun Sun
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China.
| | - Ze Yang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China.
| | - Xuesong Wei
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China.
| | - Yang Tao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
| | - Grzegorz Boczkaj
- Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk 80-233, Poland.
| | - Joon Yong Yoon
- Department of Mechanical Engineering, Hanyang University, Ansan 15588, Republic of Korea.
| | - Xiaoxu Xuan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China.
| | - Songying Chen
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, Shandong University, Jinan 250061, China.
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Application of Thermal and Cavitation Effects for Heat and Mass Transfer Process Intensification in Multicomponent Liquid Media. ENERGIES 2021. [DOI: 10.3390/en14237996] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this paper, the authors consider the processes of dynamic interaction between the boiling particles of the dispersed phase of the emulsion leading to the large droplet breakup. Differences in the consideration of forces that determine the breaking of non-boiling and boiling droplets have been indicated in the study. They have been determined by the possibility of using the model to define the processes of displacement, deformation, or fragmentation of the inclusion of the dispersed phase under the influence of a set of neighboring particles. The dynamics of bubbles in a compressible liquid with consideration for interfacial heat and mass transfer has also been analyzed in the paper. The effect of standard and system parameters on the intensity of cavitation processes is considered. Physical transformations during the cavitation treatment of liquid are caused not only by shock waves and radiated pressure pulses but also by extreme thermal effects. At the stage of ultimate bubble compression, vapor inside the bubble and the liquid in its vicinity transform into the supercritical fluid state. The model analyzes microflow features in the inter-bubble space and quantitatively calculates local values of the velocity and pressure fields, as well as dynamic effects.
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