Effect of bubble-bubble interaction in Cu−Al2O3/H2O hybrid nanofluids during multibubble growth process

This paper scrutinizes the nonlinear multibubble model with considering bubble-bubble (BB) interaction in Cu−Al2O3/water hybrid nanofluid over the vapour bubble radius in Newtonian mediums. Firstly, we present the derivation of the extended Rayleigh-Plesset (ERP) equation of multibubble under the effect of BB interaction in hybrid nanofluids based on the Navier-Stokes equation. The model is formulated by the continuity equation, the ERP in the hybrid nanofluids and the relations of thermophysical features in mono and hybrid nanofluids. The ERP equation is transformed into an ordinary differential equation using the non-dimensions variables methodology, which is then solved analytically using the modified Plesset-Zwick method. In addition, the current model presents the influence of BB interactions on growth process of multibubble in Cu−Al2O3/H2O hybrid nanofluids. As a result, the impact of increasing of the number of bubbles “n” and BB interactions in a hybrid nanofluid, at n=1,2,3 on the growth process are investigated. Moreover, it is found that the growth process of multibubble dynamics in hybrid nanofluid increases when the distance between BB interaction and volume concentration decrease. The growth of multibubble dynamics in Cu−Al2O3/water hybrid nanofluid is less than in the cases of water-base fluid and Al2O3/water nanofluids. Additionally, vapour bubble radii in the current study give a good agreement and lower behavior if compared with the prior investigations. © 202

INVESTIGATION THE PRESSURE RELAXATION TIME OF N-DIMENSIONAL SPHERICAL BUBBLE WITHIN Fe3O4- NANOFLUID

The pressure relaxation time[1-3] is a method of evaluation of a time constant that de-scribes relaxation heat exchange between vapour bubble and superheated liquid at saturation temperature and a non-steady temperature field

Effect of Heat Transfer on the Growing Bubble with the Nanoparticles/Water Nanofluids in Turbulent Flow

This paper is devoted to study the effect of heat transfer on the temperature distribution in a superheated liquid during the growth of vapour bubbles immersed in different types of nanoparticles/water nanofluids between two-phase turbulent flow. The mathematical model is formulated and solved analytically depending on Scriven’s theory and using the modification of the method of the similarity parameters between two finite boundaries. The characteristics of vapour bubble growth and temperature distribution are obtained by using the thermo-physical properties of nanoparticles nanofluids. The results indicate that the nanoparticle volume concentration reduces the bubble growth process under the effect of heat transfer. The better agreements are achieved, for bubble dynamics in turbulent nanofluid using the appropriate numerical and theoretical data for the values of concentration rate of nanoparticles χ=0,0.2,0.4. The temperature distribution surrounding the regime of bubble growth in pure water is more intensive than in other cases of Al2O3/H2O, Fe3O4/H2O and CuO/H2O nanofluids in turbulent flow. A Comparison of the current solution with previous works is carried out and discussed. © 2021. All Rights Reserved

Heat exchange within the surrounding biological tissue during magnetic hyperthermia

The paper deals with mathematical modeling and theoretical study of the heat distribution within the surrounding biological tissue during the effect of the magnetic hyperthermia. The mathematical model is formulated and solved numerically by using the finite difference method. The intensity of heat production is used in the present model. The obtained results allow predicting the temperature change in tumor as well as in the surrounding tissue depending on intensity of the tumor heating. © 2020 International Information and Engineering Technology Association.Russian Foundation for Fundamental Investigations, RFFI: 18-08-00178, 19-52-45001Ministry of Science and Higher Education of the Russian FederationThis paper has been supported by RFFI, grants 18-08-00178, 19-52-45001 and the state program of the Ministry of Science and Higher Education of the Russian Federation (theme “Magnet” and Contract No. 02.A03.21.006)

Effect of interparticle interaction on magnetic hyperthermia: Homogeneous spatial distribution of the particles

The paper deals with the theoretical study of the effect of magnetic interparticle interaction on magnetic hyperthermia, produced by the particles under the action of a linearly polarized oscillating field. The particles are homogeneously distributed and immobilized in a rigid medium. The supposed size of the magnetite particles is about 20-30 nm. For these particles, the characteristic time of the Neel remagnetization is much longer than the time of observation. This is why we concluded that the dissipation occurs as a result of the particle magnetic moment oscillation in the pit of energy of magnetic anisotropy. This article is part of the theme issue 'Heterogeneous materials: Metastable and non-ergodic internal structures'. ©2019 The Author(s)Published by the Royal Society

A Study of Easy Magnetization Axes of Ferro-nanoparticles on Magnetic Hyperthermia

This work deals with theoretical approach and mathematical modeling of hyperthermia effect by single-domain ferro-nanoparticles. The magnetic particles have the Neel relaxation particles of the easy magnetization axes. The system is happened under external magnetic field. Two situations of systems, system of approximation of non-interaction chaotic particles like single particle and system of chain-like two particles are considered into account whereas these particles are in strong magnetic anisotropy. Our analysis shows the chain of particles with strong magnetic anisotropy weakens the thermal effect of hyperthermia under the effect of easy magnetization axes of ferro-nanoparticles. © 2020 American Institute of Physics Inc.. All rights reserved.This paper has been supported by RFFI, grants 18-08-00178, 19-52-45001 and the state program of the Ministry of Science and Higher Education of the Russian Federation (theme “Magnet” and Contract No. 02.A03.21.006)

Growth of N-dimensional Spherical Bubble within Viscous, Superheated Liquid Analytical Solution

In this paper, we present the study of the behavior of spherical bubble in N-di-mensions fluid. The fluid is a mixture of vapor and superheated liquid. The math-ematical model is formulated in N-dimensions fluid on the basis of continuity and momentum equations, and solved its analytically. The variable viscosity is taken into an account problem. The obtained results show that the radius of bubble in-creases with the decreasing of the value of N-dimensions. © 2021 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This is an open access article distributed under the CC BY-NC-ND 4.0 terms and conditions

On the theory of magnetic hyperthermia: Clusterization of nanoparticles

Experiments show that clusters consisting of nano-sized ferromagnetic particles strongly affect the intensity of heat production during magnetic hyperthermia. In this paper, a theoretical study and mathematical modelling of the heat production by clusters of single-domain ferromagnetic particles, immobilized in a host medium, are presented. Two situations of strong and weak magnetic anisotropy of the particles are considered. Our results show that, in the case of strong anisotropy, the clusterization weakens the thermal effect, whereas in the case of weak anisotropy it enhances it. © 2020 The Author(s) Published by the Royal Society. All rights reserved.Ministry of Education and Science of the Russian Federation, Minobrnauka: FEUZ-2020-0051Russian Foundation for Basic Research, RFBR: 18-08-00178, 20-02-00022, 19-52-45001Data accessibility. This article has no additional data. Competing interests. We declare we have no competing interests. Funding. This work has been done with the financial support of a programme of the Ministry of Education and Science of the Russian Federation, projects 02.A03.21.0006 and FEUZ-2020-0051, as well as of the Russian Foundation of Basic Research, projects 18-08-00178, 19-52-45001 and 20-02-00022

Analysis of doublet bubble dynamics near a rigid wall in ferroparticle nanofluids

This study aims to characterize the interaction of doublet bubbles growing near a solid wall in ferroparticle nanofluids. Accordingly, we analyzed the behavior of spherical bubbles near a rigid wall considering liquid compressibility of suspended ferro-nanoparticles. In addition to the interaction effect between two bubbles, we considered the rigid wall forces and thermophysical configurations of the particles in nanofluids to understand the bubble growth. The equation of motion of the doublet bubbles was formulated based on the continuity equation, Euler equation, wave equation, and thermophysical configurations of the particles in nanofluids. Subsequently, the developed model was analytically solved by modifying the Plesset-Zwick technique. Throughout the bubble growth, we examined the thermal effects on the cavitation bubble dynamics, such as the distance between the interacting bubbles, vertical distance between the bubble center and rigid wall, and ferro-nanoparticle volume concentration. The analysis results revealed that the bubble growth was directly proportional to the Jacob number and thermal diffusivity, and inversely proportional to the distance between the boundary rigid wall and bubble center. Furthermore, it can be deduced from the results that the presence of the wall significantly influenced the bubble growth and made a significant deviation between the moving velocities of the interfaces both near and far from the wall. Ultimately, the phenomenon was physically interpreted based on the theory of bubble dynamics, and the water pressure induced by the bubble growth was estimated. The results were well aligned with the theoretical and experimental results from previous studies. © 2022 Published by Elsevier Ltd.Japan Society for the Promotion of Science, KAKEN: 18K03942We would like to thank referees for their valuable comments and suggestions, and Editage ( www.editage.com ) for English language editing. Further, this work was partially carried out with the aid of the JSPS KAKENHI ( 18K03942 )

Study of the Biotissue Histotripsy Based on Microbubble Dynamics in Hydrogels

Biotissue histotripsy is a technique that uses sound waves to create cavitation in tissue. High-intensity ultrasonic waves perform the production of small vacuum microbubbles or microcavities in the liquid during the low-pressure cycle