Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-08
Rupam Shankar Nath, R. Deka, Himangshu Kumar
This research paper investigates the effects of thermal stratification on unsteady parabolic flow past an infinite vertical plate with chemical reaction. Using the Laplace transform method, analytical solutions are derived to simulate the physical process of the flow. The study considers the effects of thermal stratification on the flow field, as well as the effects of chemical reaction on the velocity, and temperature field. The results of the stratification case are then compared to the case of no stratification of a similar flow field. The results of this research can be used to improve understanding of the unsteady parabolic flow in thermal stratified environments and provide valuable insight into the effects of chemical reactions on the temperature field.
{"title":"The Effect of Thermal Stratification on Unsteady Parabolic Flow past an Infinite Vertical Plate with Chemical Reaction","authors":"Rupam Shankar Nath, R. Deka, Himangshu Kumar","doi":"10.26565/2312-4334-2023-4-08","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-08","url":null,"abstract":"This research paper investigates the effects of thermal stratification on unsteady parabolic flow past an infinite vertical plate with chemical reaction. Using the Laplace transform method, analytical solutions are derived to simulate the physical process of the flow. The study considers the effects of thermal stratification on the flow field, as well as the effects of chemical reaction on the velocity, and temperature field. The results of the stratification case are then compared to the case of no stratification of a similar flow field. The results of this research can be used to improve understanding of the unsteady parabolic flow in thermal stratified environments and provide valuable insight into the effects of chemical reactions on the temperature field.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-40
Sharifa B. Utamuradova, R. Rasulov, V. R. Rasulov, Kamolakhon K. Urinova, K. Fayzullaev
This article discusses studies of size quantization phenomena in zero-, one-, and two-dimensional semiconductor structures. The main attention is paid to the mechanisms of photon-kinetic effects in these structures. Despite many studies of the physical properties of low-dimensional systems of current carriers, the size quantization of energy spectra in narrow-gap semiconductors and the associated photonic-kinetic effects are still insufficiently studied. Therefore, this study focuses on the quantum mechanical study of size quantization in certain cases using Kane's multiband model. The insolvability of the 8×8 matrix Schrödinger equation in the Kane model for a potential well of arbitrary shape is analyzed. The dependence of the energy spectrum on the two-dimensional wave vector is studied for various cases. In particular, the energy spectra for InSb and GaAs semiconductors are considered, depending on the band parameters and the size of the potential well. Conclusions are presented on the analysis of various cases of size quantization in narrow-gap crystals with cubic or tetrahedral symmetry in the three-band approximation. It is shown that the energy spectrum corresponds to a set of size-quantized levels that depend on the Rabi parameter, band gap, and well size. The size-quantized energy spectra of electrons and holes in InSb and GaAs semiconductors are analyzed in a multiband model.
{"title":"To the Theory of Dimensional Quantization in Narrow-Gap Crystals","authors":"Sharifa B. Utamuradova, R. Rasulov, V. R. Rasulov, Kamolakhon K. Urinova, K. Fayzullaev","doi":"10.26565/2312-4334-2023-4-40","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-40","url":null,"abstract":"This article discusses studies of size quantization phenomena in zero-, one-, and two-dimensional semiconductor structures. The main attention is paid to the mechanisms of photon-kinetic effects in these structures. Despite many studies of the physical properties of low-dimensional systems of current carriers, the size quantization of energy spectra in narrow-gap semiconductors and the associated photonic-kinetic effects are still insufficiently studied. Therefore, this study focuses on the quantum mechanical study of size quantization in certain cases using Kane's multiband model. The insolvability of the 8×8 matrix Schrödinger equation in the Kane model for a potential well of arbitrary shape is analyzed. The dependence of the energy spectrum on the two-dimensional wave vector is studied for various cases. In particular, the energy spectra for InSb and GaAs semiconductors are considered, depending on the band parameters and the size of the potential well. Conclusions are presented on the analysis of various cases of size quantization in narrow-gap crystals with cubic or tetrahedral symmetry in the three-band approximation. It is shown that the energy spectrum corresponds to a set of size-quantized levels that depend on the Rabi parameter, band gap, and well size. The size-quantized energy spectra of electrons and holes in InSb and GaAs semiconductors are analyzed in a multiband model.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-44
V. Olefir, Oleksandr Sporov, M. Azarenkov
The article presents the results of the theoretical study of the plasma density axial distribution in a stationary gas discharge sustained by the eigen dipolar wave that propagates in a long cylindrical plasma-metal structure. The discharge structure consists of a column of magnetized non-uniform plasma placed in the metal waveguide of variable radius. The study of the gas discharge is carried out within the framework of the electrodynamic model, in which the main attention is paid to the electrodynamic part of the model. To describe the processes that take place in plasma, the model equations are used. The influence of the metal waveguide inhomogeneity along the structure and the plasma density radial non-uniformity on the phase characteristics of the dipolar wave, its spatial attenuation, the field components radial distribution, the axial distribution of the plasma density sustained by this mode are determined. It is also analysed the condition for the discharge stability and find the regions, where dipolar mode can sustain the stable discharge. The obtained results can be useful for various technological applications.
{"title":"Axial Structure of Gas Discharge Sustained by the Eigen Dipolar Wave of The Metal Waveguide with Varying Radius Filled by Magnetized Nonuniform Plasma","authors":"V. Olefir, Oleksandr Sporov, M. Azarenkov","doi":"10.26565/2312-4334-2023-4-44","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-44","url":null,"abstract":"The article presents the results of the theoretical study of the plasma density axial distribution in a stationary gas discharge sustained by the eigen dipolar wave that propagates in a long cylindrical plasma-metal structure. The discharge structure consists of a column of magnetized non-uniform plasma placed in the metal waveguide of variable radius. The study of the gas discharge is carried out within the framework of the electrodynamic model, in which the main attention is paid to the electrodynamic part of the model. To describe the processes that take place in plasma, the model equations are used. The influence of the metal waveguide inhomogeneity along the structure and the plasma density radial non-uniformity on the phase characteristics of the dipolar wave, its spatial attenuation, the field components radial distribution, the axial distribution of the plasma density sustained by this mode are determined. It is also analysed the condition for the discharge stability and find the regions, where dipolar mode can sustain the stable discharge. The obtained results can be useful for various technological applications.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-38
M. Azarenkov, Oleksii A. Haluza, Alexander V. Gapon, Volodymyr V. Lytvynenko
The aluminum alloys D16, D16AT are widely used as construction materials in the aircraft industry. Questions connected with the enhancement of the properties of the construction elements made of the alloys through surface modification are of great interest now. The objects of the study in our paper are the samples of the aluminum alloy D16AT subjected to irradiation by high-current relativistic electron beams. Leaving aside the material science aspects, in this work we focused on modeling the optical properties of the samples. The problem is relevant because optical methods for surface analysis have become widespread due to their versatility and efficiency. Through the treatment of the preliminary measured ellipsometry data, we obtain the optical constants of the samples and their dispersion in the visible region of wavelength. The method used consists of an approximation of the reflection coefficient calculated from the ellipsometry data by finding the values of the parameters in the model. The last is performed by the least squares method. The reflection coefficient is assumed to correspond to the semibounded uniaxial medium with the optical axis perpendicular to the interface between the medium and the homogeneous and dielectric ambient medium. The dielectric function of the semibounded medium is approximated by the Drude-Lorentz model. The possibility of birefringence of the samples caused by the irradiation with electron beams is discussed.
{"title":"Optical Parameters of Aluminum Alloy Samples Irradiated by High Current Relativistic Electron Beams","authors":"M. Azarenkov, Oleksii A. Haluza, Alexander V. Gapon, Volodymyr V. Lytvynenko","doi":"10.26565/2312-4334-2023-4-38","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-38","url":null,"abstract":"The aluminum alloys D16, D16AT are widely used as construction materials in the aircraft industry. Questions connected with the enhancement of the properties of the construction elements made of the alloys through surface modification are of great interest now. The objects of the study in our paper are the samples of the aluminum alloy D16AT subjected to irradiation by high-current relativistic electron beams. Leaving aside the material science aspects, in this work we focused on modeling the optical properties of the samples. The problem is relevant because optical methods for surface analysis have become widespread due to their versatility and efficiency. Through the treatment of the preliminary measured ellipsometry data, we obtain the optical constants of the samples and their dispersion in the visible region of wavelength. The method used consists of an approximation of the reflection coefficient calculated from the ellipsometry data by finding the values of the parameters in the model. The last is performed by the least squares method. The reflection coefficient is assumed to correspond to the semibounded uniaxial medium with the optical axis perpendicular to the interface between the medium and the homogeneous and dielectric ambient medium. The dielectric function of the semibounded medium is approximated by the Drude-Lorentz model. The possibility of birefringence of the samples caused by the irradiation with electron beams is discussed.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a comprehensive investigation into the DC analog and AC microwave performance of a state-of-the-art T-gate double barrier AlGaN/AlInGaN/GaN MOSHEMT (Metal Oxide Semiconductor High Electron Mobility Transistor) implemented on a 4H-SiC substrate. The study involves meticulous numerical simulations and an extensive comparison with a single barrier design, utilizing the TCAD-Silvaco software. The observed disparity in performance can be attributed to the utilization of double barrier technology, which enhances electron confinement and current density by augmenting the polarization-induced charge during high-frequency operations. Remarkably, when compared to the single barrier design, the double barrier MOSHEMT exhibits a notable 15% increase in drain current, a 5% increase in transconductance, and an elevated breakdown voltage (VBR) of 140 V in E-mode operation. Furthermore, the radio frequency analysis of the double barrier device showcases exceptional performance, setting new records with a maximum oscillation frequency (fmax) of 1.148 THz and a gain cutoff frequency (ft) of 891 GHz. These impressive results obtained through deck-simulation affirm the immense potential of the proposed double barrier AlGaN/AlInGaN/GaN MOSHEMT for future applications in high-power and terahertz frequency domains.
{"title":"Numerical study of T-Gate AlGaN/AlInGaN/GaN MOSHEMT with Single and Double Barrier for THz Frequency Applications","authors":"Amina Noual, Messai Zitouni, Zine-eddine Touati, Okba Saidani, Abderrahim Yousfi","doi":"10.26565/2312-4334-2023-4-27","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-27","url":null,"abstract":"This paper presents a comprehensive investigation into the DC analog and AC microwave performance of a state-of-the-art T-gate double barrier AlGaN/AlInGaN/GaN MOSHEMT (Metal Oxide Semiconductor High Electron Mobility Transistor) implemented on a 4H-SiC substrate. The study involves meticulous numerical simulations and an extensive comparison with a single barrier design, utilizing the TCAD-Silvaco software. The observed disparity in performance can be attributed to the utilization of double barrier technology, which enhances electron confinement and current density by augmenting the polarization-induced charge during high-frequency operations. Remarkably, when compared to the single barrier design, the double barrier MOSHEMT exhibits a notable 15% increase in drain current, a 5% increase in transconductance, and an elevated breakdown voltage (VBR) of 140 V in E-mode operation. Furthermore, the radio frequency analysis of the double barrier device showcases exceptional performance, setting new records with a maximum oscillation frequency (fmax) of 1.148 THz and a gain cutoff frequency (ft) of 891 GHz. These impressive results obtained through deck-simulation affirm the immense potential of the proposed double barrier AlGaN/AlInGaN/GaN MOSHEMT for future applications in high-power and terahertz frequency domains.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-09
Himangshu Kumar, R. Deka
This study looks at how thermal and mass stratification affect the unsteady flow past an infinitely fast-moving vertical plate when the temperature is changing and there is exponential mass diffusion in a porous medium. By applying the Laplace transformation method, we determine the solutions to the equations that govern the system for the case of unitary Prandtl and Schmidt numbers. Graphical representations of the concentration, temperature, and velocity profiles, as well as the Nusselt Number, Sherwood number, and the Skin friction are provided to facilitate discussion of the cause of the different variables. To see the effects of thermal and mass stratification on the fluid flow, we compare the classical solution (Fluid with out stratification) with the primary solution (Fluid with the stratification) by using graph. The combined effects of the two stratification lead to a quicker approach to steady states. The outcomes can be helpful for heat exchange design and other engineering applications.
{"title":"Thermal and Mass Stratification Effects on Unsteady Flow Past an Accelerated Infinite Vertical Plate with Variable Temperature and Exponential Mass Diffusion in Porous Medium","authors":"Himangshu Kumar, R. Deka","doi":"10.26565/2312-4334-2023-4-09","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-09","url":null,"abstract":"This study looks at how thermal and mass stratification affect the unsteady flow past an infinitely fast-moving vertical plate when the temperature is changing and there is exponential mass diffusion in a porous medium. By applying the Laplace transformation method, we determine the solutions to the equations that govern the system for the case of unitary Prandtl and Schmidt numbers. Graphical representations of the concentration, temperature, and velocity profiles, as well as the Nusselt Number, Sherwood number, and the Skin friction are provided to facilitate discussion of the cause of the different variables. To see the effects of thermal and mass stratification on the fluid flow, we compare the classical solution (Fluid with out stratification) with the primary solution (Fluid with the stratification) by using graph. The combined effects of the two stratification lead to a quicker approach to steady states. The outcomes can be helpful for heat exchange design and other engineering applications.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-12
Debozani Borgohain
The mathematical model to inspect the effects of changeable thermo-physical properties such as thermal conduction, slip effects and viscosity on Maxwellian nanofluid is proposed. The thermal conductivity increases rapidly due to presence of nanoparticles such as metals, carbides, oxides etc. in base fluid. The flow occurs from the stagnated point pass a stretched sheet with slipped conditions. The characteristics of the Brownian motion as well as the thermophoresis processes are also taken into consideration. By means of similarity transformations, the ODEs are reduced from the equations influencing the fluid flow. A built-in solver of MATLAB namely bvp4c which is a collocation formula implementing the Lobatto IIIa finite differences numerical method is applied to solve these transformed equations numerically. The graphs of the numerical outcomes representing impacts of variations in different parameters on the fluid movement, transfer of heat along with mass are analyzed. This investigation leads to an important aspect that as the thermal conductivity in the flow is intensified, the temperature of the fluid reduces with high aggregation of the nanoparticles near the sheet’s surface. Also, the rates of heat and mass transferral depletes due to the relaxation of Maxwellian fluid. Furthermore, the effectiveness of the present numerical computations is determined by carrying out comparisons of heat and mass transferred rates against the previous analytical results for several values of thermophoresis and Prandtl parameters. The effectiveness of its outcomes can be applied in nanoscience technology and polymeric industries for their developments.
{"title":"Impacts of Temperature Dependent Thermal Conductivity and Viscosity on Slipped Flow of Maxwell Nanofluid","authors":"Debozani Borgohain","doi":"10.26565/2312-4334-2023-4-12","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-12","url":null,"abstract":"The mathematical model to inspect the effects of changeable thermo-physical properties such as thermal conduction, slip effects and viscosity on Maxwellian nanofluid is proposed. The thermal conductivity increases rapidly due to presence of nanoparticles such as metals, carbides, oxides etc. in base fluid. The flow occurs from the stagnated point pass a stretched sheet with slipped conditions. The characteristics of the Brownian motion as well as the thermophoresis processes are also taken into consideration. By means of similarity transformations, the ODEs are reduced from the equations influencing the fluid flow. A built-in solver of MATLAB namely bvp4c which is a collocation formula implementing the Lobatto IIIa finite differences numerical method is applied to solve these transformed equations numerically. The graphs of the numerical outcomes representing impacts of variations in different parameters on the fluid movement, transfer of heat along with mass are analyzed. This investigation leads to an important aspect that as the thermal conductivity in the flow is intensified, the temperature of the fluid reduces with high aggregation of the nanoparticles near the sheet’s surface. Also, the rates of heat and mass transferral depletes due to the relaxation of Maxwellian fluid. Furthermore, the effectiveness of the present numerical computations is determined by carrying out comparisons of heat and mass transferred rates against the previous analytical results for several values of thermophoresis and Prandtl parameters. The effectiveness of its outcomes can be applied in nanoscience technology and polymeric industries for their developments.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-02DOI: 10.26565/2312-4334-2023-4-01
V. Patil, J. Pawde, R. Mapari, S.K. Waghmare
In this paper, we aim to describe the cosmic late-time acceleration of the Universe in f(R,Lm) gravity framework proposed by Harko (2010) with the help of an equation of state for strange quark matter. To achieve this, we adopt a specific form of f(R,Lm) gravity as f(R,Lm) =R/2}+ Lnm, where n is arbitrary constants. Here we utilize a hybrid scale factor to resolve the modified field equations in the context of f(R,Lm) gravity for an isotropic and homogeneous Friedmann–Lemaître–Robertson–Walker (FLRW) metric in presence of strange quark matter (SQM). Also, we analyze the dynamics of energy density, pressure and the state finder parameters and explained the distinctions between our model and the current dark energy models in the presence of SQM. We observed a transition from an accelerating to a decelerating phase in the Universe, followed by a return to an accelerating phase at late times. Also, we analyzed the state finder diagnostic as well equation of state parameter and found that the model exhibited quintessence-like behavior. The conclusion drawn from our investigation was that the proposed f(R, Lm) cosmological model aligns well with recent observational studies and effectively describes the cosmic acceleration observed during late times.
{"title":"FLRW Cosmology with Hybrid Scale Factor in f(R, Lm) Gravity","authors":"V. Patil, J. Pawde, R. Mapari, S.K. Waghmare","doi":"10.26565/2312-4334-2023-4-01","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-01","url":null,"abstract":"In this paper, we aim to describe the cosmic late-time acceleration of the Universe in f(R,Lm) gravity framework proposed by Harko (2010) with the help of an equation of state for strange quark matter. To achieve this, we adopt a specific form of f(R,Lm) gravity as f(R,Lm) =R/2}+ Lnm, where n is arbitrary constants. Here we utilize a hybrid scale factor to resolve the modified field equations in the context of f(R,Lm) gravity for an isotropic and homogeneous Friedmann–Lemaître–Robertson–Walker (FLRW) metric in presence of strange quark matter (SQM). Also, we analyze the dynamics of energy density, pressure and the state finder parameters and explained the distinctions between our model and the current dark energy models in the presence of SQM. We observed a transition from an accelerating to a decelerating phase in the Universe, followed by a return to an accelerating phase at late times. Also, we analyzed the state finder diagnostic as well equation of state parameter and found that the model exhibited quintessence-like behavior. The conclusion drawn from our investigation was that the proposed f(R, Lm) cosmological model aligns well with recent observational studies and effectively describes the cosmic acceleration observed during late times.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The objective of this study is to investigate, through numerical simulations, the flow and heat transfer characteristics of Al2O3, Cu, TiO2, and SiC water-based nanofluids flowing over micro-cylinder groups arranged in an inline configuration. The simulations were carried out under laminar flow conditions, and the analysis considered seven different low values of the Reynolds number, with a constant volume fraction of 2%. The aim of this investigation was to determine how nanofluids, i.e., suspensions of nanoparticles in water as the base fluid, can affect the pressure drop and heat transfer performance in micro-cylinder groups. To accomplish this, the finite volume method was employed to evaluate the impact of the nanofluids on pressure drop and heat transfer characteristics in the micro-cylinder groups. The study results demonstrate that, for all the nanofluids studied, the pressure drop and friction factor of the micro-cylinder groups increased with increasing Reynolds number. This behavior can be attributed to the interaction between the nanoparticles and the wall, which results in an increase in friction. Furthermore, the Nusselt number was found to increase with increasing Reynolds number. The SiC/Water nanofluid exhibited the highest Nusselt numbers among the four nanofluids tested, indicating that it provides better heat transfer performance than the other nanofluids. These results are consistent with experimental findings, indicating that the numerical simulations were accurate and reliable.
本研究的目的是通过数值模拟研究 Al2O3、Cu、TiO2 和 SiC 水性纳米流体在以内联配置方式排列的微圆柱组上流动时的流动和传热特性。模拟是在层流条件下进行的，分析考虑了七个不同的雷诺数低值，体积分数恒定为 2%。这项研究的目的是确定纳米流体（即纳米颗粒在水基流体中的悬浮液）如何影响微气缸组中的压降和传热性能。为此，研究人员采用有限体积法评估了纳米流体对微气缸组压降和传热特性的影响。研究结果表明，对于所研究的所有纳米流体，微气缸组的压降和摩擦因数随着雷诺数的增加而增大。这种行为可归因于纳米颗粒与壁之间的相互作用，从而导致摩擦力增加。此外，还发现随着雷诺数的增加，努塞尔特数也在增加。在测试的四种纳米流体中，SiC/水纳米流体的努塞尔特数最高，表明它比其他纳米流体具有更好的传热性能。这些结果与实验结果一致，表明数值模拟准确可靠。
{"title":"Analysis of the Heat Transfer Performance of Nanofluids in Micro-Cylinder Groups","authors":"Lina Wafaa Belhadj Senini, Mustpaha Boussoufi, Amina Sabeur","doi":"10.26565/2312-4334-2023-4-11","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-4-11","url":null,"abstract":"The objective of this study is to investigate, through numerical simulations, the flow and heat transfer characteristics of Al2O3, Cu, TiO2, and SiC water-based nanofluids flowing over micro-cylinder groups arranged in an inline configuration. The simulations were carried out under laminar flow conditions, and the analysis considered seven different low values of the Reynolds number, with a constant volume fraction of 2%. The aim of this investigation was to determine how nanofluids, i.e., suspensions of nanoparticles in water as the base fluid, can affect the pressure drop and heat transfer performance in micro-cylinder groups. To accomplish this, the finite volume method was employed to evaluate the impact of the nanofluids on pressure drop and heat transfer characteristics in the micro-cylinder groups. The study results demonstrate that, for all the nanofluids studied, the pressure drop and friction factor of the micro-cylinder groups increased with increasing Reynolds number. This behavior can be attributed to the interaction between the nanoparticles and the wall, which results in an increase in friction. Furthermore, the Nusselt number was found to increase with increasing Reynolds number. The SiC/Water nanofluid exhibited the highest Nusselt numbers among the four nanofluids tested, indicating that it provides better heat transfer performance than the other nanofluids. These results are consistent with experimental findings, indicating that the numerical simulations were accurate and reliable.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139187519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-04DOI: 10.26565/2312-4334-2023-3-17
Ali A. Rakhees, Khalid S. Jassim
Specific systematic studies on the nuclear potential parameter for the heavy-ion reactions, which includes the systems, have been achieved by using large-angle quasi-elastic scattering at deep sub-barrier energies close to the Coulomb barrier height. Single-channel (SC) and coupled-channel calculations have been carried out to elicit the nuclear potential. The chi-square method χ2 has been used to find the best value of the nuclear potential compared to the experimental data. The best values of the nuclear potential were found from the calculations of the coupled channels for an inert projectile and a vibrating target for systems: 9Be+208Pb,10Be+208Pb, 11Be+208Pb, which are equal to 45 MeV,65 MeV,53 MeV, respectively.
{"title":"A Study the Nuclear Potential Using Quasi-Elastic Scattering Calculation for the 9,10,11Be+208Pb Reactions","authors":"Ali A. Rakhees, Khalid S. Jassim","doi":"10.26565/2312-4334-2023-3-17","DOIUrl":"https://doi.org/10.26565/2312-4334-2023-3-17","url":null,"abstract":"Specific systematic studies on the nuclear potential parameter for the heavy-ion reactions, which includes the systems, have been achieved by using large-angle quasi-elastic scattering at deep sub-barrier energies close to the Coulomb barrier height. Single-channel (SC) and coupled-channel calculations have been carried out to elicit the nuclear potential. The chi-square method χ2 has been used to find the best value of the nuclear potential compared to the experimental data. The best values of the nuclear potential were found from the calculations of the coupled channels for an inert projectile and a vibrating target for systems: 9Be+208Pb,10Be+208Pb, 11Be+208Pb, which are equal to 45 MeV,65 MeV,53 MeV, respectively.","PeriodicalId":42569,"journal":{"name":"East European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135498610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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