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Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy
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Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Energy Science and Technology".

Deadline for manuscript submissions: closed (31 December 2019) | Viewed by 50850

Special Issue Editors

Prof. Dr. Cheng-Yu Ku

E-Mail Website
Guest Editor
Department of Harbor and River Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan
Interests: slope stability; numerical methods; groundwater modeling; hydrogeology; geotechnical analysis; geographic information systems
Special Issues, Collections and Topics in MDPI journals
Prof. Dr. Chia-Ming Fan

E-Mail Website
Guest Editor
Department of Harbor and River Engineering & Computation and Simulation Center, National Taiwan Ocean University, Keelung 20224, Taiwan
Interests: fluid mechanics; modeling and simulation; computational fluid dynamics; numerical simulation
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Heat and mass transfer generally covers a wide variety of engineering disciplines concerning theoretical research, fundamental studies, mathematical modeling, numerical simulations, and experimental investigations relating to any kind of current and emerging topics in heat and mass transfer in equipment, systems, processes, materials, and related objects.

This Special Issue welcomes high-quality submissions that, through theory and/or simulation, seek to advance the understanding of “heat and mass transfer: fundamentals and applications in thermal energy”. It focuses on both analytical and experimental research, with an emphasis on contributions which increase the basic understanding of heat and mass transfer processes in porous materials and their application to engineering problems. The scope of the Special Issue includes, but is not limited to the following subjects:

  • Analytical methods for solving problems of heat and mass transfer;
  • Computational techniques in conduction, convection, and radiation teat transfer;
  • Mesh reduction methods (including boundary element methods, method of fundamental solutions, Trefftz method, general finite difference method, and radial basis function method) for modeling the behavior of heat and mass transfer;
  • Inverse problems in heat and mass transfer;
  • Heat and mass transfer in porous materials;
  • Fluid flow and transfer in porous media;
  • Applications of heat and mass transfer in engineering;
  • Other topics on transport phenomena in porous media.

Prof. Dr. Cheng-Yu Ku
Prof. Dr. Chia-Ming Fan
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • heat and mass transfer
  • analytical method
  • computational technique
  • mesh reduction method
  • porous material
  • porous media flow
  • inverse problem

Related Special Issue

Published Papers (16 papers)

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Research

19 pages, 5233 KiB  
Article
An Efficient Meshless Numerical Method for Heat Conduction Studies in Particle Aggregates
by Nikolaos P. Karagiannakis, Nadia Bali, Eugene D. Skouras and Vasilis N. Burganos
Appl. Sci. 2020, 10(3), 739; https://0-doi-org.brum.beds.ac.uk/10.3390/app10030739 - 21 Jan 2020
Cited by 8 | Viewed by 2307
Abstract
A new meshless numerical approach for studying heat conduction in particulate systems was developed that allows the efficient computation of the temperature distribution and the effective thermal conductivity in particle aggregates. The incorporation of the discretization-corrected particle strength exchange operator in meshless local [...] Read more.
A new meshless numerical approach for studying heat conduction in particulate systems was developed that allows the efficient computation of the temperature distribution and the effective thermal conductivity in particle aggregates. The incorporation of the discretization-corrected particle strength exchange operator in meshless local Petrov–Galerkin calculations is suggested here, which was shown to perform better than previously tested trial functions, regarding the speed of convergence and accuracy. Moreover, an automated algorithm for node refinement was developed, which avoids the necessity for user intervention. This was quite important in the study of particle aggregates due to the appearance of multiple points of contact between particles. An alternative approach for interpolation is also presented, that increased the stability of the methods and reduced the computational cost. Test case models, commercial computational fluid dynamics software, and experimental data were used for validation. Heat transport in various aggregate morphologies was also studied using sophisticated aggregation models, in order to quantify the effect of aggregate fractal dimension on the nanofluid conductivity, targeting eventually the optimization of heat transfer applications. A trend of effective conductivity enhancement upon reduction of the fractal dimension of the aggregate was noted. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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21 pages, 600 KiB  
Article
Numerical Study for the Effects of Temperature Dependent Viscosity Flow of Non-Newtonian Fluid with Double Stratification
by Hafiz Abdul Wahab, Hussan Zeb, Saira Bhatti, Muhammad Gulistan, Seifedine Kadry and Yunyoung Nam
Appl. Sci. 2020, 10(2), 708; https://0-doi-org.brum.beds.ac.uk/10.3390/app10020708 - 19 Jan 2020
Cited by 23 | Viewed by 3990
Abstract
The main aim of the current study is to determine the effects of the temperature dependent viscosity and thermal conductivity on magnetohydrodynamics (MHD) flow of a non-Newtonian fluid over a nonlinear stretching sheet. The viscosity of the fluid depends on stratifications. Moreover, Powell–Eyring [...] Read more.
The main aim of the current study is to determine the effects of the temperature dependent viscosity and thermal conductivity on magnetohydrodynamics (MHD) flow of a non-Newtonian fluid over a nonlinear stretching sheet. The viscosity of the fluid depends on stratifications. Moreover, Powell–Eyring fluid is electrically conducted subject to a non-uniform applied magnetic field. Assume a small magnetic reynolds number and boundary layer approximation are applied in the mathematical formulation. Zero nano-particles mass flux condition to the sheet is considered. The governing model is transformed into the system of nonlinear Ordinary Differential Equation (ODE) system by using suitable transformations so-called similarity transformation. In order to calculate the solution of the problem, we use the higher order convergence method, so-called shooting method followed by Runge-Kutta Fehlberg (RK45) method. The impacts of different physical parameters on velocity, temperature and concentration profiles are analyzed and discussed. The parameters of engineering interest, i.e., skin fraction, Nusselt and Sherwood numbers are studied numerically as well. We concluded that the velocity profile decreases by increasing the values of S t , H and M. Also, we have analyzed the variation of temperature and concentration profiles for different physical parameters. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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18 pages, 7757 KiB  
Article
The Implicit Keller Box Scheme for Combined Heat and Mass Transfer of Brinkman-Type Micropolar Nanofluid with Brownian Motion and Thermophoretic Effect Over an Inclined Surface
by Khuram Rafique, Muhammad Imran Anwar, Masnita Misiran, Ilyas Khan and El-Sayed M. Sherif
Appl. Sci. 2020, 10(1), 280; https://0-doi-org.brum.beds.ac.uk/10.3390/app10010280 - 30 Dec 2019
Cited by 19 | Viewed by 2766
Abstract
The main purpose of the present analysis is to report the numerical solution of the thermal radiations and magnetohydrodynamic (MHD) effect on the flow of micropolar nanofluid. Further, the effect of Brownian motion and thermophoresis on the flow field are also elucidated. The [...] Read more.
The main purpose of the present analysis is to report the numerical solution of the thermal radiations and magnetohydrodynamic (MHD) effect on the flow of micropolar nanofluid. Further, the effect of Brownian motion and thermophoresis on the flow field are also elucidated. The combined phenomenon of heat and mass transfer is considered. Compatible similarities are implemented for the conversion of nonlinear ordinary differential equations from nonlinear partial differential equations. The numerical solution of the governing differential equations is obtained via the implicit Keller box technique. This is an efficient scheme based on the finite difference method. Findings demonstrate that the heat and mass exchange reduce with growth of the Brinkman parameter, whereas the wall shear stress enhances with improving the magnitude of the Brinkman factor. The temperature contour enhances when the radiation parameter reaches its peak, which is useful for industrial processes. The heat and mass flow rates decrease against higher magnitudes of inclination. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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11 pages, 1485 KiB  
Article
Boundary Shape Inversion of Two-Dimensional Steady-State Heat Transfer System Based on Finite Volume Method and Decentralized Fuzzy Adaptive PID Control
by Liangliang Yang, Xiaogang Sun and Yuanli Chu
Appl. Sci. 2020, 10(1), 153; https://0-doi-org.brum.beds.ac.uk/10.3390/app10010153 - 23 Dec 2019
Cited by 4 | Viewed by 2327
Abstract
A shape identification scheme was developed to determine the geometric shape of the inaccessible parts of two-dimensional objects using the measured temperatures on their accessible surfaces. The finite volume method was used to calculate the measured point’s temperature in the forward problem. In [...] Read more.
A shape identification scheme was developed to determine the geometric shape of the inaccessible parts of two-dimensional objects using the measured temperatures on their accessible surfaces. The finite volume method was used to calculate the measured point’s temperature in the forward problem. In the inversion problem, the decentralized fuzzy adaptive Proportion Integral Differential (PID) control (DFAC) algorithm was used to compensate for the inversion boundary by using the difference between the measurement temperature and the calculation temperature. More accurate inversion results were obtained by introducing the weighted and synthesized normal distribution. In the inversion problem, the effects of the initial guess, the number of measuring points, and the measurement error were studied. The experiment calculation and analysis showed that the methods adopted in this paper still maintain good validity and accuracy with different initial guesses and decrease the number of measuring points and the existence of measurement errors. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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13 pages, 4522 KiB  
Article
Inversion of Thermal Conductivity in Two-Dimensional Unsteady-State Heat Transfer System Based on Finite Difference Method and Artificial Bee Colony
by Liangliang Yang, Bojun Sun and Xiaogang Sun
Appl. Sci. 2019, 9(22), 4824; https://0-doi-org.brum.beds.ac.uk/10.3390/app9224824 - 11 Nov 2019
Cited by 14 | Viewed by 2575
Abstract
Based on the finite difference method and the artificial bee colony algorithm, the thermal conductivity in the two-dimensional unsteady-state heat transfer system is deduced. An improved artificial bee colony algorithm (IABCA), that artificial bee colony algorithm (ABCA) coupled with calculated deviation feedback, is [...] Read more.
Based on the finite difference method and the artificial bee colony algorithm, the thermal conductivity in the two-dimensional unsteady-state heat transfer system is deduced. An improved artificial bee colony algorithm (IABCA), that artificial bee colony algorithm (ABCA) coupled with calculated deviation feedback, is proposed to overcome the shortcomings of insufficient local exploitation capacity and slow convergence rate in the late stage of the artificial bee colony algorithm (ABCA). For the forward problems, the finite difference method (FDM) is used to calculate the required temperature value of a discrete point; for the inverse problems, the IABCA is applied to minimize the objective function. In the inversion problem, the effects of colony size, number of measuring points, and the existence of measurement errors on the results are studied, and the inversion convergence rate of IABCA and ABCA is compared. The results demonstrate that the methods adopted in this paper had good effectiveness and accuracy even if colony sizes differ and measurement errors exist; and that IABCA has a more efficient convergence rate than ABCA. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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19 pages, 2806 KiB  
Article
New Thermal-Conductivity Constitutive Matrix in Fourier’s Law for Heat Transfer Using the Cell Method
by Pablo Ignacio González-Domínguez, José Miguel Monzón-Verona and Santiago García-Alonso
Appl. Sci. 2019, 9(21), 4521; https://0-doi-org.brum.beds.ac.uk/10.3390/app9214521 - 24 Oct 2019
Cited by 1 | Viewed by 2437
Abstract
In this paper, a new constitutive matrix [ M τ ] for thermal conduction, for tetrahedral meshes, in a steady state thermal regime is developed through a new algebraic methodology, using the Cell Method as a computational method, which is included in the [...] Read more.
In this paper, a new constitutive matrix [ M τ ] for thermal conduction, for tetrahedral meshes, in a steady state thermal regime is developed through a new algebraic methodology, using the Cell Method as a computational method, which is included in the finite formulation. The constitutive matrix defines the behavior of solids when they are under a thermal potential. The results are compared with those obtained for the same problem by means of the constitutive matrix [ M λ ] developed previously, taking in both cases with a 2D axisymmetric model as reference, calculated with the finite element method. The errors obtained with the new matrix [ M τ ] are of the order of 0.0025%, much lower than those obtained with the matrix [ M λ ] . Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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11 pages, 3167 KiB  
Article
Scale-Adaptive Simulation of Unsteady Cavitation Around a Naca66 Hydrofoil
by Víctor Hidalgo, Xavier Escaler, Esteban Valencia, Xiaoxing Peng, José Erazo, Diana Puga and Xianwu Luo
Appl. Sci. 2019, 9(18), 3696; https://0-doi-org.brum.beds.ac.uk/10.3390/app9183696 - 05 Sep 2019
Cited by 20 | Viewed by 3878
Abstract
The present paper focuses on the numerical simulation of unsteady cavitation around a NACA66 hydrofoil to improve the understanding of the cavitation effects on hydraulic machinery. For this aim, the Zwart–Gerber–Belamri cavitation model was updated and uploaded as a library file for OpenFOAM’s [...] Read more.
The present paper focuses on the numerical simulation of unsteady cavitation around a NACA66 hydrofoil to improve the understanding of the cavitation effects on hydraulic machinery. For this aim, the Zwart–Gerber–Belamri cavitation model was updated and uploaded as a library file for OpenFOAM’s solvers using C++ language. Furthermore, the hybrid Reynold average Navier–Stokes (RANS)–large eddy simulation (LES) model k - ω SST scale adaptive simulation (SAS) was implemented as a turbulence model for the present study of scale adaptive simulation. For validation, numerical results were compared with experimental results obtained by Leroux at the Naval Academy Research Institute in France. In order to highlight the benefits in terms of computational consumption and reproduction of the phenomenon the k - ω SST SAS model was compared against implicit large eddy simulation (ILES). Results show that the cavitation evolution including the maximum vapor length, the detachment and the oscillation frequency were reproduced satisfactorily using k - ω SST SAS. Moreover, k - ω SST SAS results predicted a lower total vapor volume on time than ILES, which is related to observed pulses of pressure coefficient, C p , and those match fairly well with the experimental results. To summarize, the k - ω SST SAS model predicts with good accuracy unsteady cavitation behavior around hydrofoils and shows improved versatility over the ILES approach. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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23 pages, 5338 KiB  
Article
Analysis of the Moment Method and the Discrete Velocity Method in Modeling Non-Equilibrium Rarefied Gas Flows: A Comparative Study
by Weiqi Yang, Shuo Tang and Hui Yang
Appl. Sci. 2019, 9(13), 2733; https://0-doi-org.brum.beds.ac.uk/10.3390/app9132733 - 05 Jul 2019
Viewed by 2447
Abstract
In the present study, the performance of the moment method, in terms of accuracy and computational efficiency, was evaluated at both the macro- and microscopic levels. Three different types of non-equilibrium gas flows, including the force-driven Poiseuille flow, lid-driven and thermally induced cavity [...] Read more.
In the present study, the performance of the moment method, in terms of accuracy and computational efficiency, was evaluated at both the macro- and microscopic levels. Three different types of non-equilibrium gas flows, including the force-driven Poiseuille flow, lid-driven and thermally induced cavity flows, were simulated in the slip and transition regimes. Choosing the flow fields obtained from the Boltzmann model equation as the benchmark, the accuracy and validation of Navier–Stokes–Fourier (NSF), regularized 13 (R13) and regularized 26 (R26) equations were explored at the macroscopic level. Meanwhile, we reconstructed the velocity distribution functions (VDFs) using the Hermite polynomials with different-order of molecular velocity moments, and compared them with the Boltzmann solutions at the microscopic level. Moreover, we developed a kinetic criterion to indirectly assess the errors of the reconstructed VDFs. The results have shown that the R13 and R26 moment methods can be faithfully used for non-equilibrium rarefied gas flows in the slip and transition regimes. However, as indicated from the thermally induced case, all of the reconstructed VDFs are still very close to the equilibrium state, and none of them can reproduce the accurate VDF profile when the Knudsen number is above 0.5. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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20 pages, 3807 KiB  
Article
Study of Heat and Mass Transfer in Electroosmotic Flow of Third Order Fluid through Peristaltic Microchannels
by Sadia Waheed, Saima Noreen and Abid Hussanan
Appl. Sci. 2019, 9(10), 2164; https://0-doi-org.brum.beds.ac.uk/10.3390/app9102164 - 27 May 2019
Cited by 42 | Viewed by 3684
Abstract
An analysis is carried out to evaluate the effects of heat and mass transfer in an electro-osmotic flow of third order fluid via peristaltic pumping. Solutions are derived for small wave number and Peclet number. The emerging non-linear mathematical model is solved analytically [...] Read more.
An analysis is carried out to evaluate the effects of heat and mass transfer in an electro-osmotic flow of third order fluid via peristaltic pumping. Solutions are derived for small wave number and Peclet number. The emerging non-linear mathematical model is solved analytically and compared numerically by the built-in scheme of working software. The table is inserted for shear stress distribution and a graph for comparison of solution techniques and accuracy of obtained results. The effects of various parameters of interest on pumping, trapping, temperature, heat transfer coefficient, and concentration distribution have been studied graphically. Electro-osmotic exchange of energy and mass has a role in reservoir engineering, chemical industry, and in micro-fabrication technologies. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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18 pages, 11927 KiB  
Article
Effect of Lateral End Plates on Flow Crossing a Yawed Circular Cylinder
by Hui Liang and Ri-Qiang Duan
Appl. Sci. 2019, 9(8), 1590; https://0-doi-org.brum.beds.ac.uk/10.3390/app9081590 - 17 Apr 2019
Cited by 16 | Viewed by 3315
Abstract
Numerical simulation is carried out to investigate the effect of the boundary condition of two lateral end-plate walls on the flow structure in the wake of a flow crossing a yawed circular cylinder. Two typical boundary conditions, nonslip and periodic, are investigated. It [...] Read more.
Numerical simulation is carried out to investigate the effect of the boundary condition of two lateral end-plate walls on the flow structure in the wake of a flow crossing a yawed circular cylinder. Two typical boundary conditions, nonslip and periodic, are investigated. It is revealed that the boundary condition of the two end-plates has a significant effect on the flow behaviors in the wake. Under the nonslip boundary condition, the vortex structure in the wake exhibits a tapering shape to the tip end. The flow pattern is formed in the wake as the streamlines on the tip side are becoming denser while the streamlines on the base end are becoming sparser. Spectral power analysis of the local lift coefficient shows that the frequency distribution exhibits axial variation. On the base side, the frequency distribution is broadband. On the tip side, there are two peak frequencies: the larger one corresponds to the value predicted by the independence principle, and the smaller one is generated by the secondary axial flow separation from the rear cylinder wall. Under the periodic condition, the numerical results show that organized Strouhal vortex is shed in the wake in the same way as to the flow orthogonally passing a cylinder and the independence principle is still applicable. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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14 pages, 4128 KiB  
Article
The Influence of Chemical Component Distribution on the Radiometric Properties of Particle Aggregates
by Yizhan Chai, Zhen Yang and Yuanyuan Duan
Appl. Sci. 2019, 9(7), 1501; https://0-doi-org.brum.beds.ac.uk/10.3390/app9071501 - 11 Apr 2019
Cited by 1 | Viewed by 2643
Abstract
The radiometric properties, including the extinction efficiency, absorption efficiency, scattering efficiency, and asymmetric parameter values of particle aggregates consisting of multiple chemical components are critical in industry and nature. This article aims to analyze the influence of chemical component distribution on these radiometric [...] Read more.
The radiometric properties, including the extinction efficiency, absorption efficiency, scattering efficiency, and asymmetric parameter values of particle aggregates consisting of multiple chemical components are critical in industry and nature. This article aims to analyze the influence of chemical component distribution on these radiometric properties. The particle aggregates are generated by a diffusion-limited aggregate method by which spherical particles are stuck together randomly. The particle aggregates have two components with a major component of a fixed refractive index and a minor component of a changed refractive index. The radiometric properties are calculated using a multi-sphere T-matrix (MSTM) method for particle aggregates with different particle radii and with refractive indices, distributions of components, and volume fractions of the minor component. The results show that the chemical component distribution influences the radiometric properties of the particle aggregate. Evenly spreading the strong absorptive minor component into each particle, compared to concentrating it in a few particles, can raise the absorption efficiency, reduce the scattering efficiency, and ultimately reduce the extinction efficiency of the aggregate. For aggregates with major and minor components in different particles, a similar effect is shown when spreading the minor component particles evenly in the aggregate relative to gathering them in one part of the aggregate. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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15 pages, 4399 KiB  
Article
Two-Dimensional Modeling of Pressure Swing Adsorption (PSA) Oxygen Generation with Radial-Flow Adsorber
by Xiong Yang, Haoyu Wang, Jiangwei Chen, Ziyi Li, Yingshu Liu, Chuanzhao Zhang and Yi Xing
Appl. Sci. 2019, 9(6), 1153; https://0-doi-org.brum.beds.ac.uk/10.3390/app9061153 - 19 Mar 2019
Cited by 12 | Viewed by 5204
Abstract
Radial flow is an important type of flow direction for large-scale pressure swing adsorption (PSA) oxygen generation systems. In this study, a numerical simulation of a PSA oxygen generation process based on radial-flow adsorbers was performed with two-dimensional CFD modeling. The gas distribution, [...] Read more.
Radial flow is an important type of flow direction for large-scale pressure swing adsorption (PSA) oxygen generation systems. In this study, a numerical simulation of a PSA oxygen generation process based on radial-flow adsorbers was performed with two-dimensional CFD modeling. The gas distribution, the maldistribution factor and the pressure difference were comparatively investigated at each flow type of the radial-flow adsorber. Considering the gas adsorption performance, the results indicated that the centripetal π-flow radial adsorber has the best flow characteristics for the PSA process. The oxygen purity distribution within the adsorption bed was studied to compare centripetal and centrifugal π-flows, and the former was shown to perform better on oxygen enrichment and adsorbent desorption. The steady state was achieved after eight cycles for the centripetal-π adsorber and each of the four steps of the PSA process was explored in detail to show the advantageous properties for oxygen generation in terms of adsorption and desorption. The relationships between the product flow rate and the oxygen purity and recovery were further investigated. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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20 pages, 3588 KiB  
Article
Experimental and Theoretical Study on the Heat Transfer Coefficients of Building External Surfaces in the Tropical Island Region
by Yaping Cui, Jingchao Xie, Jiaping Liu and Peng Xue
Appl. Sci. 2019, 9(6), 1063; https://0-doi-org.brum.beds.ac.uk/10.3390/app9061063 - 13 Mar 2019
Cited by 7 | Viewed by 2879
Abstract
China is actively promoting ocean territory construction, and how to design low-energy buildings to fit the unique climate of tropical island regions has received much attention. The heat transfer coefficient of a building external surface plays a vital role in calculating air-conditioning load [...] Read more.
China is actively promoting ocean territory construction, and how to design low-energy buildings to fit the unique climate of tropical island regions has received much attention. The heat transfer coefficient of a building external surface plays a vital role in calculating air-conditioning load accurately. To obtain reasonable heat transfer coefficients in the tropical island region, this study introduced a naphthalene sublimation experiment to conduct full-scale measurements on convective heat transfer coefficients (CHTCs) in the tropical island region, and proposed a simplified calculation model of evaporative heat transfer coefficients (EHTCs). Results indicated that the function expression between CHTC and wind speed was CHTC = 5.56 + 4.48u (R2 = 0.94), and it was validated to be reliable. Furthermore, compared with CHTCs and radiation heat transfer coefficients (RHTCs), the EHTC had a wider changing range, owing to rainfall effects. Moreover, whether evaporation was considered or not, the difference of total heat transfer coefficients (THTCs) on building external surfaces was 5.2 W/(m2·K) for the whole year, so evaporation cannot be ignored directly. Additionally, THTCs with consideration of evaporation in winter and summer were 33.4 W/(m2·K) and 38.9 W/(m2·K) severally, which are much larger than the recommended values in the Chinese standard. This study would make up for the lack of surface heat transfer coefficients in energy conservation design of tropical island buildings. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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13 pages, 6604 KiB  
Article
Cavitation Evolution around a NACA0015 Hydrofoil with Different Cavitation Models Based on Level Set Method
by An Yu, Qinghong Tang and Daqing Zhou
Appl. Sci. 2019, 9(4), 758; https://0-doi-org.brum.beds.ac.uk/10.3390/app9040758 - 21 Feb 2019
Cited by 16 | Viewed by 3053
Abstract
Cavitation is a complex multiphase flow phenomenon that is usually involved in marine propulsion systems, and can be simulated with a couple of methods. In this study, three widespread cavitation models were compared using experimental data and a new modified simulation method. The [...] Read more.
Cavitation is a complex multiphase flow phenomenon that is usually involved in marine propulsion systems, and can be simulated with a couple of methods. In this study, three widespread cavitation models were compared using experimental data and a new modified simulation method. The accuracy of the three cavitation models was evaluated regarding their steady and unsteady characteristics, such as the flow field, re-entrant jet, vortex-shedding, and so on. Based on the experimental data and numerical results, the applicability of different cavitation models in different conditions was obtained. The Kunz model can accurately capture both the adverse pressure gradient and the action of the re-entrant jet in sheet cavitation, while the full cavitation model (FCM) has an accurate prediction for the flow field structure and the shedding characteristic of cloud cavitation. Through comparing the results, the optimal selection of cavitation models for further study at different conditions was obtained. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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13 pages, 3737 KiB  
Article
Mass Maldistribution Research of Different Internal Flowing Channels in the Cooling Plate Applied to Electric Vehicle Batteries
by Huikun Cai, Chen Xu, Yidai Liao, Lijun Su and Zeju Weng
Appl. Sci. 2019, 9(4), 636; https://0-doi-org.brum.beds.ac.uk/10.3390/app9040636 - 14 Feb 2019
Cited by 16 | Viewed by 3480
Abstract
As temperature variations will cause electrochemical reactions to proceed at different rates in different regions of the cell, which thereby leads to incomplete energy utilization and inefficient management of battery life, temperature uniformity is becoming a new challenge in thermal management systems of [...] Read more.
As temperature variations will cause electrochemical reactions to proceed at different rates in different regions of the cell, which thereby leads to incomplete energy utilization and inefficient management of battery life, temperature uniformity is becoming a new challenge in thermal management systems of electric vehicle batteries. With the wide application of liquid cooling strategies, temperature uniformity is significantly affected by coolant mass maldistribution, which is significantly affected by the flowing channel configuration in the cooling plate. However, there are few papers on this influence presently. Therefore, this paper presents numerical research on cooling plates with different internal flowing channels. A comparison of the effects among three channel configurations (cavity, parallel, and serpentine) on coolant flowing characteristics is carried out by analyzing their mass maldistribution coefficients and pressure drops. Then, a serpentine channel is selected for further optimization by an orthogonal experiment and range analysis method due to its better comprehensive performance. The study aims to reveal design principles on how channel configuration acts on mass maldistribution, and to demonstrate that significant performance gains can be realized with optimization techniques that can be utilized in battery cooling plates. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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13 pages, 2987 KiB  
Article
An Investigation on the Forced Convection of Al2O3-water Nanofluid Laminar Flow in a Microchannel Under Interval Uncertainties
by Zhaoli Zheng, Qi Jing, Yonghui Xie and Di Zhang
Appl. Sci. 2019, 9(3), 432; https://0-doi-org.brum.beds.ac.uk/10.3390/app9030432 - 28 Jan 2019
Cited by 7 | Viewed by 2139
Abstract
Nanofluids are regarded as an effective cooling medium with tremendous potential in heat transfer enhancement. In reality, nanofluids in microchannels are at the mercy of uncertainties unavoidably due to manufacturing error, dispersion of physical properties, and inconstant operating conditions. To obtain a deeper [...] Read more.
Nanofluids are regarded as an effective cooling medium with tremendous potential in heat transfer enhancement. In reality, nanofluids in microchannels are at the mercy of uncertainties unavoidably due to manufacturing error, dispersion of physical properties, and inconstant operating conditions. To obtain a deeper understanding of forced convection of nanofluids in microchannels, uncertainties are suggested to be considered. This paper studies numerically the uncertain forced convection of Al2O3-water nanofluid laminar flow in a grooved microchannel. Uncertainties in material properties and geometrical parameter are considered. The uncertainties are represented by interval variables. By employing Chebyshev polynomial approximation, interval method (IM) is presented to estimate the uncertain thermal performance and flow behavior of the forced convection problem. The validation of the accuracy and effectiveness of IM are demonstrated by a comparison with the scanning method (SM). The variation of temperature, velocity, and Nusselt number are obtained under different interval uncertainties. The results show that the uncertainties have remarkable influences on the simulated thermal performance and flow behavior. Full article
(This article belongs to the Special Issue Heat and Mass Transfer: Fundamentals and Applications in Thermal Energy)
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