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A New Idea of Fractal-Fractional Derivative with Power Law Kernel for Free convection heat transfer in a Channel Flow between Two Static Upright Parallel Plates

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Computers, Materials & Continua 2020年第11期65卷 1237-1251页

作者： Dolat Khan Gohar Ali Arshad Khan Ilyas Khan Yu-Ming Chu Kottakkaran Sooppy Nisar Department of Mathematics City University of Science and Information TechnologyPeshawar25000Pakistan Institute of Computer Sciences and Information Technology The University of AgriculturePeshawarPakistan Faculty of Mathematics and Statistics Ton Duc Thang UniversityHo Chi Minh72915Vietnam Department of Mathematics Huzhou UniversityHuzhou313000China Hunan Provincial Key Laboratory of Mathematical Modeling and Analysis in Engineering Changsha University of Science&TechnologyChangsha410114China Department of Mathematics College of Arts and SciencesPrince Sattam bin Abdulaziz UniversityWadi Aldawaser11991Saudi Arabia

Nowadays some new ideas of fractional derivatives have been used successfully in the present research community to study different types of mathematical *** them,the significant models of fluids and heat or mass transfer are on *** recently a new idea of fractal-fractional derivative is introduced;however,it is not used for heat transfer in channel *** this article,we have studied this new idea of fractal fractional operators with power-law kernel for heat transfer in a fluid flow *** exactly,we have considered the free convection heat transfer for a Newtonian *** flow is bounded between two parallel static *** of the plates is heated *** proposed problem is modeled with a fractal fractional derivative operator with a power-law kernel and solved via the Laplace transform method to find out the exact *** results are graphically analyzed via MathCad-15 software to study the behavior of fractal parameters and fractional *** the influence of temperature and velocity profile,it is observed that the fractional parameter raised the velocity and temperature as compared to the fractal ***,a combined approach of fractal fractional explains the memory of the function better than fractional only.

关键词： Fractal-fractional derivative power law kernel convection heat transfer upright parallel plates

Characteristics of radiation and convection heat transfer in indirect near-infrared-ray heating chamber

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Journal of Central South University 2011年第3期18卷 731-738页

作者： CHOI Hoon-ki YOO Geun-jong KIM Churl-hwan School of Mechatronics Changwon National University

Numerical study was performed to evaluate the characteristics of combined heat transfer of radiation, conduction and convection in indirect near infrared ray （N/R） heating chamber. The effects of important design parameters such as the shape of heat absorbing cylinder and heat releasing fin on the pressure drop and heat transfer coefficient were analyzed with different Reynolds numbers. The Reynolds numbers were varied from 103 to 3x106, which was defined based on the hydraulic diameter of the heat absorbing cylinder. Analyses were performed to obtain the inner and outer flow and the temperature distributions in the heat absorbing cylinder and the rates of radiation heat transfer and convection heat transfer. As the Reynolds number increases, the convection heat transfer rate is increased while the radiation heat transfer rate is decreased. The average convection heat transfer rate follows a power rule of the Reynolds number. Addition of three-dimensional heat releasing fin to the outside of the heat absorbing cylinder enhances the convection heat transfer.

关键词： near infrared ray indirect near infrared ray heater absorbing cylinder heat releasing fin radiation heat transfer convection heat transfer Reynolds number

A Coupled Discrete Unified Gas-Kinetic Scheme for convection heat transfer in Porous Media

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Communications in Computational Physics 2021年第1期29卷 265-291页

作者： Peiyao Liu Peng Wang Long Jv Zhaoli Guo State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan430074P.R.China

In this paper,the discrete unified gas-kinetic scheme(DUGKS)is extended to the convection heat transfer in porous media at representative elementary volume(REV)scale,where the changes of velocity and temperature fields are described by two kinetic *** effects from the porous medium are incorporated into the method by including the porosity into the equilibrium distribution function,and adding a resistance force in the kinetic equation for the velocity *** proposed method is systematically validated by several canonical cases,including the mixed convection in porous channel,the natural convection in porous cavity,and the natural convection in a cavity partially filled with porous *** numerical results are in good agreement with the benchmark solutions and the available experimental *** is also shown that the coupled DUGKS yields a second-order accuracy in both temporal and spatial spaces.

关键词： Coupled discrete unified gas-kinetic scheme generalized Navier-Stokes equations porous media convection heat transfer

convection heat transfer from heated Thin Cylinders Inside a Ventilated Enclosure

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Semiconductor Science and Information Devices 2022年第2期4卷 10-16页

作者： Ali Riaz Adnan Ibrahim Muhammad Sohail Bashir Muhammad Abdullah Ajmal Shah Abdul Quddus Department of Mechanical Engineering Pakistan Institute of Engineering and Applied SciencesIslamabad45650Pakistan School of Engineering Science University of Science and Technology of ChinaHefeiAnhui230027China Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Soft Matter ChemistryDepartment of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefeiAnhui230026China

Experimental study was conducted to determine the effect of velocity of axial fan,outlet vent height,position,area,and aspect ratio(h/w)of ventilated enclosure on convection heat *** wooden ventilated enclosure having top and front transparent wall was made up of Perspex for visualization,and internal physical dimensions of box were 200 mm×200 mm×400 *** vent was at bottom while outlet vents were at the side and top *** heated cylindrical heat source having 6.1 slenderness ratio was fabricated and hanged at the centre of the *** calculate heat transfer rates,thermocouples were attached to the inner surface of heat source with silica *** source was operated at constant heat flux in order to quantify the effect of velocity of air on heat *** was observed that average Nusselt number was increased from 68 to 216 by changing velocity from 0 to 3.34 m/s at constant modified Grashof number i.e.5.67E+*** variation in outlet height at the front wall did not affect heat transfer in forced convection ***,Nusselt number decreased to 5%by changing the outlet position from top to the front wall or by 50%reduction in outlet area during forced *** rise in temperature of enclosure increased from 8.19 K to 9.40 K by increasing aspect ratio of enclosure from 1.5 to 2 by operating heat source at constant heat flux i.e.541.20 w/m^(2).

关键词： Experimentation Ventilated enclosures convection heat transfer Dimensionless data

Numerical and Experimental Study on heat transfer Characteristics of Single Vibrating Blade in a Channel Flow

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Journal of Thermal Science 2023年第3期32卷 982-992页

作者： HU Jinqi MIN Chunhua YANG Xuguang WANG Kun XIE Liyao School of Energy and Environmental Engineering Hebei University of TechnologyTianjin 300401China Hebei Key Laboratory of Thermal Science and Energy Clean Utilization Hebei University of TechnologyTianjin 300401China

The heat transfer characteristics of the vibrating blades of different shapes were numerically modeled in the present work.A single blade was arranged in a channel with vertical or horizontal *** the static environment and the channel flow were *** types of blades,rectangular,trapezoidal,serrated,and folding,were comparably *** results showed that the vibrating blade could effectively enhance the convection heat transfer of the heated surface with a smaller increase of pressure *** the static environment,the heat transfer performance of the vertical alignment of the blade is better than the horizontal *** channel flow,the opposite conclusion is *** the inlet velocity of channel flow v_(inlet)=2 m/s and v_(inlet)=6m/s,the maximum improvement of the local convection heat transfer coefficient is about 98%and 12%,*** corresponding pressure drops were reduced and increased by 9.5%and 8.8%,*** vibrating blade can effectively improve the convection heat transfer at lower inlet *** the same working conditions,the pressure drop difference between the four shapes of fan blades is less than 1%,and the folding blade has the best local heat dissipation performance.

关键词： convection heat transfer vibrating blade alignment of the blade shape of the blade

Efficiency Analysis of an Arrayed Liquid Piston Isothermal Air Compression System for Compressed Air Energy Storage

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Journal of Thermal Science 2023年第1期32卷 17-29页

作者： HU Shiwei XU Weiqing JIA Guanwei CAI Maolin LI Jidong LU Yueke REN Teng School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Pneumatic and Thermodynamic Energy Storage and Supply Beijing Key Laboratory Beijing 100191China School of Physics&Electronics Henan UniversityKaifeng 475004China School of Mechanical Engineering Shenyang University of TechnologyShenyang 110870China

Compressed air energy storage(CAES)is an important technology in the development of renewable *** main advantages of CAES are its high energy capacity and environmental *** of the main challenges is its low energy density,meaning a natural cavern is required for air ***-pressure air compression can effectively solve the problem.A liquid piston gas compressor facilitates high-pressure compression,and efficient convective heat transfer can significantly reduce the compression energy consumption during air *** this paper,a near isothermal compression method is proposed to increase the surface area and heat exchange by using multiple tube bundles in parallel in the compression chamber in order to obtain high-pressure air using liquid-driven *** compression with a compression ratio of 6.25:1 is achieved by reducing the tube diameter and increasing the parallel tube number while keeping the compression chamber cross-sectional area constant in order to obtain a high-pressure air of 5 *** performances of this system are analyzed when different numbers of tubes are applied.A system compression efficiency of 93.0%and an expansion efficiency of 92.9%can be achieved when 1000 tubes are applied at a 1 minute period.A new approach is provided in this study to achieve high efficiency and high pressure compressed air energy storage.

关键词： liquid piston gas compressor compressed air energy storage convection heat transfer high-pressure air

Fluid Flow and Infrared Image Analyses on Endwall Fitted with Short Rectangular Plate Fin

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Journal of Thermal Science 2006年第2期15卷 145-151页

作者： Kenyu OYAKAWA Islam Md. DIDARUL Minoru YAGA Dept. of Mechanical Systems Engineering University of the Ryukyus Okinawa Japan. Faculty of Engineering University of the Ryukyus Okinawa Japan.

An experimental investigation is carded out to study fluid flow and heat transfer characteristics on the endwall fitted with arrays （ 7 × 7 ） of short rectangular plate fins of different pattern （co-angular and zigzag） for different pitch ratio. Experiments were conducted in a rectangular duct of 50 mm height for an air flow of Reynolds number ranged from 18750 to 62500 based on the equivalent diameter and air velocity of the duct. Infrared image analysis technique was employed to make clear the characteristics of local heat transfer coefficients on fin base, endwall and overall surface. Flow pattern around the short rectangular plates were visualized by inducing fluorescent dye in a water channel and longitudinal vortices were observed. Increasing the distance between plates in flow direction causes heat transfer enhancement for co-angular pattern, while decreasing the distance causes heat transfer enhancement for zigzag pattern. Zigzag pattern with pitch ratio 2 is found to be more effective in heat transfer enhancement than any other cases investigated.

关键词： infrared image rectangular plate convection heat transfer flow visualization

Reaction characteristics of magnesium production under argon flow by silicothermic reduction and numerical simulation of argon entrainment process

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Journal of Magnesium and Alloys 2023年第10期11卷 3710-3723页

作者： Shiming Zhang Chao Zhang Gengpeng Mai Jianxun Song Yusi Che Jilin He School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China Henan Province Industrial Technology Research Institute of Resources and Materials Zhengzhou UniversityZhengzhou 450001China School of Thermal Engineering Shandong Jianzhu UniversityJinan 250101China

In this study, the reaction characteristics of reduction of calcined dolomite with ferrosilicon under argon flow to produce magnesium were studied by conducting experiments Pidgeon pellets were used to study the effect of reduced temperature, argon flow, and reduced time on the conversion of calcined dolomite reduction by ferrosilicon. The results show that the conversion significantly increases with the increase in the reduction temperature and reduction time. The conversion first increases and then decreases with the increase in argon flow. The highest conversion was obtained when the argon flow rate was 3 L·min^(-1), and a nearly spherical shape, nanoscale magnesium powder was obtained. Then the characters of the circulating argon entrainment process were numerically studied by ANSYS Fluent 17. A physical model of multilayer pellet arrangement was established, and a numerical calculation model of chemical reaction, radiation, heat conduction, and convection heat transfer was constructed. This confirms that high-temperature argon can effectively strengthen the heat exchange between pellets, improve the heat transfer efficiency, and facilitate the pellets to react quickly. When the conversion is 80%, the production efficiency increased by about 28.6%. In addition, the magnesium production efficiency showed an increase tendency with the increase of the argon inlet flow rate.

关键词： Silicothermic reduction of magnesium Enhanced heat transfer convection heat transfer Numerical simulation Argon flow

An Investigation into the Influence of the Airflow Path on the Convective heat transfer for an Eddy Current Retarder Turntable

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Fluid Dynamics & Materials Processing 2020年第5期16卷 961-977页

作者： Yunfei Liao Jin Liu Chongqing Industry Polytechnic College Chongqing401120China Shenzhen Terca Technology Co. Ltd.Shenzhen518110China

In order to improve the convective heat transfer relating to an eddy current retarder,the finite element model has been used to assess the performances of different possible *** particular,assuming the steady running state of retarder as the working condition,flow and temperature fields have been obtained for the *** influence of airflow path on heat dissipation has been analysed,and the influence of the temperature field distribution on the performance of retarder has been discussed *** results show that when the steady running state of the turntable is considered,the maximum temperature is lower,the level of turbulence flow is mitigated,and the temperature distribution becomes more *** factors contribute to improve the heat dissipation ability of the retarder.

关键词： Eddy current retarder turntable flow field convection heat transfer