Analysis of Radiative Magneto-Nanofluid over an Accelerated Plate in a Rotating Medium with Hall Effects

Present research work has been undertaken to analyze the effects of Hall current on natural convective flow of radiative, incompressible, viscous and electrically conducting magneto-nanofluid over a uniformly accelerated moving vertical ramped temperature plate in a rotating medium. Three types of water based nanofluids containing the nanoparticles of alumina, copper and titanium oxide have been accounted. The mathematical model of the problem has been presented using the nanoparticle volume fraction model. The Laplace transform technique has been employed to solve the mathematical model. The closed-form expressions of nanofluid velocity, temperature, shear stress and rate of heat transfer at the plate have been obtained for both the conditions of ramped temperature and isothermal plates. The effects of various physical parameters on the nanofluid velocity due to primary and secondary flows and temperature have been exemplified using various graphs whereas, the numerical values of shear stress and rate of heat transfer at the plate have been reported in tabular form for different values of physical parameters of interest. Moreover, the numerical results have been compared for the natural convective flow near ramped temperature plate with the corresponding flow near isothermal plate. It has been noted that both the nanofluid velocity and temperature are higher in magnitude in the case of isothermal plate than that of ramped temperature plate. The results of present research work have been validated with the earlier published work.

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Numerical Modelling of Heat Transfer in Fine Dispersive Slurry Flow

Energies ◽

10.3390/en14164909 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4909

Author(s):

Artur Bartosik

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Shear Stress ◽

Nusselt Number ◽

Numerical Modelling ◽

Liquid Flow ◽

Slurry Flow ◽

Carrier Liquid ◽

New Correlation ◽

The Mathematical Model

Slurry flows commonly appear in the transport of minerals from a mine to the processing site or from the deep ocean to the surface level. The process of heat transfer in solid–liquid flow is especially important for the long pipeline distance. The paper is focused on the numerical modelling and simulation of heat transfer in a fine dispersive slurry, which exhibits yield stress and damping of turbulence. The Bingham rheological model and the apparent viscosity concept were applied. The physical model was formulated and then the mathematical model, which constitutes conservative equations based on the time average approach for mass, momentum, and internal energy. The slurry flow in a pipeline is turbulent and fully developed hydrodynamically and thermally. The closure problem was solved by taking into account the Boussinesque hypothesis and a suitable turbulence model, which includes the influence of the yield shear stress on the wall damping function. The objective of the paper is to develop a new correlation of the Nusselt number for turbulent flow of fine dispersive slurry that exhibits yield stress and damping of turbulence. Simulations were performed for turbulent slurry flow, for solid volume concentrations 10%, 20%, 30%, and for water. The mathematical model for heat transfer of the carrier liquid flow has been validated. The study confirmed that the slurry velocity profiles are substantially different from those of the carrier liquid and have a significant effect on the heat transfer process. The highest rate of decrease in the Nusselt number is for low solid concentrations, while for C > 10% the decrease in the Nusselt number is gradual. A new correlation for the Nusselt number is proposed, which includes the Reynolds and Prandtl numbers, the dimensionless yield shear stress, and solid concentration. The new Nusselt number is in good agreement with the numerical predictions and the highest relative error was obtained for C = 10% and Nu = 44.3 and is equal to −12%. Results of the simulations are discussed. Conclusions and recommendations for further research are formulated.

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Modeling and Analysis of Energy/Exergy for Absorber Pipes of Linear Parabolic Concentrating Systems

International Journal of Photoenergy ◽

10.1155/2021/7929756 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Reza Alayi ◽

Mahdi Mohkam ◽

Hossein Monfared ◽

Alibek Issakhov ◽

Nima Khalilpoor

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Numerical Solutions ◽

Physical Parameters ◽

Fluid Temperature ◽

Solar Collectors ◽

Matlab Software ◽

Modeling And Analysis ◽

Parabolic Collector ◽

The Mathematical Model

In this paper, the physical parameters of the absorber pipe of a linear parabolic collector have been investigated. The types of solar collectors, specifically the linear parabolic collector, have been comprehensively studied. Then, the mathematical model of heat transfer in the absorber pipe of the collector has been presented based on valid references. Numerical solutions of the equations related to the absorber pipe were performed by MATLAB software, and the effects of the physical parameters of the absorber pipe on its efficiency were investigated. The results show that increasing the length of the absorber pipe causes a nonlinear decrease in the efficiency of the absorber pipe. One of the important results is the increase in fluid temperature due to the increase in the diameter of the adsorbent tube, which increases the diameter of the fluid temperature by 60 K, in which the parameter increases the efficiency by 0.38%.

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Systems Actuated by Shape Memory Alloys: Identification and Modeling

SYSTEM THEORY, CONTROL AND COMPUTING JOURNAL ◽

10.52846/stccj.2021.1.2.20 ◽

2021 ◽

Vol 1 (2) ◽

pp. 12-20

Author(s):

Najmeh Keshtkar ◽

Johannes Mersch ◽

Konrad Katzer ◽

Felix Lohse ◽

Lars Natkowski ◽

...

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Constitutive Model ◽

Shape Memory Alloys ◽

Numerical Simulations ◽

Shape Memory ◽

Transfer Equation ◽

Mechanical Parameters ◽

Heat Transfer Equation ◽

The Mathematical Model

This paper presents the identification of thermal and mechanical parameters of shape memory alloys by using the heat transfer equation and a constitutive model. The identified parameters are then used to describe the mathematical model of a fiber-elastomer composite embedded with shape memory alloys. To verify the validity of the obtained equations, numerical simulations of the SMA temperature and composite bending are carried out and compared with the experimental results.

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Motion Simulation for Triangular-Shaped Autonomous Underwater Vehicle (TAUV) with Controllable Rudder

Journal of Physics Conference Series ◽

10.1088/1742-6596/2107/1/012046 ◽

2021 ◽

Vol 2107 (1) ◽

pp. 012046

Author(s):

I Y Amran ◽

K Isa

Keyword(s):

Mathematical Model ◽

Autonomous Underwater Vehicle ◽

Research Work ◽

Underwater Vehicle ◽

Open Loop ◽

Vehicle Speed ◽

Motion Simulation ◽

Loop Control ◽

Angular Velocities ◽

The Mathematical Model

Abstract The dynamic model and motion simulation for a Triangular-Shaped Autonomous Underwater Vehicle (TAUV) with independently controlled rudders are described in this paper. The TAUV is designed for biofouling cleaning in aquaculture cage fishnet. It is buoyant underwater and moves by controlling two thrusters. Hence, in this research work, the authors designed a TAUV that is propelled by two thrusters and maneuvered by using an independently controllable rudder. This paper discussed the development of a mathematical model for the TAUV and its dynamic characteristics. The mathematical model was simulated by using Matlab and Simulink to analyze the TAUV’s motion based on open-loop control of different rudder angles. The position, linear and angular velocities, angle of attack, and underwater vehicle speed are all demonstrated in the findings.

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Development of condenser mathematical model for research and development of ways to improve its efficiency

Istrazivanja i projektovanja za privredu ◽

10.5937/jaes0-27517 ◽

2020 ◽

Vol 18 (4) ◽

pp. 578-585

Author(s):

Madina Shavdinova ◽

Konstantin Aronson ◽

Nina Borissova

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Water Temperature ◽

Steam Turbine ◽

Cooling Water ◽

Laboratory Research ◽

Thermal Engineering ◽

Linear Regression Method ◽

Cooling Water Temperature ◽

The Mathematical Model

The condensing unit is one of the most important elements of the steam turbine of a combined heat and power plant. Defects in elements of the condensing unit lead to disturbances in the steam turbine operation, its failures and breakdowns, as well as efficiency losses of the plant. Therefore, the operating personnel need to know the cause of the malfunction and to correct it immediately. There are no diagnostic models of condensers in the Republic of Kazakhstan at the moment. In this regard, a mathematical model of a condenser based on the methodology of Kaluga Turbine Plant (KTP) has been developed. The mathematical model makes it possible to change the input parameters, plot dependency diagrams, and calculate the plant efficiency indicators. The mathematical model of the condenser can be used to research ways for the improvement of the condensing unit efficiency, for diagnostic purposes of the equipment condition, for the energy audit conduction of the plant, and in the training when performing virtual laboratory research. Using static data processing by linear regression method we obtain that the KTP methodology of condenser calculation is fair at cooling water temperature from 20 °C to 24 °C, but at cooling water temperature from 20 °C to 28 °C, the methodology of JSC "All-Russia Thermal Engineering Institute" (JSC "VTI") is used. One of the ways to increase the condenser efficiency has been proposed. It is the heat transfer augmentation with riffling annular grooves on tubes. This method increases the heat transfer coefficient by 2%, reduces the water subcooling of the heating steam by 0.9 °C, and decreases the cooling area by 2%.

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Parametric Study of Temperature Field During the Cooling Stage for Extrusion Blow Molded Part

Heat Transfer, Part B ◽

10.1115/imece2005-80373 ◽

2005 ◽

Author(s):

Zhan-Song Yin ◽

Hon-Xiong Huang

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Internal Heat ◽

Mold Material ◽

Orthogonal Experimental Design ◽

Ann Model ◽

Molded Part ◽

Artificial Neural Network Ann ◽

The Mathematical Model ◽

Part Thickness

A mathematical model of the transient heat transfer during the cooling and solidification of extrusion blow molded part was developed. The temperature profiles were obtained by using finite element (FE) code POLYFLOW to solve the mathematical model. The influences of blow mold material, internal heat transfer coefficient, part thickness, and initial parison temperature on cooling were analyzed. An orthogonal experimental design was applied to determine the significance of four process parameters on the time for opening the mold. The calculated results were estimated by analysis of variance (ANVOA). An artificial neural network (ANN) model based on the numerical simulation data was developed to build for predicting the temperature distribution across thickness. The results showed that ANN approach was an effective method for analyzing the cooling of blow molded part.

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Heat Convection from a Horizontal Cylinder Rotating in a Quiescent Fluid

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-1986-0017 ◽

1986 ◽

Vol 10 (3) ◽

pp. 141-152

Author(s):

H.M. Badr ◽

S.M. Ahmed

Keyword(s):

Heat Transfer ◽

Experimental Data ◽

Mathematical Model ◽

Horizontal Cylinder ◽

Heat Transfer Process ◽

Two Dimensional ◽

Two Dimensional Flow ◽

Boussinesq Fluid ◽

The Mathematical Model ◽

Quiescent Fluid

The aim of this work is a theoretical investigation to the problem of heat transfer from an isothermal horizontal cylinder rotating in a quiescent fluid. The study is based on the solution of the conservation equations of mass, momentum and energy for two-dimensional flow of a Boussinesq fluid. The effects of the parameters which influence the heat transfer process namely the Reynolds number and Grashof number are considered while the Prandtl number is held constant. Streamline and isotherm patterns are obtained from the mathematical model and the results are compared with previous experimental data. A satisfactory agreement was found.

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RADIATION EFFECTS ON AN UNSTEADY NATURAL CONVECTIVE FLOW OF A NANOFLUID PAST AN INFINITE VERTICAL PLATE

NANO ◽

10.1142/s179329201350001x ◽

2013 ◽

Vol 08 (01) ◽

pp. 1350001 ◽

Cited By ~ 22

Author(s):

P. LOGANATHAN ◽

P. NIRMAL CHAND ◽

P. GANESAN

Keyword(s):

Heat Transfer ◽

Skin Friction ◽

Convective Flow ◽

Radiation Effects ◽

Vertical Plate ◽

Volume Fraction ◽

Fluid Velocity ◽

Skin Friction Coefficient ◽

Laplace Transform Technique ◽

Infinite Vertical Plate

An exact analysis is carried out to study the radiation effects on an unsteady natural convective flow of a nanofluid past an impulsively started infinite vertical plate. The nanofluids containing nanoparticles of aluminium oxide, copper, titanium oxide and silver with nanoparticle volume fraction range less than or equal to 0.04 are considered. The partial differential equations governing the flow are solved by Laplace transform technique. The influence of various parameters on velocity and temperature profiles, as well as Nusselt number and skin-friction coefficient, are examined and presented graphically. An increase in radiation parameter and time leads to fall in temperature of the fluid. The presence of nanoparticles and thermal radiation increases the rate of heat transfer and skin friction. The effect of heat transfer is found to be more pronounced in silver water nanofluid than in the other nanofluids. It is observed that the fluid velocity increases with an increase in Grashof number and time. Excellent validation of the present results is achieved with existing results in the literature.

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Experimental Research on Performance of Heat Transfer and Pressure Drop for Primary Surface Recuperator With Mini Channels

ASME 2011 Power Conference, Volume 2 ◽

10.1115/power2011-55437 ◽

2011 ◽

Author(s):

Hugen Ma ◽

Hui Gao ◽

Wenjing Tu

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Pressure Drop ◽

Experimental Research ◽

Transfer Factor ◽

Flow And Heat Transfer ◽

Good Consistency ◽

Mini Channels ◽

Performance Of Heat Transfer ◽

The Mathematical Model

Based on the single blow technique, experimental research was conducted for the performance of heat transfer and flow drop for six test cores with cross corrugated (CC) or corrugated undulated (CU) primary surfaces for different geometries. After the mathematical model was established for heat transfer under the condition of single blow, a matching numerical solution was obtained for different NTU. The correlations of hear transfer factor j and friction factor f were obtained for three types of cross corrugated primary surfaces (crossed angle 45∼75°) with a range of Re = 120∼800 and three types of corrugated undulated primary surfaces (crossed angle 52.5∼67.5°) with a range of Re = 200∼1200. Hydraulic diameters of all heat transfer surfaces are from 1.2∼1.48mm. Analysis on the flow and heat transfer for cross corrugated and corrugated undulated primary surfaces was made based on the comprehensive evaluating factor j/f. The experimental results were compared to references with good consistency. The regressive errors of correlations were less than 16%.

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Studi Perpindahan Panas Material pada Sistem Koordinat Segitiga

Prosiding SNFA (Seminar Nasional Fisika dan Aplikasinya) ◽

10.20961/prosidingsnfa.v1i0.4528 ◽

2017 ◽

Vol 1 ◽

pp. 114

Author(s):

Imam Basuki ◽

C Cari ◽

A Suparmi

Keyword(s):

Heat Transfer ◽

Mathematical Model ◽

Heat Conduction ◽

Partial Differential Equations ◽

Finite Difference ◽

Finite Difference Method ◽

Numerical Solution ◽

Difference Method ◽

The Finite Difference Method ◽

The Mathematical Model

Abstract: Partial Differential Equations (PDP) Laplace equation can be applied to the heat conduction. Heat conduction is a process that if two materials or two-part temperature material is contacted with another it will pass heat transfer. Conduction of heat in a triangle shaped object has a mathematical model in Cartesian coordinates. However, to facilitate the calculation, the mathematical model of heat conduction is transformed into the coordinates of the triangle. PDP numerical solution of Laplace solved using the finite difference method. Simulations performed on a triangle with some angle values α and β Keywords: heat transfer, triangle coordinates system. Abstrak Persamaan Diferensial Parsial (PDP) Laplace dapat diaplikasikan pada persamaan konduksi panas. Konduksi panas adalah suatu proses yang jika dua materi atau dua bagian materi temperaturnya disentuhkan dengan yang lainnya maka akan terjadilah perpindahan panas. Konduksi panas pada benda berbentuk segitiga mempunyai model matematika dalam koordinat cartesius. Namun untuk memudahkan perhitungan, model matematika konduksi panas tersebut ditransformasikan ke dalam koordinat segitiga. Penyelesaian numerik dari PDP Laplace diselesaikan menggunakan metode beda hingga. Simulasi dilakukan pada segitiga dengan beberapa nilai sudut dan Kata kunci : perpindahan panas, sistem koordinat segitiga.

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