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1 – 10 of 150Jawad Raza, Mohsin Raza, Tahir Mustaq and Muhammad Imran Qureshi
The purpose of this paper is to study the thermal behavior of radial porous fin surrounded by water-base copper nanoparticles under the influence of radiation.
Abstract
Purpose
The purpose of this paper is to study the thermal behavior of radial porous fin surrounded by water-base copper nanoparticles under the influence of radiation.
Design/methodology/approach
In order to optimize the response variable, the authors perform sensitivity analysis with the aid of response surface methodology (RSM). Moreover, this study enlightens the applications of artificial neural networks (ANN) for predicting the temperature gradient. The governing modeled equations are firstly non-dimensionalized and then solved with the aid of Runge–Kutta fourth order together with the shooting method in order to guess the initial conditions.
Findings
Numerical results are analyzed and presented in the form of tables and graphs. This study reveals that the temperature of the fin is decreasing as the wet porous parameter increases (m2) and the temperature for 10% concentration of nanoparticles are higher than 5 and 1%. Physical parameters involved in the study are analyzed and processed through RSM. It is come to know that sensitivity of temperature gradient to radiative parameter (Nr) and convective parameter (Nc) is positive and negative to dimensionless ambient temperature (θa). Furthermore, after ANN training it can be argued that the established model can efficiently be used to predict the temperature gradient over a radial porous fin for the copper-water nanofluid flow.
Originality/value
To the best of our knowledge, only a few attempts have been made to analyze the thermal behavior of radial porous fin surrounded by copper-based nanofluid under the influence of radiation and convection.
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Sowmya G., Gireesha B.J. and Prasannakumara B.C.
The purpose of this paper is to study the thermal behaviour of radial porous fin wetted with nanofluid containing different shaped nanoparticles in the presence of natural…
Abstract
Purpose
The purpose of this paper is to study the thermal behaviour of radial porous fin wetted with nanofluid containing different shaped nanoparticles in the presence of natural convection and radiation. Here, the nanofluid suspended with molybdenum disulfide nanoparticle with base fluid as water is considered. The influence of non-spherical nanoparticles such as platelet, cylinder, brick and blade shapes is also investigated.
Design/methodology/approach
The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme.
Findings
The flow natures of the pertinent parameter are represented graphically and discussed their physical significance. From the validation of obtained outcome, it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.
Originality/value
The present paper deals with an analysis of the flow of molybdenum disulfide nanoparticles suspended in water over a porous fin of a radial profile. The effect of differently shaped nanoparticles on the heat transfer enhancement through the radial porous fin is investigated for the first time. The natural convection and radiation effects are also considered. The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. The effect of pertinent parameters on temperature field is examined. From the validation of obtained outcome it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.
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B.J. Gireesha, G. Sowmya and Madhu Macha
This paper aims to study the temperature performance with natural convection and radiation effect on a porous fin in fully wet condition.
Abstract
Purpose
This paper aims to study the temperature performance with natural convection and radiation effect on a porous fin in fully wet condition.
Design/methodology/approach
The finite element method (FEM) is applied to generate numerical solution of the obtained non-dimensional ordinary differential equation containing highly nonlinear terms. The parameters which impact on the heat transfer of fin have been scrutinized by means of plotted graphs.
Findings
The porous fin is taken for the analysis in radial profile moving with constant velocity. Here, the thermal conductivity is considered to be temperature dependent. The Darcy’s model has been implemented to study the heat transfer analysis.
Originality/value
The paper is genuine in its type, and there are hardly any works on fins as per the authors’ knowledge.
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G. Sowmya, B.J. Gireesha and O.D. Makinde
The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been…
Abstract
Purpose
The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been scrutinised along with the simultaneous variation of surface emissivity, heat transfer coefficient and thermal conductivity with temperature. The emissivity of the surface and the thermal conductivity are considered as linear functions of the local temperature between fin and the ambient. Darcy’s model was considered to formulate the heat transfer equation. According to this, the porous fin permits the flow to penetrate through it and solid–fluid interaction occurs.
Design/methodology/approach
Runge–Kutta–Fehlberg fourth–fifth-order method has been used to solve the reduced non-dimensionalized ordinary differential equation involving highly nonlinear terms.
Findings
The impact of pertinent parameters, such as convective parameter, radiative parameter, conductivity parameter, emissivity parameter, wet porous parameter, etc., on the temperature profiles were elaborated mathematically with the plotted graphs. The heat transfer from the fin enhances with the rise in convective parameter.
Originality/value
The wet nature of the fin enhances heat transfer and in many practical applications the parameters, such as thermal conductivity, heat transfer coefficient as well as surface emissivity, vary with temperature. Hence, the main objective of the current study is to depict the significance of simultaneous variation in surface emissivity, heat transfer coefficient and thermal conductivity with respect to temperature under natural convection and radiation condition in a totally wetted longitudinal porous fin.
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M.T. Darvishi, Rama Subba Reddy Gorla, F. Khani and B.J. Gireesha
The purpose of this paper is to take the thermal analysis of natural convection and radiation heat transfer in fully wet porous fins. The wet porous fins taken for the analysis…
Abstract
Purpose
The purpose of this paper is to take the thermal analysis of natural convection and radiation heat transfer in fully wet porous fins. The wet porous fins taken for the analysis are straight fins in nature and wet. Their profile being straight helps heat transfer process of fins faster. The analysis is performed using the Darcy’s model to generate the heat equation to analyze the variation of convection and radiation parameters. The porous nature of the fins allows the flow to penetrate through the porous material of the fins leading to solid-fluid interface. The obtained non-dimensional ordinary differential equation involving three highly nonlinear terms are solved numerically by using spectral collocation method after which they are reduced into algebraic equations using Chebyshev polynomials. The study is analyzed using the mathematical analysis on heat equation and generating graphs for finding the parameters important to the heat transfer in the straight fins.
Design/methodology/approach
This study is performed using Darcy’s model to formulate heat transfer equation. To study the thermal performance, the authors considered a finite length fin with insulated tip. The effects of the wet fin parameter m2, porosity parameter Sh, radiation parameter G and temperature ratio CT on the dimensionless temperature distribution and heat transfer rate are discussed.
Findings
The results show that the base heat flow increases when the permeability of the medium is high and/or when the buoyancy effect induced in the fluid is strong.
Research limitations/implications
The analysis is made for the Darcy’s model. Non-Darcy effects will be investigated in a future work.
Practical implications
The approach is useful in enhancing heat transfer rates.
Originality/value
The results of the study will be interest to the researchers of the field of heat exchanger designers.
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G. Sowmya, Gireesha B.J., Muhammad Ijaz Khan, Shaher Momani and Tasawar Hayat
The purpose of this study is to conduct a numerical computation to analyse the thermal attribute and heat transfer phenomenon of a fully wetted porous fin of a longitudinal…
Abstract
Purpose
The purpose of this study is to conduct a numerical computation to analyse the thermal attribute and heat transfer phenomenon of a fully wetted porous fin of a longitudinal profile. The fin considered is that of a functionally graded material (FGM). Based on the spatial dependency of thermal conductivity, three cases such as linear, quadratic and exponential FGMs are analysed.
Design/methodology/approach
The governing equations are nondimensionalised and solved by applying Runge-Kutta-Fehlberg fourth-fifth order technique.
Findings
The parametric investigation is executed to access the significance of the pertinent parameters on the thermal feature of the fin and heat transmit rate. The outcomes are portrayed in a graphical form.
Originality/value
No such study has yet been published in the literature.
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Bhupendra Kumar Sharma, Umesh Khanduri, Rishu Gandhi and Taseer Muhammad
The purpose of this paper is to study haemodynamic flow characteristics and entropy analysis in a bifurcated artery system subjected to stenosis, magnetohydrodynamic (MHD) flow…
Abstract
Purpose
The purpose of this paper is to study haemodynamic flow characteristics and entropy analysis in a bifurcated artery system subjected to stenosis, magnetohydrodynamic (MHD) flow and aneurysm conditions. The findings of this study offer significant insights into the intricate interplay encompassing electro-osmosis, MHD flow, microorganisms, Joule heating and the ternary hybrid nanofluid.
Design/methodology/approach
The governing equations are first non-dimensionalised, and subsequently, a coordinate transformation is used to regularise the irregular boundaries. The discretisation of the governing equations is accomplished by using the Crank–Nicolson scheme. Furthermore, the tri-diagonal matrix algorithm is applied to solve the resulting matrix arising from the discretisation.
Findings
The investigation reveals that the velocity profile experiences enhancement with an increase in the Debye–Hückel parameter, whereas the magnetic field parameter exhibits the opposite effect, reducing the velocity profile. A comparative study demonstrates the velocity distribution in Au-CuO hybrid nanofluid and Au-CuO-GO ternary hybrid nanofluid. The results indicate a notable enhancement in velocity for the ternary hybrid nanofluid compared to the hybrid nanofluids. Moreover, an increase in the Brinkmann number results in an augmentation in entropy generation.
Originality/value
This study investigates the flow characteristics and entropy analysis in a bifurcated artery system subjected to stenosis, MHD flow and aneurysm conditions. The governing equations are non-dimensionalised, and a coordinate transformation is applied to regularise the irregular boundaries. The Crank–Nicolson scheme is used to model blood flow in the presence of a ternary hybrid nanofluid (Au-CuO-GO/blood) within the arterial domain. The findings shed light on the complex interactions involving stenosis, MHD flow, aneurysms, Joule heating and the ternary hybrid nanofluid. The results indicate a decrease in the wall shear stress (WSS) profile with increasing stenosis size. The MHD effects are observed to influence the velocity distribution, as the velocity profile exhibits a declining nature with an increase in the Hartmann number. In addition, entropy generation increases with an enhancement in the Brinkmann number. This research contributes to understanding fluid dynamics and heat transfer mechanisms in bifurcated arteries, providing valuable insights for diagnosing and treating cardiovascular diseases.
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Vishweshwara P.S., Harsha Kumar M.K., N. Gnanasekaran and Arun M.
Many a times, the information about the boundary heat flux is obtained only through inverse approach by locating the thermocouple or temperature sensor in accessible boundary…
Abstract
Purpose
Many a times, the information about the boundary heat flux is obtained only through inverse approach by locating the thermocouple or temperature sensor in accessible boundary. Most of the work reported in literature for the estimation of unknown parameters is based on heat conduction model. Inverse approach using conjugate heat transfer is found inadequate in literature. Therefore, the purpose of the paper is to develop a 3D conjugate heat transfer model without model reduction for the estimation of heat flux and heat transfer coefficient from the measured temperatures.
Design/methodology/approach
A 3 D conjugate fin heat transfer model is solved using commercial software for the known boundary conditions. Navier–Stokes equation is solved to obtain the necessary temperature distribution of the fin. Later, the complete model is replaced with neural network to expedite the computations of the forward problem. For the inverse approach, genetic algorithm (GA) and particle swarm optimization (PSO) are applied to estimate the unknown parameters. Eventually, a hybrid algorithm is proposed by combining PSO with Broyden–Fletcher–Goldfarb–Shanno (BFGS) method that outperforms GA and PSO.
Findings
The authors demonstrate that the evolutionary algorithms can be used to obtain accurate results from simulated measurements. Efficacy of the hybrid algorithm is established using real time measurements. The hybrid algorithm (PSO-BFGS) is more efficient in the estimation of unknown parameters for experimentally measured temperature data compared to GA and PSO algorithms.
Originality/value
Surrogate model using ANN based on computational fluid dynamics simulations and in-house steady state fin experiments to estimate the heat flux and heat transfer coefficient separately using GA, PSO and PSO-BFGS.
Felicita Almeida, B.J. Gireesha, P. Venkatesh and G.K. Ramesh
This study aims to investigate the flow behavior of aluminum oxide–water nanofluid with variable viscosity flowing through the microchannel parallel with the ground, with low…
Abstract
Purpose
This study aims to investigate the flow behavior of aluminum oxide–water nanofluid with variable viscosity flowing through the microchannel parallel with the ground, with low aspect ratio. The study focuses on the first and second law analyses of Poiseuille flow using water as the base fluid with alumina nanoparticles suspended in it. Combined effects of thermal radiation, viscous dissipation, variable viscosity, nanoparticle shape factor and volume fraction on the thermal performance are studied and the in-built irreversibility in the process is examined.
Design/methodology/approach
The governing equations with dimensions are reduced to non-dimensional equations by using dimensionless quantities. Then, the Runge–Kutta–Fehlberg shooting scheme tackles the present non-linear equations.
Findings
The outcomes of the present analysis reveal that the activation energy parameter with its increase, depletes the exergetic effectiveness of the system, thus defending the fact to keep the activation energy parameter the lowest as possible for the system efficiency. In addition, thermal radiation and Biot number enhance the release of heat energy, thereby cooling the system. Bejan number graph exhibits the decreasing behavior for the increased nanoparticle shape factor, whereas the temperature enhances with the rise in nanoparticle shape factor.
Originality/value
The effects of nanoparticle shape factor in Poiseuille flow for alumina–water nanoliquid in low aspect ratio microchannel is inspected at the earliest. Exergetic effectiveness of the system is studied and heat transfer characteristics are explored for thermal radiation effect and activation energy parameter. Besides,
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Zahra Ebrahimpour, Mohsen Sheikholeslami, Seyyed Ali Farshad and Ahmad Shafee
This paper aims to model solar unit equipped with mirrors with numerical simulation. To augment the efficiency of system, absorber pipe was equipped with fins and nanomaterial was…
Abstract
Purpose
This paper aims to model solar unit equipped with mirrors with numerical simulation. To augment the efficiency of system, absorber pipe was equipped with fins and nanomaterial was used as carrier fluid. Existence of secondary reflector results in better optical efficiency.
Design/methodology/approach
Finite volume approach is used for modeling which is done in two steps. The first one is done to achieve the heat flux distribution and second step to model turbulent flow inside the pipe. Verification has been presented for calculation of important functions (f and Nu). Outputs reveal the impacts of fin height (HF), number of fin (NF), inlet temperature (Tin) and velocity on irreversibility, thermal treatment.
Findings
Surface temperature decreases by 0.498, 0.07 and 0.017% with intensify of Re, HF and NF, respectively, when other factors were minimum. With augment of Tin, wall temperature increases about 9.87%. Given NF = 8, HF = 3 mmm, growth of Re makes Darcy factor to decrease about 28.28%, but it augments the Nu by 2.63%. Nu augments with rise of NF and HF about 2.63 and 7.66%. Irreversibility reduces about 29.5 and 11.65% with augment of NF and HF, respectively.
Originality/value
Numerical simulations for solar unit equipped with mirrors were reported in this modeling. To augment the efficiency of system, absorber pipe was equipped with fins and nanomaterial was used as carrier fluid. Existence of secondary reflector results in better optical efficiency. Finite volume approach is used for modeling which is done in two steps. The first one is done to achieve the heat flux distribution and second step to model turbulent flow inside the pipe. Verification has been presented for calculation of important functions (f and Nu). Outputs reveal the impacts of fin height (HF), number of fin (NF), inlet temperature (Tin) and velocity on irreversibility, thermal treatment.
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