Papers by Gbeminiyi Sobamowo
Thermal Science and Engineering Progress, 2020
Abstract In the present paper, a new hybrid method via the Laplace transform and Chebyshev Pseudo... more Abstract In the present paper, a new hybrid method via the Laplace transform and Chebyshev Pseudospectral collocation method is proposed. The proposed method is applied to analyse the transient thermal performance of a convective-radiative fin of functionally graded material under the effect of Lorentz force. The effects of Lorentz force, convective and radiative heat transfer on the thermal performance of the fin are analysed. From the parametric study, the thermal behaviour of the fin of functionally-graded material is established. The study shows that increase in the radiative and magnetic field parameters, as well as the non-homogeneity index, enhances the fin performance. Moreover, the transient thermal response of the fin is low at linear-law function whilst the thermal response is high at exponential-law function. The accuracy of the developed algorithm for the proposed method is validated using an established exact analytical solution. Excellent agreement is established from the result of the present study and the exact analytical method. The present study provides reliable physical insights into the heat transfer enhancement of microelectronic systems components operating in a convective-radiative environment.
Multidiscipline Modeling in Materials and Structures, 2020
PurposeIn this paper, hybrid multienzyme biosensor system, which detects analyte through molecula... more PurposeIn this paper, hybrid multienzyme biosensor system, which detects analyte through molecular conversion into signal response, is analyzed and presented. The biokinetic effects of pertinent parameters such as Michaelis–Menten constant, inhibitor inhibition and substrate inhibition modulus on biochemical reactions are investigated.Design/methodology/approachBiochemical reaction models are described by five nonlinear equations for bisubstrate amperometric system analyzed adopting the regular perturbation method.FindingsResults obtained reveal that increasing Michaelis–Menten constant of oxygen causes a significant decrease in hydrogen peroxide concentration while increasing Michaelis–Menten constant of glucose shows increasing effect on oxygen concentration. Hence, results obtained from this work serve as reference for further analysis of concentration models and offer useful insight to relevant applications such as food safety, environmental and biomedical applications.Practical...
The Journal of Engineering and Exact Sciences, May 24, 2023
Passive cooling of electronics systems requires the use of fins and spines. Improved heat transfe... more Passive cooling of electronics systems requires the use of fins and spines. Improved heat transfer enhancements in the systems have been achieved through porosity, magnetic field, functionally graded materials, etc. However, the space and time-dependent analysis of passive device with inherent nonlinearities and explorations of conditions at the tip have not been fully presented. Therefore, this work presents an application of hybrid computation analysis using combined methods of Laplace transformation and Legendre wavelet collocation to the space and timedependent nonlinear thermal models of a longitudinal conductive-radiative functionally graded extended surface. The spatial-dependent thermal conductivity is considered for three different cases. The present analysis results demonstrated good agreements with numerical results. The significances of the model pertinent parameters on the fin's performance are thoroughly considered and scrutinized by the aid of graphical illustrations. The fin tip thermal response decreases with increase in conductive-convective parameter, but it increases as time progresses. The inhomogeneity index is directly proportional to the FGM fin temperature. However, the convective term is inversely proportional to the fin's thermal distribution. The fin temperature under quadraticlaw heat conductivity of the passive device shows an enhanced performance of lower thermal distribution than the linear-and exponential-law heat conductivity. Ultimately, the study provides a very useful in the design of the fin with FGM.
The Journal of Engineering and Exact Sciences, May 28, 2021
This work presents approximate analytical solutions of nonlinear algebraic and transcendental equ... more This work presents approximate analytical solutions of nonlinear algebraic and transcendental equations through direct applications of Adomian decomposition method. The reliability and efficiency of the method in solving transcendental and nonlinear algebraic equations are demonstrated through different illustrative numerical examples. The method is shown to be conceptually and computationally simple and straightforward without any ambiguity. Also, the method as applied in this study shows that it does not require the development of any other iterative scheme that could be used to find the solution to the nonlinear equations. Additionally, the method does not require finding symbolic or numerical derivatives of any given function. With the use of the Adomian decomposition method, there is no search for an auxiliary parameter for adjusting and controlling the rate and region of convergence of the solution. The method does not require finding the correct fixed point and it is free from the problem of choosing an appropriate initial approximation. Therefore, it is hoped that the present work will assist in providing accurate solutions to many practical problems in science and engineering.
Aeronautics and Aerospace Open Access Journal
In this article, simultaneous impacts of surface elasticity, initial stress, residual surface ten... more In this article, simultaneous impacts of surface elasticity, initial stress, residual surface tension and nonlocality on the nonlinear vibration of single-walled carbon conveying nanotube resting on linear and nonlinear elastic foundation and operating in a thermo-magnetic environment are studied. The developed equation of motion is solved using Galerkin’s decomposition and Temini and Ansari method. The studies of the impacts of various parameters on the vibration problems revealed that the ratio of the nonlinear to linear frequencies increases with the negative value of the surface stress while it decreases with the positive value of the surface stress. The surface effect reduces for increasing in the length of the nanotube. Ratio of the frequencies decreases with increase in the strength of the magnetic field, nonlocal parameter and the length of the nanotube. Increase in temperature change at high temperature causes decrease in the frequency ratio. However, at room or low tempera...
WSEAS transactions on fluid mechanics, Dec 31, 2022
In this present work, the heat irreversibility analysis of thermal radiation, Ohmic heating, and ... more In this present work, the heat irreversibility analysis of thermal radiation, Ohmic heating, and angle of inclination on Williamson fluid is presented. The developed equations are converted to dimensionless forms, and Homotopy perturbation method (HPM) is used to solve the resulting coupled ordinary differential equations. The heat irreversibility analysis is achieved by substituting the obtained results into entropy generation and Bejan number expressions. The HPM solution for the velocity profile is validated by comparing it with a previously published study in some limited cases, and an excellent agreement is established. Fluid motion is accelerated by the increasing values of thermal radiation parameter, whereas the magnetic parameter and Reynolds number reduce it. Furthermore, except for the Weissenberg and Prandtl numbers, all of the flow parameters examined enhance fluid temperature. In addition, entropy generation is enhanced at the channel's upper wall for all parameters except magnetic field parameter.
Journal of Advanced Engineering and Computation
This current work mainly focuses on the enhancement of the heat transfer and fluid flow character... more This current work mainly focuses on the enhancement of the heat transfer and fluid flow characteristics of shell-and-tube heat exchangers by incorporating dimples on the smooth or conventional tubes. With the aid of the ANSYS (Fluent) commercial software package, Computational Fluid Dynamics (CFD) simulations under a steady-state condition were conducted on heat exchanger having a single shell and 12 tubes (with or without dimples), 50% baffle cut, 100mm baffle spacing and turbulent flow. The temperature, velocity, and pressure fields at the shell and tube zone in both cases are analyzed. The computational fluid dynamics results of the heat exchanger with dimpled tubes are compared with conventional (smooth) tubes. However, the results show that a shell and tube heat exchanger with dimpled tubes has a higher overall heat transfer coefficient than that of conventional (smooth) tubes. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens...
The increase in the utilization of high performance equipments has necessitated the use of lamina... more The increase in the utilization of high performance equipments has necessitated the use of laminated beams in aerospace engine, machine structures and electronic devices in order to dampen vibration and reduce noise. In such equipments, two laminates are pressed together and the occurrence of micro interfacial slip between these two laminates helps to effectively dissipate any unwanted vibration or noise. Also, when such structure are subjected to either static or dynamic loading, non-uniformity in interfacial pressure have significant effect on both the energy dissipated and the logarithmic damping decrement associated with the mechanism of slip damping. Thus, laminated beams can be effectively used to increase the level of damping available in such a mechanism. Hence, in this work, with the aid of Finite Difference Method, the effects of laminates on the energy dissipation due to frictional damping between the two laminates are investigated, so also the effects of the material pro...
In this paper, heat transfer study of porous fin with temperature-dependent thermal conductivity ... more In this paper, heat transfer study of porous fin with temperature-dependent thermal conductivity and internal heat generation is analyzed numerically using Legendre wavelet collocation method. The numerical solutions are used effects of nonlinear thermal conductivity, convective and porosity parameters on the thermal conductivity of the fin. The Legendre wavelet collocation method is verified with the results of numerical method using Runge-Kutta method and good agreements are established
In this study, Galerkin's method of weighted residual is used to present simple approximate analy... more In this study, Galerkin's method of weighted residual is used to present simple approximate analytical solutions to flow and heat transfer characteristics in a pipe conveying Johnson-Segalman fluid. The developed approximate analytical solutions are verified with the results in literature. Thereafter, the solutions are used to investigate the effects of the pertinent parameters such as relaxation time parameter, viscosity parameter and Brinkman number on the fluid velocity and the temperature distributions of the pipe flow. From the results, it shows that the fluid velocity and temperature increase with the relaxation time parameter and Brinkman number. It is also established that relaxation time parameter increases with increase in the velocity of the fluid but decreases with increase in the fluid temperature. It is found that the relaxation parameter effect on the velocity distribution are not significant as the viscosity parameter approaches unity and when it is greater than unity. It is hope that the study will provide more physical insight into the flow phenomena.
Thermal Science and Engineering Progress, 2021
Advanced Materials Research, 2020
Source-based method for modelling solidification problems have been modified and presented in the... more Source-based method for modelling solidification problems have been modified and presented in the current work. It coupled the effect of thermal radiation to macro-transport codes and was solved using finite volume method. The problem was formulated based on the classic continuum energy conservation equation for transient conduction controlled solidification system. Radiation heat transfer and latent heat evolution were added as source terms and solved with appropriate numerical treatments to obtain a system of linearized source terms. This circumvented the need for the application of any analytical solution to the intricate heat transfer regimes included in the model. The effect of cooling was carried out under various cooling conditions imposed on different surfaces of the mould for the solidifying metal. The resultant influence of cooling on the solid fraction evolution during static casting was then evaluated. The simulated cooling curves show that thermal radiation have no infl...
Iranian Journal of Science and Technology, Transactions of Civil Engineering, 2020
In this work, forced vibration analysis of isotropic thin circular plate resting on nonlinear vis... more In this work, forced vibration analysis of isotropic thin circular plate resting on nonlinear viscoelastic foundation is investigated. The dynamic analogue of the Von Kármán equations is used to establish the governing equations. The system coupled nonlinear partial differential equations are transformed to system of nonlinear ordinary differential equation using Galerkin decomposition method. Consequently, the analytical solutions are provided using differential transformation method with Padè Laplace after treatment technique. The developed solutions are verified using the existing results in the literature, and good agreement is observed. Subsequently, the analytical solutions are used to investigate the effects of various parameters on the dynamic response of the plate. From the results, it is observed that nonlinear frequency ratio of vibrating circular plate increases with increased linear elastic foundation and tensile force. Nevertheless, it is established that the nonlinear frequency ratio of the plate decreases as nonlinear Winkler foundation and compressive force increase. Also, the results revealed that clamped edge and simply supported edge condition recorded the same softening nonlinearity. However, axisymmetric case of vibration gives lower nonlinear frequency ratio compared to symmetric case. Also, maximum deflection occurs when excitation force is zero; likewise attenuation deflection is observed due to the presence of viscoelastic foundation. It is expected that the findings from this research will enhance the design of structures subjected to vibration under where circular plates are used. Keywords Vibration • Isotropic circular plate • Deflection • Nonlinear viscoelastic foundation • Differential transform method List of Symbols h Plate thickness ρ Mass density D Flexural rigidity of isotropic plate Ω Dimensionless natural frequency ν Poisson's ratio of isotropic plate Abbreviations a, b Dimension of the plate d dr First-order differential operator with respect to x w Transverse deflection x, y Rectangular space Cartesian coordinate along the length of thin plate
Defect and Diffusion Forum, 2020
Excess fin length results in material waste and additional weight leading to increased cost with ... more Excess fin length results in material waste and additional weight leading to increased cost with no benefit in return. Moreover, extra fin length affects the overall performance of the fin as fluid motion is suppressed, resulting in reduced convective heat transfer coefficient. To achieve a miniaturised system with effective cooling, the determination of appropriate length of extended surfaces becomes a key performance and fabrication process factor. Therefore, the present work aims at determining the proper or effective length of a convective-radiative moving fin of functionally graded material under the influence of a magnetic field. The developed governing equation of the analysis is solved analytically with the aid of Kummer’s function. The analytical solutions are used to investigate the effects of non-homogeneity, convective, radiative and magnetic parameter on the thermal performance and the proper fin length. The present study is hoped to assist in making cost-effective deci...
Journal of Energy, 2018
Nigeria has not been able to provide enough electric power to her about 200 million people. The l... more Nigeria has not been able to provide enough electric power to her about 200 million people. The last effort by the federal government to generate 6000 MW power by the end of 2009 failed. Even with the available less than 6000 MW of electricity generated in the country, only about 40% of the population have access to the electricity from the National Grid, out of which, urban centers have more than 80% accessibility while rural areas, which constitute about 70% of the total population, have less than 20% of accessibility to electricity. This paper addresses the possibility of meeting the energy demand in Nigeria through biomass gasification technology. The techno-economic analysis of biomass energy is demonstrated and the advantages of the biomass gasification technology are presented. Following the technical analysis, Nigeria is projected to have total potential of biomass of about 5.5 EJ in 2020 which has been forecast to increase to about 29.8 EJ by 2050. Based on a planned sellin...
International Journal of Engineering, 2019
The dynamic behaviour of a circular plate in contact with fluid and resting on two-parameter elas... more The dynamic behaviour of a circular plate in contact with fluid and resting on two-parameter elastic foundations is of interest in the field of geotechnics, structure, highway, railway, oil and gas and mechanical engineering. In this work, the dynamic behaviour of circular plate in contact with fluid and resting on Winkler and Pasternak foundations is investigated. The coupled differential equation of the system is analysed using differential transformation method. Good agreements are established when the results of the analytical solutions are compared to the results of the experimental investigation as reported in literature. The analytical solutions obtained are used to investigate the effects of elastic foundation parameters on natural frequency, combine foundation parameters on natural frequency, plate in contact with fluid and that of radial and circumferential stress on mode shapes. From the results, it is observed that, increases in elastic foundation parameter increases the natural frequency in all cases. Presence of fluid reduces the natural frequency of the plate. Also, it is established that mode shapes are not altered by the presence of fluid. However, mode shape displacement occurs due to presence of radial and circumferential stresses. Since the study provides a physical insight into the vibration mode of the structure, it is expected that the study will enhance better understanding on the dynamic behaviour of a circular plate in contact with fluid and resting on two-parameters elastic foundation.
Heat Transfer-Asian Research, 2019
The combined effect of particulate fouling and magnetic field on the efficiency of a convective-r... more The combined effect of particulate fouling and magnetic field on the efficiency of a convective-radiative porous fin heatsink with temperature-dependent thermal conductivity is presented. The developed thermal models are solved using differential transformation method. The effects of thermal conductivity, porosity, convection, radiation parameter, and thermal fouling number on the fin thermal efficiency are investigated. The presence of thermal fouling on the surface of the fin is shown to increase the temperature distribution. The presence of particle deposition on the fin surface significantly decreases the rate of heat transfer as additional thermal resistance of the fouling layer decreases the thermal performance of porous fin heatsink. Moreover, the fin efficiency decreases as the value of fouled Biot, Darcy, radiation number, and thermogeometric parameter increases. It is established that M f < M c , which indicates that the efficiency of the fouled fin is greater than the efficiency of the clean fin. Furthermore, the result of the present study is validated with the established results of Chebyshev spectral collocation method and fourth-order Runge-Kutta with shooting method and an error margin of 0.000000023 is established.
Physica A: Statistical Mechanics and its Applications, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Thermal Science and Engineering Progress, 2018
The advent of high-power electronic system components and slim margin errors require the proper u... more The advent of high-power electronic system components and slim margin errors require the proper understanding of particle deposition characteristics and its effects on the thermal performance of electronic heat sinks of electronic devices. In this work, we investigate the effects of particle deposition on the thermal performance of convective-radiative porous fin heat sink of an electronic component using Chebyshev spectral collocation method. The numerical solutions from the developed thermal models are also used to study the influence of thermal conductivity, porosity, convection, and radiation parameter on the temperature distribution and overall fin efficiency. The analysis establishes that presence of particles or thermal fouling on the surface of the fin increases the temperature distribution and temperature uniformity of the fin whilst decreasing the heat transfer rate from the fin. The study also establishes that decrease in heat transfer rate from the fin is due to the particle deposition on the fin, which depends on the particle size, particle density and cooling air flow rate. Moreover, the fin efficiency decreases with an increasing value of the fouled Biot, Darcy and radiation numbers, and thermo-geometric parameter. The study further shows that that the efficiency of the fouled porous fin is always greater than the efficiency of the clean porous fin. The analysis established that the result of Chebyshev spectral collocation method is in good agreement with that of the convectional numerical method using Runge-Kutta coupled with shooting method.
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Papers by Gbeminiyi Sobamowo