DEPARTMENT OF MECHANICAL ENGINEERING

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Author: search.filters.author.Ajide, O. O.End date: 2019

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Now showing 1 - 10 of 23
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    Numerical modelling of thermal distribution control in a furnace
    (2018) Petinrin, M. O.; Ajide, O. O.; Dare, A. A.; Oyewola, O. M.; Ismail, O. S.
    Application of control to heat treatment processes helps to achieve the desired mechanical properties of materials but improper controller design is a major problem causing short lifespan of components of locally made furnaces. In this study, the numerical control of the temperature distribution within a furnace cavity was carried out using COMSOL Multiphysics and Simulink. Six sensor points within the furnace cavity (with and without specimen) were selected and each point was consecutively used to observe the time response of the sensor to the desired temperature. The results from the time response analysis indicated uneven temperature distribution within the furnace with points located at the corners of the furnace recording the highest temperature rise while points at the centre of the furnace or within the specimen having the lowest temperature. Thus, the best position for a sensor is at any corner of the furnace to protect the components of the furnace from damage.
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    Microstructural characteristics of aluminum based composites developed by liquid metallurgyroute: an overview
    (2016-11) Ajide, O. O.; Oluwole, O. O.; Abu, R.; Petinrin, M. O.
    The extensive potential engineering applications of Aluminium Metal Matrix Composites (AMCs) are strong motivations for researchers renewed efforts in the development and characterisation of this class of material. The importance of microstructures for AMCs characterisation is enormous for reliable interpretations of its physical, mechanical, corrosion and thermal properties. Hence, a comprehensive review is quintessential in order to have a general overview of the influence and implications of microstructural characteristics on AMCs material properties. The review shows that an improved stir casting setup provides a reliable platform for effective and efficient stirring mechanism in the production of AMCs. This improved system is capable of reducing agglomerations to the barest minimum and thus promotes homogeneous dispersion of ceramic reinforcement particles in the matrix. The nature of AMCs microstructures have specific implications to its mechanical, corrosion and wear properties. The formation of pores, pits, rough surface and ceramics particles agglomerations in AMCs microstructures are manifestations of severe corrosion of the composites in different environments. The microstructural characteristics of corroded composite samples are aggravated by the harshness of the corrosion environments and increase in the percentage weight fractions of most ceramic reinforcement particles. The type of ceramic reinforcement particles used in AMCs has been well reported in the literature to have immense influence on its microstructural characteristics. Further, the review was able to show that heat treatment is a reliable process that can be explored in enhancing the homogeneous dispersion of reinforcement particles in AMCs matrix and its overall microstructural features. This review has enriched researchers’ understanding on immense benefits of AMCs microstructural examinations and its numerous implications. It is hopeful that this will be an illuminating platform for intensifying research activities on the microstructural characterisation of AMCs. The conclusion that can be drawn from this in-depth overview is that microstructural examinations will remain one of the leading techniques for AMCs materials properties characterisation. Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) will continue to be the domineering microstructural examinations techniques for characterising the material properties of AMCs.
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    Numerical analysis of thermo-elastic contact problem of disc brakes for vehicle on gradient surfaces
    (Scientific Research Publishing, 2016-12) Petinrin, M. O.; Oyedele, A. A.; Ajide, O. O.
    In this study, the thermo-elastic effects of frictional heat generation in a disc brake system due to braking actions were simulated. The mathematical model that defined the problem was developed from the kinetic and potential energies of moving vehicles on the gradient surfaces. This problem was solved for the selected geometry of disc brake and pad with their material properties selected from existing literatures using the finite element method and the computational results were obtained. The thermal deformation obtained was in good agreement with similar literature results.Also, for the same braking period and conditions, the results showed that a vehicle ascending a hill gave a higher temperature rise, Von Mises stress and thermal deformation on brake contact surfaces than when descending hill. Therefore, the braking period required to bring a moving vehicle in ascendent motion to a lower speed is expected to be shorter because of the gravity effect than horizontal motion, while descendent motion requires longer braking period.
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    Comparative study of corrosion behaviour of nickel and gold plated carbon steels used as ornamentals in saline environment
    (Science and Academic Publishing, 2012) Oluwole, O. O.; Garus-Alaka, W.; Ajide, O. O.
    This study investigated the corrosion resistance of plated and unplated steels useful as ornamentals in saline environment. Nickel plating of carbon steel was done in watts solution for 25minutes with a current density of 3 Adm-3 at 60oC. The nickel plated carbon steel was later gold plated for 20 minutes with a current density of 0.2 Adm-3 at 50oC . The plated and unplated carbon steels were immersed in saline environment for 360 hours. Weight loss was taken every 24 hours in order to evaluate corrosion penetration rate (CPR). The results obtained showed that plated carbon steel generally offers a better corrosion resistance than the unplated one. Corrosion of ornamentals is equally gaining importance especially coated ornamentals. The use of nickel for ornamentals is gaining more prominence over silver rising due to its shiny surface and its cost. The use of nickel plated ornamentals just as gold plated ornamentals are being patronized will surely become common place due to affordability for the generality of people. However, the effects of everyday corrosive fluids from kitchen salt and low acidic media on the durability of the coatings need to be established. Carbon steel is the natural substrate used in ornamental coatings .The results also showed that a small thickness of gold plated carbon steel exhibited better corrosion resistance in saline environment. More also, gold plated carbon steel is found to be more suitable and reliable candidate material than nickel plated carbon steel in this environment although with higher costs.
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    Comparative study of corrosion behaviour of nickel and gold plated carbon steels used as ornamentals in saline environment
    (Science and Academic Publishing, 2012) Oluwole, O. O.; Garus-Alaka, W.; Ajide, O. O.
    This study investigated the corrosion resistance of plated and unplated steels useful as ornamentals in saline environment. Nickel plating of carbon steel was done in watts solution for 25minutes with a current density of 3 Adm-3 at 60oC. The nickel plated carbon steel was later gold plated for 20 minutes with a current density of 0.2 Adm-3 at 50oC . The plated and unplated carbon steels were immersed in saline environment for 360 hours. Weight loss was taken every 24 hours in order to evaluate corrosion penetration rate (CPR). The results obtained showed that plated carbon steel generally offers a better corrosion resistance than the unplated one. Corrosion of ornamentals is equally gaining importance especially coated ornamentals. The use of nickel for ornamentals is gaining more prominence over silver rising due to its shiny surface and its cost. The use of nickel plated ornamentals just as gold plated ornamentals are being patronized will surely become common place due to affordability for the generality of people. However, the effects of everyday corrosive fluids from kitchen salt and low acidic media on the durability of the coatings need to be established. Carbon steel is the natural substrate used in ornamental coatings .The results also showed that a small thickness of gold plated carbon steel exhibited better corrosion resistance in saline environment. More also, gold plated carbon steel is found to be more suitable and reliable candidate material than nickel plated carbon steel in this environment although with higher costs.
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    Investigating corrosion charateristics of Electroplated medium carbon steel in sodium carbonate environment for decorative objects applications
    (IJET Publications UK., 2013-03) Oluwole, O. O.; Garus-Alaka, W.; Ajide, O. O.
    The main objective of this study is to investigate the corrosion resistance characteristics of electroplated Medium Carbon Steel (MCS) in 0.5mol/dm3 Sodium Carbonate environment. Nickel plating of MCS was done in watts solution for 25 minutes with a current density of 3 A/dm3 at 60oC. The nickel plated MCS was later gold plated for 20 minutes with a current density of 0.2 A/dm3 at 50oC . The plated and unplated MCS were exposed to sodium carbonate environment for 360 hours. The weight loss was taken every 24 hours in order to estimate corrosion penetration rate (CPR). The results obtained showed that plated MCS generally showed a better corrosion resistance than the unplated one. Although gold plated MCS has a slightly better corrosion resistance characteristic than nickel plated one, the conclusion that can be drawn from this study is that Nickel and Gold plated medium carbon steels are found to be both reliable materials for decorative objects applications in sodium carbonate environment.
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    Development of a field-portable digital potentiostat
    (2012) Oluwole, O. O.; Adegoke, T. O.; Ajide, O. O.
    The use of potentiostats for corrosion rate studies and activation polarization is very crucial because the weight loss method is limited in corrosion studies. However, commercial potentiostats are expensive for most end users. For these reasons, it was desirable to design and build an inexpensive field-portable potentiostat to interface with electrochemical cell. This paper present the proceeudre and design principles of a portable, digital and inexpensive potentiostat, its construction and testing PROTEUS software was used in the design of the different components of the potentiostate and simulation of the tested in a corrosion cell in which a mild steel working electrode (WE) was immersed in 5% NaCl solution. Ag/ AgCl exchange current density (io of mild steel, |Fe/Fe2) of 1.5 X10-6 A/ cm2, standard potential of ,mild steel (Eo mildsteel) of -0.42V and corrosion penetration rate (CPR) at io of 9.18x10-7 cm/hr and Taffel β value of 0.13V was obtained for mild steel in 5% NaCl solution. The values of OCP, ioEo, CPR and β were consistent with values obtained form literature.
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    Corrosion analysis of nickel and gold plated carbon steel ornamentals in sulphuric acid meduim
    (2012) Oluwole, O. O.; Garus-Alaka, W.; Ajide, O. O.
    This study investigated the corrosion resistance of Nickel and Gold plated carbon steels ornamentals in 0.5mol/dm3Suphuric acid(H2SO4) medium. Nickel plating of carbon steel was done in watts solution for 25minutes with a current density of 3 A/dm3 at 60oC. The nickel plated carbon steel was later gold plated for 20 minutes with a current density of 0.2A/dm3 at 50oC.The plated and unplated carbon steels were exposed to H2SO4 environment for 15 days. The weight loss was taken every 24 hours in order to evaluate corrosion penetration rate(CPR). The results obtained showed that plated carbon steel generally offered a better corrosion resistance than the unplated carbon steels. The conclusion that can be drawn from this study is that Nickel plated carbon steel is found to be more reliable material to be used as ornamentals than gold plated carbon steel in H2SO4 enviroment
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    Energy audit of commercial buildings (a case study of global fleet oil ltd. and national mirror houses
    (2012) Elusakin, J. E.; Ajide, O. O.; Salau, T. A. O.; Idowu, O. G.
    "The dearth and cost of energy supply in Nigeria calls for planning and management through energy audit. The object of this paper is to carry out a comprehensive energy audit of the two commercial buildings commonly referred to as Energy House and Mirror House which are the head offices of the Global Fleet Oil & Gas Ltd. Company and National Mirror Newspaper respectively, using their 2011 energy consumption data. The power supplies to both offices are from the same generators which provide two third of the power supply to the building in 2011 but with different transformers of 1000 kV A each for the PHCN power supply. The facilities load were assessed by direct inspection and conversion were done where necessary. The capacities of the available three generators were 400, 640 & 1000 kW respectively (using 0.8 power factor) and the maximum load of the facility at any time in a day is 398 kW. This study has revealed the monumental financial waste on the un-utilized energy and facilities that could be replaced with energy saver equipment. Therefore, it is imperative that a holistic energy planning and regular assessment of energy requirements are considered as key components of building projects. "
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    Development and investigation of Runge-Kutta coefficients depenedent stability polynomial
    (2013-07) Salau, T. A. O.; Ajide, O. O.
    "Simulation of reliable solutions of nonlinear engineering problems by means of stable numerical algorithms is a frequent and acceptable practice. This study focuses the development and investigation of Runge-Kutta coefficients dependent stability polynomial for the second, third and fourth orders Runge-Kutta schemes. The development utilized matrix inversion operation procedure that involves determinant and cofactors computation of relevant matrix. The validation was made referencing the standard result of [1] and extended to several cases. The resulting polynom ials obtained consist of combination of the scheme coefficients with increasing power of time step that follows a rhyme pattern.The validation test case result agreed perfectly with test standard result. Selected studied version of different schemes shows wide variation in the shape of stability curve and region bounded. It is interesting to note that the popular second, third and•fourth order schemes have stability curve that bounded larger region than their respective counterpart. It is concluded that the study results can be utilized as reliable platform for stability analysis for different versions of the second, third and fourth order schemes. "