DEPARTMENT OF MECHANICAL ENGINEERING

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3-D geometric modeling for finite element analysis using MATLAB® C programming
(2012) Eyere, E.; Oluwole, O.
Most finite element analysts in Nigeria develop own codes for their analysis due to inability to purchase commercial finite element analysis software packages that come with GUI geometric modelers and difficulty in managing coordinate data from imported CAD files. General purpose computer-aided design software packages are good drafting tools but do not have imbedded facilities to carry out finite element analyses of descretized (mesh) models. This paper demostrates how MATLAB® programming language can be used to generate 3-D geometric models suitable for finite element anaylsis. In this work, model of a water storage tanker was drawn using AutoCAD®, and then the same model was generated using MATLAB®. The results showed that MATLAB® can be used to obtain meshed and surface model suitable for finite element analysis.
Accurate safty zone detemination during gas flaring
(Medwell Journals, 2009) Ismail, O. S.; Fagbenla, R. O.
Gas flaring, a long-established but unacceptable practice in the Nigerian Petroleum industry, has deleterious effects on the environment. Research efforts have concentrated on using empirical formulae derived from experiments in predicting heat fluxes around a gas flare. However numerical method, which is capable of eliminating the severe inaccuracies in calculation from empirical formulae, is yet to be explored. The flare was considered as a three-dimensional turbulent jet issuing into a continuous cross flow of air. The momentum and scalar fluxes were approximated by the k-ε turbulence model and the resultant conservation equations were solved using the finite volume technique. The laminar flamelet concept was used to characterize the local thermochemical state of the combusting mixture, while the discrete transfer method was used to compute the radiative heat flux. A model for an accurate prediction of the heat flux at any point within the vicinity of a gas flare was developed. Thermal radiation profiles predicted at ground level exhibited Gaussian behaviour. Deviation of the predicted flux result at ground level estimated by the empirical formulae were between 15.0 and 35.0%. Based on the existing standard for maximum allowable radiation flux of 6.3 kW m-2, the model minimum safest distance from the flare was 1.1 m, whilst the empirical formulae gave minimum safest distances ranging between 0.8 and 1.4 m. This model had superior prediction capabilities than the existing empirical formulae. Safe distances could be deduced from heat flux standpoint for both humans and habitat using the model.
Activated carbon from agricultural waste: process description and economic analysis
(2009) Oiogun, O. O.; Oyekeye, O. M.; Odesola, I. F.
Adsorption refrigeration technology has been intensively investigated in many countries of the world because of its promising potential for competing with conventional vapour compression refrigeration, its relatively low operating cost and its environmental friendliness. The search for a good adsorbent for solar powered refrigeration technology has led to various attempts to manufacture activated carbon of high adsorptive property. In this study coconut shells plus 10% animal bones, agricultural wastes, were used as basic raw materials for the local production of activated carbons. The properties determined were the particle size diameter, iodine no, hardness no, bulk density, and tamped density of the activated carbon samples. The results for the coconut shells only of mesh size 14 and maximum particle size of 2.36mm are: iodine no, 906.68mg/g, hardness no, 1, bulk density, 0.504g/ml, tamped density, 0.562g/ml and ash content, 0.012%; while that of the coconut shells with 10% bones of mesh size 14 and maximum particle size of 2.36mm are: iodine no, 870.51mg/g, hardness no, 1, bulk density, 0.585g/ml, tamped density, 0.604g/ml and ash content, 0.06%. In comparison with the imported activated carbons these can be classified as medium grade carbons, This work has established the fact that activated carbons, the principal component for solar powered refrigeration technology can be locally sourced without compromising standards.
Activated carbon production from wastes: profitability index and product cost reduction method
(2010) Odesola, I. F.; Daramola, N. O.
A previous paper on developing a national capability for the manufacture of activated carbon from agricultural waste by the same authors was considered. In the said paper, the process flow diagram for the manufacture of Granular Activated Carbon from three agricultural wastes namely coconut shell, oil-palm shells and sugarcane bagasse was provided and the plant’s economic analysis done. The objectives of this study were to investigate selling price reducing options and profitability of the investment discussed. In the study, the profitability indexes for the overall plant projects for the three plants were found. The effect of equipment cost reduction on the total productive cost was also examined. For the steam activation of coconut shell, successive reduction by 10% in the overall equipment cost was found reduce the corresponding Product cost geometrically by values ranging from 2.44-1.22% for ten successive reductions. The profitability index was between 0.057 and 4.07% respectively for the 1st to the 11th year. The steam activation of sugarcane bagasse was different, successive reduction by 10% in the overall equipment cost reduce the corresponding Product cost also geometrically by values ranging from 2.85-3.69% (increasing with each reduction) also for 10 successive reductions. The profitability index was between 0.09 and 3.7% respectively for the 1st to the 11th year. And for the phosphoric activation of oil-palm shell, successive reduction by 10% in the overall equipment cost was found reduce the corresponding Product cost geometrically by values ranging from 4.58-2.88% (decreasing with each reduction as in steam activation of coconut shells). The profitability index was between -1.08 and 2.12% respectively for the 1st to the 11th year. In addition, an excel software to simulate the economic analysis previously done and output the key costs after the simulation.
Adaptation of Ushafa clay, Abuja, as a suitable replacement for bentonite in the foundry industry
(2008) Atanda, P. O.; Oluwole, O. O.; Ogale, O. T.
This work investigated the possible use of Ushafa clay in Abuja, Nigeria as a suitable replacement for bentonite clay in foundry use. Moulding sand mixes with compositions of 8,10 and 13%. Ushafa clay, silica sand and 5,7,8,9,10 and 11% coal dust additives were mulled. From each mix, cylindrical specimens were prepared and subjected to permeability, shatter index, compression and shear strength tests . The results from the Ushafa mix were compared with results from bentonite mixes. The results showed that moulding sand compositions having 13%. Ushafa clay, and coal dust additions of 8% produced specimens with good permeability, dry strength, green strength and collapsibility for foundry use. This work has confirmed the possible use of Ushafa clay as suitable replacement for bentonite binder in foundry
Aircraft Disasters- roles of materials
(2009) Asafa, T. B.; Durowoju, M. O.; Ismail, O. S.
Aircraft disaster has been in existence since air was conquered by man as a means of transportation. 487.5 million and 874.4 millions of cumulative departures and flight hours respectively have been estimated since 1959. Analysis of aircraft failure based on 5,149 on-board fatalities recorded shows that 13% of total aircraft accident was caused by mechanical failure while loss of control was responsible for over 31% of onboard fatalities. Aircraft accident is known to be most fatal during take-off and landing phase contributing about 49% while onboard fatality during cruise is about 19%. In this work, reviews of aircraft disasters were made via Fractographic examination, SEM and finite element modeling. It must be stated that few of aircraft failures which are not material related are not considered in this review. The review focused on material related failure which have been analyzed, accepted and published in reputable journals.
Aluminium anode activation research- a review
(2012) Idusuyi, N.; Oluwole, O. O.
The aim of this paper is to review aluminum anode formulation and activating elements till date and discuss the possibility of further work based on recent trends in the use of nano or agro based materials. The performance of aluminum anodes is largely dependent on alloy composition and a good understanding of the relationships between the metallurgy and the anodic response of the alloys. Recent researches show that microalloying aluminum anodes with certain metallic composite oxides can significantly improve anode life and reduce costs. Suggestions for further work are also presented.
Analyses and modeling of laminar flow in pipes using numerical approach
(Scientific Research, 2012) Ismail, O. S.; Adewoye, G.T
This paper investigate some important works done on numerical analysis and modeling of laminar flow in pipes.This review is focused on some methods of approach and the analytical tools used in analyzing of the important parameters to be considered in laminar flow; such as frictional losses, heat transfer etc. in laminar flow in pipes of different shapes, and the importance of laminar flow in its areas of applications. Prominent researchers have approached this from different perspectives. Some carried out analysis on the pressure drop as a function of permeability, some worked on friction factor analysis, some discussed heat transfer effects of laminar flow in the entrance region, while some discussed its applications in various industries. Some of these works were done considering a given form of pipe configuration or shape which is circular pipes. Only a few, of the literature reviewed have related their considerations to different forms of pipes. Most consider pipes to be majorly circular in shape, but in industries today some circular pipes have become elliptical in shape due to long time usage of the pipes, which would have contributed to increase in some different forms of losses in the industries. In engineering, efficiency and effectiveness improvement is the major goal, if a research work has been done, considering the important parameters in laminar flow showing their effects on different forms of pipe configuration as a result of pipe deformation due to usage, huge amount of money will be saved. This will show clearly how the efficiency of a given circular pipe has seriously been affected due to deformation, and the level of loss this has resulted to.
Analysis of traffic inflow to a university campus in a developing country:a rescale range approach
(2007-10) Alabi, B.; Salau, T. A. O.; Oke, S. A.
"All over the world, there is an increasing enrolment level for university admissions in view of the ever-increasing benefits of earning university degrees. Thus, the high population of students in many universities, coupled with a high number of vehicles has made traffic control a challenge to University traffic managers. In this paper, the method of Resca1e Range Analysis (RRA) was used to estimate the Hurst Exponent Value (HEV) for the traffic inflow through the main entrance gate of a university as a control measure. Data from a university in the developing countries was collected and analysed. The number of vehicles that entered consecutively per five minutes was observed between 07:00 and 19:00 over a 144 count and 17 independent cases constructed between adjacent cases. Rescale Range Algorithm platform is then used for the data, and coded in FORTRAN Language. With a case made up of 128 consecutive five-minute dependent traffic inflow records, a total of 3348 vehicles entered the university community within the studied period while the average number of vehicles inflow per hour was 279. Average number of vehicles that entered per five minutes was 24. No vehicle entered between 13:25 and 13:30. For all cases, the estimated HEV range between 0.5742 and 0.6955. The computed average HEV was 0.6303, the coefficient of fitness (R2) for all cases range between 0.9552 and 0.9787, while the computed average value was 0.9680. The HEV greater than 0.5 estimated for all cases is an indication of positive con-elation called Persistent. It expresses the fact that there are extended periods in which the traffic inflow to the university community deviated from the long term mean. This information is useful for vehicle garage design. For reliable estimates of the average HEV for design purposes, the study period should be extended to a whole week or an academic session. "
The application of fractal box dimensions in predicting the emission characteristics of colliding sawdust particles for sustainable sawmilling
(CSIRO Publishing, 2012) Salau, T. A. O.; Oke, S. A.
"The prediction of emission characteristics of sawdust particles immediately after the cutting operation from the interaction of band saw's blade and plank is a growing research area. Still, a wide gap exists with respect to understanding the behaviour of sawdust particles as they collide with one another. Previous efforts have focused on non-collision states of sawdust particles. However, in real life, collision of particles must occur. With several particles colliding after the cutting operation. This paper establishes a new perspective of the fractal properties of sawdust particles in motion as a motivation to understanding how to control its toxicitv of effects on sawmill workers and maintain sustainable sawmilling activities. In particular, the possibility of predicting the fractal dimension of the randomly moving sawdust particles in sawmills that is generated as fractal curves using the combination of probabilities and theoretical fractal dimensions is investigated for the first time. Cases were established on the possible representations of the theory and practice. As an example, four cases were designed around varied number of fractal pattern combinations drawn out of five and fifty different probabilities combinations, ten different random number generating seed values and maximum of four fractal curves generation iterations as driven parameters. Preliminary study of the differences between theoretical fractal box dimension recorded a maximum absolute percentage error of 7.24% for fractal curve associated with fractal pattern five (i.e. Koch 5). In all the cases studied, average absolute percentage error decreases between 3.52 ± 1.18 and 1.51 ± 1.14 while the correlation coefficient (R2) decreases between 0.9315 and 0.7365 from case 1 to case 4, respectively. It is concluded that the model is a good predictor of sawdust particle emission at colliding states from cutting operation. This is reflected in the fact that the higher the number of fractal patterns (generators) in a study case, the smaller the correlation coefficient between average estimated fractal box dimension and predicted fractal dimension of the sawdust particles in motion in the sawmill. "
Application of average positive lyapunov in estimation of chaotic response peak excitation frequency of harmonically excited pendulum
(International Journal of Advances in Engineering and Technology, 2013-07) Salau, T. A. O.; Ajide, O. O.
"The fact that the drive parameters space of harmonically excited pendulum consist of mix parameters combination leading to different dynamics phenomena including chaotic and periodic responses is a strong motivation for this study aim at estimating the peak frequency that favour chaotic response. Simulation of pendulum and estimation of the average Lyapunov exponents by Grahm Schmidt Orthogonal rules at parameter nodal points selected from damp quality (2.0≤q≤ 4.0). excitation amplitude (0.9≤g ≤1.5) and drive frequency (0.5 ≤ ωD≤1.0) were effected using popular constant time step Runge-Kutta schemes (RK4, RK5 and RK5B) from two initial conditions through transient and steady periods. The impact of resolution on the measure of percentage of parameters combination leading to chaotic response (PPCLCR) was examined at resolution levels (RI to R5) for increasing drive frequency. The validation cases were from those reported by Gregory and Jerry (1990) for (ώᶹ,q,g≡ 2/3,4,1.5) and (ωυq,g≡ 2/3,4,1.5) simulated from (0. 0) initial conditions. Corresponding validation results compare well with reported results of Gregory and Jerry (1990). The estimated peak frequency (0.6 radian /s) is the same across studied resolutions initial conditions and Runge-Kutta schemes. The peak value of PPCLCR is 69.5. 69.4 and 69.4 respectively for RK4. RK5 and RK5B at initial conditions (0. 0). When initial conditions is (I. 0) the corresponding PPCLR value changes in significantly to 69.6. 69.7 and 69.6 for RK4, RK5 and RK5B. Therefore affirms the utility and reliability of Lyapunov exponent as chaotic response identification tool. "
The application of duffing's equation in predicting the emission characteristics of sawdust particles
(2010-09) Salau, T. A. O.; Oke, S. A.
"Sawdust particles soon after emission from the cutting machine usually move dynamically with transformation in some dimensions. This paper models the sawdust particle motion as a two dimensional transformation system of continuous time series. Cost could be saved using this approach instead of utilizing dynamic systems that depend on time history Two dimensional graphical representation of continuous time series of Duffing's dynamic system for sawdust particles was investigated with emphasis placed on application to sawdust particle motion and the saw machines. Pr~liminary studies were made using the harmonic functions, F(t) = Cos(wt) and F(t) = Sin(wt), for their familiarity in both science and technology communities. The solution to Duffing's model equation for the sawdust particles was sought from displacement and velocity perspectives, using the Runge-Kutta Algorithm. Linear transformation that guarantees non-negative values of time series was implemented. This was followed by the respective computation of the x- and y-components of the resulting time series values of the sawdust movement using a 21tmodulated time measured in radians. The graphical representations of the x- and y-components compared well quantitatively and qualitatively with the corresponding phase plots. The feasibility of modelling sawdust dynamics as emission from band saws was therefore demonstrated here, in approaches that thus advance knowledge of sawdust emission studies. "
Application of neurofuzzy in the develoment of road bump designs
(2007-05) Oke, S. A.; Johnson, A. O,; Salau, T. A. O.; Adeyefa, A. O.
"This contribution is on the development of a neurofuzzy model that aids in capturing imprecision and uncertainty in the. various road bump parameters. Road bumps are structures built on roads to act as obstructions to vehicles plying these roads. The neurofuzzy methodology is used to check the vehicle speeds to acceptable standards. Particular use is made of neurofuzzy since it is an improvement on the traditional model proposed earlier in the literature. The work is motivated by the need for a more reliable and easily understandable methodology that guides decision makers in making correct decisions in a timely manner The results obtained demonstrate that it is feasible to apply the model in practice. The paper is new in that it proposes a novel approach to quantifying the results of road bump design in order to achieve worthy and reliable result. "
Artificial Neural Network Modeling for Al-Zn-Sn sacrificial anode protection of low carbon steel in saline media
(2012) Oluwole, O.; Idusuyi, N.
This work presents the artificial neural network(ANN) modeling for sacrificial anode cathodic protection of low carbon steel using Al-Zn-Sn alloys anodes in saline media. Corrosion experiments were used to obtain data for developing a neural network model. The Feed forward Levenberg-Marquadt training algorithm with passive time, pH, conductivity,% metallic composition used in the input layer and the corrosion potential measured against a silver/silver chloride(Ag/AgCl) reference electrode used as the target or output variable. The modeling results obtained show that the network with 4 neurons in the input layer, 10 neurons in the hidden layer and 1 neuron in the output layer had a high correlation coefficient (R-value) of 0.850602 for the test data, and a low mean square error (MSE) of 0.0261294. 9
Assessment of household energy efficiency in Ibadan, Nigeria
(2012) Adediran, A. A.; Simolowo, O. E.
Household require significant amount of energy to meet various services like lighting, cooling, heating, cooking, refrigeration, electronic entertainment, e.t.c. There’s virtually any household activity that can be carried out without the use energy. The requirement for household energy in Nigeria has been growing over time. There are various energy sources available to households in the country. They include fuel, wood, charcoal, sawdust, gas, petrol, kerosene and electricity. It is fairly settled from literatures that electricity is the cheapest and cleanest energy source available. However, Nigeria, with a population of over 150 million people only has about 40% of its population having access to electricity with most of the people with access living in the urban centers (UNDP, 2011). Access to electricity in Nigeria is the dividing line between the urban areas and the rural areas. It can be said that Nigeria is suffering from “ Energy Poverty”. For a nation that seeks to attain the status of developed economy, the issue of energy poverty must be resolved fast.
Assessment of large-scale motion in turbulent boundary layer subjected to a short roughness strip
(Begell House, Inc, 2011) Oyewola, M. O; Ismail, O. S.; Adaramola, M. S.
Measurements have been made in a turbulent boundary layer which is subjected to a short roughness strip, with the view to examine the influence of short roughness strip on the large scale motion. This is quantified through the analysis of autocorrelation of the fluctuating velocities in the streamwise and wall-normal downstream of a roughness strip. Also, distributions of cross correlation functions are presented. The results indicate that, reference to the smooth wall, there are noticeable changes in the distributions of autocorrelation and cross correlation functions, suggesting that the large scale motion is altered as a result of the modification of the structure near the wall in the presence of the roughness element. This change extends to significant portion of the boundary layer.
Bridging Nigeria energy gap by utilizing her coal
(2017) Towoju, O. A.; Petinrin, M. O.
Many nations who meet their energy generation requirements are one way or the other tapping from the vast resources which is inherent in coal. A wide gap exists between the energy requirement of the Nigerian populace and the generated amount. This can be bridged by the utilization of its vast amount of bituminous coal in her reserves, with favourable properties of low percentage moisture and ash which is an advantage in terms of handling costs, ease of transportation and better overall system efficiency. The percentage moisture value for the analyzed sample was 5.0 percent while the percentage ash value was 6.6 percent. Both determined values are relatively low when compared to results of the analysis reported for some other countries coal.
Briquetting of wood and agricultural wastes for energy production
(2005) Igbeka, J. C.|; Popoola, L.; Ajayi, S. S.; Onilude, M. A.; Olorunisola, O. A.; Raji, A. G.; Afrifa, E. S. D.; Fadare, D. A.
CAD/CAM applications: status and impact in Nigerian industrial sector
(2010-06) Simolowo, O. E.; Okonkwo, F. C.; Kehinde, O. O.
This research assessed, among others, the current status and the impact of Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) applications in the Nigerian industrial and technological sector. Two prominent cities Lagos and Ibadan were selected as centers of case studies to establish the level of the applications. Data was collected from industries within the 2 cities in the areas of manufacturing, design, production, construction and consultancy service units during a yearlong study. From the survey, 56% of companies visited in Lagos metropolis apply Computer-Aided Engineering (CAE) activities in their operations. Also 60% of the companies considered in Ibadan metropolis apply CAE, of which 75% are into CAD, 12.5% are applying CAM whereas 12.5% are utilizing Computer Numerically Controlled (CNC) machines. Conclusively, the commonest CAD techniques employed by the industries surveyed are Auto CAD and Archi CAD representing 55.6% and 33.3% of the total packages being used in the visited companies respectively.
Ceramic engines: material properties for higher performance
(1998) Simolowo, O. E.
The four-stroke reciprocating internal combustion engine has been used as a case study, being that commonly utilized in most automobiles. General properties of ceramics were discussed while exposure was given to some high-performance ceramics. Theoretical deduction and analysis were then carried out to show improved engine performance using ceramic component. the engine performance parameter considered are:(i)power output (ii) mean effective pressure(iii) speed of engine rotation and (iv) mechanical efficiency. analysis based on ceramic properties showed that ceramics such as silicon carbide (SiC), silicon nitride(Si3N4), zirconia (ZrO2) and , titanium oxide (TiO2) proved to have more favourable properties for most engine parts when subjected to engine conditions where they are located as compared to their metallic, steel and alloy counterparts. Though much work has been done in the production of ceramic engines, predictions as to developing (i) adiabatic ceremic engines and (ii) turbo compounded engine show the extent to work that still needs to be done in this area of developing ceramic engines.