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Item Delaying transition in a Blasius boundary layer with finite compliant panels(Fourth International Symposium on Bifurcations and Instabilities in Fluid Dynamics (BIFD),, 2011-07-18) Bori Ige; Zhao, .X.; Yeo, .K. S.Compliant surfaces have been shown to be a promising passive control measure for controlling and delaying boundary layer transition in various theoretical studies [1-2]. In this paper, we report on a recent study we have done on the evolution of pulse-initiated disturbance wavepackets over one or more finite-length compliant panels. The broadband nature of a wavepacket offers a central advantage in permitting natural selection of most dominant waves to operate through the sum of its growth processes. This may be helpful in identifying the critical waves and key processes that are involved at the various stages in natural transition. The initiation, evolution and final breakdown of wavepackets into the incipient turbulent spots in a Blasius boundary layer was modelled by Direct Numerical Simulation (DNS) briefly described in [3]. The comparative evolution and transition performance of three cases are discussed here, namely the rigid-wall case, a single-panel wall and a two-panel wall. In all cases, a fixed vertical-directed delta pulse of small amplitude was initiated at the point x / 349.4, where 2.3182103m is the displacement thickness of the boundary layer at the initiation point. The evolution and breakdown of the wavepacket in a Blasius boundary layer on a rigid wall has already been reported in [3]. For the single-panel case, a finite section of the wall from x / 450 to 762 was replaced by a tensioned membrane on a viscoelastic foundation, whose properties were designed to inhibit the development of compliant-wall modes. The simulation results showed that, the upstream intervention by the finite compliant panel effectively delayed the onset of the incipient turbulent spot by a distance of about 100 cm ( x / 430). This represents an approximately 30% increase in the transition distance measured from the point of wavepacket initiation. Spectral study indicated that the relatively short membrane panel was able to effectively attenuate the primary 2-D Tollmien-Schlichting (TS) wave mode so that resultant wavepacket after the panel was dominated by a pair of oblique waves. Subharmonic secondary instabilities [4-5], which are responsible for nonlinear disturbance wave amplification on a rigid wall, were thus inhibited by the absence or near absence of the 2-D TS wave mode. Staggered Λ-structures and streamwise streaky structures similar to those found in the rigid wall case were observed for the single-panel case, but much further downstream. A second tensioned membrane panel of the same length was added at x / 1359-1658 to form the two-panel case. The last stage of the present simulation shows the wavepacket arriving the location x / 2000 in a perfectly laminar form ( max | u | /U 0.05 ) – this already represents an increase in transition distance of about 50% over the corresponding rigid-wall case. The eventual breakdown location will be further downstream as the wavepacket has not displayed the usual structural features that signify imminent breakdown. This study has shown the efficacy of short compliant panel(s) in controlling and delaying transition.Item Evolution of wavepacket over short compliant panels in a Blasius boundary layer(American Physical Society (APS), 65th Annual Meeting Division of Fluid Dynamics (DFD), 2012-11-18) Bori Ige; Yeo, .K. S.; Dou, .H-S.Compliant surface has been proved in various theoretical studies as a promising tool in delaying transition. This study concerns our recent work carried on the evolution of pulse-initiated disturbance wavepackets over finite-length compliant panels in a Blasius boundary layer by direct numerical simulation (DNS) method. A finite section of the wall was replaced by a tensioned membrane on a damped foundation. By comparing with the rigid wall case, the upstream intervention by a finite compliant panel was found to effectively delay the onset of the incipient turbulent spot – an increase of about 40% in the transition distance with respect to the initiation point was obtained. Transition distance to the occurrence of the incipient turbulent spot was increased further to about 75% relative to a rigid wall when a second compliant panel was introduced. Spectral analysis shows the important role of the fundamental 2D modes in wavepacket evolution and the roles played by compliant panels in transition delay.Item DEVELOPMENT OF A BRAKE DRUM MODEL WITH FINS INCORPORATION FOR HEAT DISSIPATION ENHANCEMENT(5th Multi-disciplinary academic conference, Ahmadu Bello University, Zaria. January 11, 2018. Pp. 190 – 205., 2018-01-11) Bako, .S.; Bori IgeExtreme heat within an automobile brake drum could cause brake failure which could as well lead to death of passengers and lost of properties. One of the ways to dissipate heat faster from an automobile brake drum is by incorporating fin on the outer surface of the brake drum as pointed out in many literatures. This work concerns converting 1/10 0f the overall height thickness of the brake drum into fins for effective heat dissipation by both conduction and convection. During the modified brake drum development process, necessary fin design formulae were taken into account. Modeling and simulation analysis were carried out using Solidworks (2013) software, followed by validation using theoretical Finite Element analysis. The minimum temperatures obtained from the simulation analysis were 4935K and 4927K for the existing and the modified brake drum model respectively. While maximum displacements obtained from the simulation analysis were 5142×10−5𝑚𝑚 and 5102×10−5𝑚𝑚 for the existing and the modified brake drum model respectively. This implies that the modified brake drum have improved strength and better heat dissipation than the existing model. This is as the result of the circumferential arrangement of the fins on the outer surface of the brake drum.Item Modelling of the Temperature Distribution in a Cooled Aeroderivative Gas Turbine Blade with Cooling Holes(2021 Sustainable Engineering and Industrial Technology Conference, Faculty of Engineering, University of Nigeria, Nsukka, Enugu State, 22nd -25th June, 2021. Pp. 171- 176., 2021-06-22) Mohammed, .O.; Nasir, .A.; Bori Ige; Hassan, .B.Aero-derivative gas turbines have found extensive applications, as mechanical drives and medium sized utility power plants on o shore platforms and in petrochemical industries; because of its high operating temperature and pressure, it has a higher e ciency. The high operating conditions of the engine makes it necessary to adopt e ective cooling techniques to achieve the required creep life and attain reliability. This makes the study of the heat transfer within the gas turbine blade essential. This study models the temperature distribution in a cooled aero-derivative gas turbine blade. A numerical model was developed from the interpolation of the Newton’s law of cooling equation and the Alternating Direction Implicit (ADI) scheme. A MATLAB solver was generated for the heat transfer problem based on the selected boundary conditions and designed cooling parameters of model engine: GE PGT25+ aero-derivative gas turbine. It was found that there was e ective heat transfer from the blades to the cooling air with a cooling e ectiveness of 0.5, and the temperature gradient within the blade was within safe operating limits not exceeding the melting point of the blade material. It was deduced that the ADI strategy accurately compute temperature distributions within the blade, in time and space, thereby making it suitable for heat transfer design computations for complex thermodynamic systems like the gas turbine engine.Item Modelling of Thermo-mechanical Fatigue in an Aeroderivative Gas Turbine Blade made of Inconel 738LC(Faculty of Engineering, University of Nigeria, Nsukka, Enugu State, 2021-06-22) Orah, .M.; Nasir, .A.; Bori Ige; Hassan, .B.The hot gas section of the gas turbine engine, especially the blades, are usually subjected to high thermal and mechanical loading, as a result su er thermo-mechanical fatigue. The design process usually involves appropriate selection of the turbine blade materials, it is therefore necessary to carry out thermo-mechanical fatigue studies on gas turbine blades to predict blade life. This study models the thermo-mechanical fatigue on gas turbine blade made of nickel based super alloy IN738LC. Simulink was used to develop thermal models to compute the heat transfer coe cient on the cold and hot sides of the blade, and a stress model to compute the centrifugal tensile stress. The heat transfer coe cients, Reynold’s number, and Stanton number at di erent velocities on the hot and cold section of the blade was obtained. The relationships between the Heat transfer coe cient and the Reynold’s number with the change in velocities at the hot and cold sections of the blade was also established. The stress model computed the centrifugal tensile stress acting on the blade at 31.41GPa.The heat transfer and stress models are therefore necessary for TMF calculations to predict the creep life of the blade to prevent engine failure.Item Delaying transition further with the aid of a short compliant panel in a Blasius boundary layer flow(The Chinese Society of Theoretical and Applied Mechanics (CSTAM), Fluid Mechanics Division Conference, Guilin, China., 2012-11-12) Bori Ige; Yeo, .K. S.; Dou, .H-S.; Zhao, .X.The cost of fuelling especially for those in the transport industries could be reduced drastically if there is a means of reducing drag force over their vehicles while in motion. One way to overcome this is to use compliant (membrane) surface; a passive control means which has been proved in various theoretical studies as a promising tool in delaying transition further. In this paper, following the earlier work done on flow over rigid wall within a Blasius boundary layer, we account for the current study carried out on the evolution of pulse-initiated disturbance wavepackets over a finite-length compliant panel by direct numerical simulation (DNS) method. For the single-panel case, a finite section of the wall from X = x/δ0 = 450 -762, was replaced by a tensioned membrane on a viscoelastic foundation, whose properties were designed to inhibit the development of compliant-wall modes. Where δ0 is the displacement thickness at the perturbation location. A small amplitude vertical initiating delta pulse was introduced from the wall streamwise location X0 = 349.4 (x0 = 81cm), and study in detail both spatially and spectrally how the wavepackets generated evolve from the initiating point to the breakdown location over a Blasius boundary layer. The simulation results showed that, the upstream intervention by the finite compliant panel effectively delayed the onset of the incipient turbulent spot by a further distance of Δx = 550, when compared with the rigid wall case results that earlier broke down at X = 1420. This represents an approximately 51% increase in the transition distance measured from the point of wavepacket initiation. Spectral study indicated that the relatively short compliant panel was able to effectively weaken the primary 2-D Tollmien-Schlichting (TS) wave mode, thereby extending the linear regime, so that resultant wavepacket after the panel is dominated by two oblique wave modes and this is the effective strategy of transition delay.Item Development of Screw-Type Briquetting Machine for Municipal Solid Waste(2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria, 2017-10-17) Okegbile, .O. J.; Bori Ige; Danlami, .S. M.The Hydra headed problem of deforestation and Municipal Solid Waste (MSW) Management has bedeviled Nigerian States. Deforestation has put Nigeria on the world’s map as the highest contributor to the world’s deforestation of its primary forest (contributing over 50%), as over 70% of its population depends on firewood and charcoal for cooking and heating. The rising profile of MSW, characterized by inefficient management methods make most Nigerian cities an eye sore, with uncollected waste littering almost every available space, drainages and water channels which poses great danger to human existence. Without alternative energy source available to the growing population, deforestation will continue unabated and in the nearest future Nigeria risk losing all of its forest resource. A Screw-Type briquetting machine was developed that utilizes crushed, combustible MSW to form briquettes to be used for cooking and heating, which is using one problem to fix another. MSW was formulated, crushed and used to form briquette. The briquettes produced burn in similar way to charcoal when compared. This will reduce to the barest minimum, deforestation rate and improve the management of MSW by utilizing as a resource what is termed waste. The developed machine has a throughput capacity of 2605.4Kg/hr and is driven by a 5 Horsepower (5 hp) electric motor.Item An Investigation On Ventilation and Air Conditioning (VAC) Installation, Design and Performances of Selected Buildings in Ilorin, Kwara State, Nigeria(2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria, 2017-10-17) Yusuf, .A. W.; Bori Ige; Nasir, .A.time. Heating, ventilation and air-conditioning (HVAC) play an important role in providing a comfortable condition for occupants in a building. This work concerns air conditioning designs, installations, and performances of some event centres namely: Banquet Hall, Atlantic Event Centre and Nimatoni Event Centre and some offices within the Kwara State Ministry of Water Resources. The impact of the effect of improper design and ventilation on energy efficiency and consumption were also considered. The event centres and offices were studied, by taking both the temperature and relative humidity values for over a period ranging from 75 minutes to 130 minutes, with the use of a device referred to as HOBOware temperature/relative humidity data logger coupled with a HOBOware Software interface installed on a personal computer, for post processing of acquired data. The obtained results of the event centres showed variations in the capacities of the installed air-condition understudied. Also from the results obtained, the cubic meter per minute (cmm) values were found to be 0.0896, 0.2908 and 0.0404 for Banquet hall, Atlantic Event Centre and Nimatoni Event Centre respectively, and these were below the standard recommended value of 0.4245 in the literature.Item Formation of Ceiling Boards by the Combination of Sugarcane Bagasse and Rice Husk(International conference on global & emerging trends, Baze University, Abuja, Nigeria. 2 - 4 May, 2018. Pp. 140 – 143., 2018-05-02) Jesuloluwa, .S. I.; Bori IgeConstructing housing components from agricultural wastes have become a special area of research in engineering. Hence a lot of resources is pushed into this to obtain sustainable, eco-friendly and low-cost houses. This work studies some properties of ceiling boards produced from sugarcane bagasse and rice husk. The ceiling boards were produced using water, cement as binder with binder composite ratio of 3:2 by weight, sugarcane bagasse and rice husk of varying ratios by weight from 100% of bagasse to 0% of it with a 25% decrease. The compression of the boards was done manually using moulded block as weight. From the results, it was observed that the ceiling board produced with 100% sugarcane bagasse has better properties to be considered for ceiling board as compared with the most commonly used ceiling boards like Plaster of Paris(POP), asbestos and Poly Vinyl Chloride(PVC). The properties examined are thermal conductivity, thermal resistivity, water absorption and density. The better ceiling board has thermal conductivity to be 2.27W/mK, thermal resistivity of 0.441 mK/W, water absorption of 16.89 and density of 470.3 kg/m3.Item Development of Footstep Electricity Energy Generating Machine using Dual Generator(Alex Ekwueme Federal University, Ndufu-Alike Ikwo, Ebonyi State, Nigeria, 2019-05-15) Igbo, .E. B.; Bori IgeFootstep electricity energy generation machine have been seen in most populated country and the different existing machines have various capacity of generated electricity power. The concept and the technology is simply the production of electrical energy by weight which acts on the footsteps. Footstep electrical energy generation is of three types namely; rack and pinion, piezoelectric method, fuel and piston method. It was comparatively discovered that the rack and pinion mechanism is more effective, efficient with less cost of operation and maintenance. In the existing rack and pinion method, energy was not adequately harvested from footsteps as a result of many gears, shafts and incorporation of a single generator. This takes time to generate electricity and the output capacity is low in watt. With this motivation, a prototype footstep electricity energy generating machine using dual generators, chains and sprockets was developed. This was designed by considering parameters such as human weights, speed and low cost. The prototype was designed to be a value for money production in the power generation sectors. For designing the work rack and pinion, human weight were studies to understand the operation. At the end, the machine was fabricated using local material. The machine upon fabrication was evaluated at ten (10) different human weights of 40, 50, 53, 56, 60, 70, 85, 101, 105, 108 kgs and power of 6.69, 6.949, 3.92, 10.848, 8.29, 8.339, 12. 064, 11.349, 11. 359 and 11.359 watts, with angular speeds of 5.08, 5.28, 2.98, 8.24, 6.30, 6.33, 9.16, 8.62, 8.63, 9.35 rpm were obtained respectively. The result showed that weight is directly proportional to both power and angular speed. The result showed that optimism occurred at 85kg. Using a dual generators increase higher electricity energy generation, effective and efficient harvesting of footstep energy.