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Item Pedestrian-level Air Flow and Ventilation around Adjacent Buildings in Step-up Configuration(Nigeria Journal of Engineering and Applied Sciences (NJEAS), FUT Minna, 2017-08-24) Ayo, .S. A.; Mohd-Ghazali, .N.; Bori IgeThe outdoor air ventilation impact of a taller building at a downwind location in a layout of two adjacent buildings in different step-up configurations is presented in this paper. The criteria for ventilation assessment adopted are dimensionless parameters called velocity ratio (VR) and air ventilation rate (AER), and the parameters examined are the separation distance (WV) between the buildings and the ratio of height of downwind building to that of upwind building, herein referred to as building height ratio (HR). A three-dimensional (3-D) numerical simulation employing the Computational Fluid Dynamics (CFD) technique based on Reynolds-Averaged Navier-Stokes (RANS) equation and Realizable k-ε turbulence model was used to study the turbulent flow field around various full-scale size configurations of the adjacent buildings. Results show that while VR generally increases with height ratio, it increases with separation distance until a certain maximum distance which depends on the height ratio. AER on the other hand generally increases with height ratio, but decreases with separation distance. The results indicate that greater air motion is induced at the pedestrian level as the height of the downwind building increases, and greater rate of air flow is exchanged between the buildings cavity and the surroundings. Based on the VR results obtained for the building configurations examined, a separation distance of between 18 m and 30 m is proposed for configurations 2.0 ≤HR≤ 3.0, and between 18 m and 24 m for configurations HR = 1.0 and 1.5, to maximally invigorate the pedestrian-level air flow.Item Enhancing the Cavitation Erosion Resistance of 304 Stainless Steel by Laser Surface Alloying with Molybdenum(Nigeria Journal of Engineering and Applied Sciences (NJEAS), FUT Minna, 2017-08-24) Bori Ige; Muriana, .R. A.; Man, .H. C.; Okegbile, .O. J.; Ayo, .S. A.; Babawuya, .A.Type 304 stainless steel is the most versatile and widely used austenitic stainless steel, it accounts for more than 50% of all stainless steel produced. It is commonly used in liquidhandling equipment, house hold utensils and lot of applications in almost every industry. However, poor surface properties in terms of wear resistance, due to its low hardness made it susceptible to cavitation erosion, which is a usual mode of degradation of engineering parts in contact with fast-flowing or vibrating liquids. This work is an attempt to improve the cavitation erosion resistance of 304 stainless steel by laser surface alloying with Molybdenum (Mo). This was made possible by using a 2kW continuous wave Nd-YAG laser. The alloying powder was placed in advance on the surface of the substrate by pasting to a thickness of 0.1mm, followed by laser beam scanning at an optimal speed of 20 mm/s and 30 mm/s (each at a beam diameter of 3mm) and a laser power of 1.2kW, in order to achieve surface alloying and modified surfaces were obtained by 50% overlapping of adjacent tracks. The microstructure and composition of modified layer were also studied for more insights. Ultrasonic induced vibrator tester was used to carry out cavitation erosion test. Cavitation erosion resistance (Re) was observed to have increased with the Mo content in the alloyed layer, the Re of the specimens modified with Mo was improved by a factor of 1.4 (for v = 20 mm/s) and 1.5 (for v = 30 mm/s), when compared with that of the as-received 304 stainless steel substrates.Item DESIGN AND CONSTRUCTION OF A SMALL SOLAR POWERED AIR BLOWER FOR CHARCOAL FIRED FURNACE(JOURNAL OF THE NIGERIAN INSTITUTION OF MECHANICAL ENGINEERS, 2019-09-30) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgeIn Nigeria almost all the local foundry shops rely on the manually operated blowers for supplying air for the combustion of the charcoals to melt metals. This manually operated blower has showed that much man-hour is required during firing as one laborer is dedicated to driving the rotary blower. This is labourous and reduces the rate of productivity of the enterprise. Therefore, it is necessary to find easier ways of supplying the energy required for the combustion so as to increase productivity. A solar powered blower is designed and constructed in this work. The performances of manually operated and solar powered air blowers are compared. Performance results of the manually operated air blower showed that it takes about 67 minutes and 42 minutes to melt 4kg of aluminum and zinc respectively. On the other hand, for the solar-powered air blower, it takes about 30 minutes and 17 minutes to melt 4kg of aluminum and zinc respectively. This indicates that the solar-powered air blower takes a shorter time to melt metals when compared with the manually operated air blower. In addition, the solar powered air blower eliminates the laborious aspect of supplying energy for melting metals and also reduces the times spent in metal melting process.Item INVESTIGATION OF PRESSURE TRANSIENTS AND WAVE PROPAGATION EFFECTS IN A PRESSURIZED PETROLEUM PIPELINE USING WANDA TRANSIENT SOFTWARE(Nigeria Journal of Engineering Science and Technology Research (FUT Yola), 2019-05-04) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgePressure transients and effects of wave propagations due to instantaneous valve closure in a pipeline transporting premium motor spirit (PMS) were investigated using simulation approach in this paper. Pressure transient investigation and analysis are often more significant than the steady state analysis that hydraulic Engineers usually use in pipeline design because almost all pipelines experience pressure transient in their operations. Pressure transient analysis helps to understand the additional loads a pipeline can be subjected to as a result of instantaneous valve closures. In this paper, WANDA Transient 4.5.1210 commercial software was used for the analysis of the pressure transients due to instant valve closure in a petroleum pipeline. Three different instantaneous valve closure times of 4.5, 9 and 18 seconds were used in this investigation. It was observed in this research that rise in pressure is highest (1304 kPa) at node F (the node where the valve closure takes place) against the inlet pressure of 120 kPa and also there is drastic drop in pressure (-53.7 kPa) at node B (a node just upstream end of the pump). Also cavitations were observed at Node B due to the development of negative pressure as a result of the valve closure. The research recommends that surge tank should be installed at node F to stabilize the pressure surge and also air vessels are to be installed at node B to curtail damages due to cavitations.Item Hydraulic Transient Analysis in Fluid Pipeline: A Review(JOURNAL OF SCIENCE TECHNOLOGY AND EDUCATION , ATBU, BAUCHI, 2019-12-19) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgeHydraulic transient is an important phenomenon in the pipeline transportation system that have adverse and catastrophic effects on the most susceptible pipeline components such as valve, pumps, pipes as well as the environment. The major causes of hydraulic transients are sudden or abrupt valve closure or pump failures as a result of power outage. The major challenges of transient analysis techniques are to optimally achieve a balance between accuracy of results obtained from the analysis and simplicity of the adopted techniques in analyzing both complex and simple pipeline networks. In order to attain this fit many researchers have proposed, developed and used different models and algorithms to this regards. This paper surveys various transient analysis techniques, model and algorithm for protection of pipeline network system with a view of achieving optimal trade-off between transient analysis techniques used and the type of fluid flow pipeline analyzed. Performance and limitations of some of the previous works are identified. Finally, future investigations on petroleum and its products were recommended.Item Hydraulic Transient Analysis of a Petroleum Pipeline Transporting Dual Purpose Kerosene Using Modelling and Simulation Approach(Premier Journal of Engineering and Applied Sciences, 2020-04-21) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgeHydraulic transient analysis of a pipeline transporting dual purpose kerosene (DPK) was carried out in this research using simulation approach. Many petroleum pump stations and pipelines experience leakages and failures at their nodes due to changes in flow parameters that lead to hydraulic transient. Such types of unsteady situations are encountered frequently in pipelines where the valves are suddenly closed. WANDA Transient 4.5.1210 commercial software was used for the analysis of hydraulic transient. Variation in pressures and discharges with respect to time after the closure of a gate valve at the downstream of a pipeline were observed. It was observed in the study that pressure at node F rise significantly up to about 1354 kPa against the initial inlet pressure of 120 kPa due to the instantaneous valve closure and it was also observed that pressure at node B drops to a negative pressure of -101 kPa and hence the formation of cavitations at that node B and pipe P2. The analysis showed that the magnitude of the pressure surge decreases as the valve closure is increased. The research recommended that surge tanks should be installed at node F to stabilize the pressure surge and also air vessels are to be installed at nodes B to curtail damages due to cavitations.Item Investigation of the Effects of Hydraulic Transient due to Instantaneous Valve Closure in a Petroleum Pipeline(NIPES Journal of Science and Technology Research, 2020-06-01) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgePressure surge analysis of petroleum pipeline transporting automotive gas oil (AGO) also known as Diesel oil was carried out in this research work. Pressure transient analysis is often more significant than the steady state analysis that engineers usually use in pipeline design. Pressure transient analysis helps to understand the additional pressures the pipeline can be subjected to as a result of instantaneous rapid valve closures or pump failure. The fluid pressure and flow rate in the pipeline system may change significantly at some intervals of time due to the valve closure and such types of unsteady situations are encountered more often in pipelines where the valves are suddenly closed. In this paper, pressure surge due to instantaneous valve closure in a petroleum pipeline conveying AGO was studied in a virtual environment. WANDA Transient 4.5.1210 commercial software was used for the analysis of the pressure surge in the pipeline due to instantaneous valve closure time of 4.75s. It was observed in the study that pressure at some nodes rise significantly up to about 1400 kPa against the initial inlet pressure of 120 kPa due to the instantaneous valve closure and it drastically drops at some nodes to negative pressure of about -100 kPa and hence the formation of cavitations. The analysis showed that the magnitude of the pressure surge decreases as the valve closure is increased.Item Techno-Economic Analysis of Combined Cycle Power Plants for Electricity Generation in Nigeria(Nigerian Journal of Technology (NIJOTECH), University of Nigeria, Nnsuka, 2022-09-10) Bori Ige; Orah, .A. M.; Ayo, .S. A.This paper presents a techno-economic approach to readily assess the profitability or otherwise of combined cycle power plants (CCPPs) for increased electricity production in Nigeria. As a case study for this analysis, a combined cycle gas turbine plant with 650MW installed capacity at Afam VI power station is used to evaluate the installation of a 1000MW and 1500MW CCPP economically. The results and analysis determined a Levelized cost of electricity of N41.57k/KWh and N34.09k/KWh for the 1500MW and 1000MW CCPP, respectively. It signifies an increase of 33.33% and 66.67% in the cost of electricity per kWh between the 1000MW and 1500MW plant capacities respectively, relative to the 650MW CCPP. Therefore, the low LCOE makes it economically viable to install the 1000MW CCPP for electricity production in the country. The paper also proposes upgrading existing gas-fired power plants in the country into combined cycle power plants for improved electricity supply.Item Investigation of the Temperature Variations in Aeroderivative Gas Turbine Blade Cooling(Journal of Materials Engineering, Structures and Computation, 2023-11-22) Orah, A. .M.; Nasir, .A.; Hassan, .A.B.; Bori Ige; Ayo, .S. A.In order to improve performance and efficiency, modern-day gas turbines operate at high temperatures. It is essential to use suitable cooling techniques on the blade and other hot areas since the elevated temperatures might exceed the metal melting temperature of the turbine blades. This paper presents the numerical modelling of heat exchange in a cooled aerodrivative gas turbine blade depending on the Newton’s law of cooling equation as governing equation, then integrating the heat transfer coefficient by convection into the alternating direction implicit (ADI) approach of computational fluid dynamics (CFD). Based on the chosen boundary conditions and the gas turbine's intended cooling characteristics, a model for the heat transfer problem was created. A MATLAB code was developed to ascertain the temperature variations inside a cooling blade for a half-hour in-service operation. This study found a temperature difference between the transient and final temperature values of roughly 25 to 300oC, demonstrating the heat transfer process between the hot gases and the coolant air. It inferred effective heat transmission from the blades to the cooling air because the temperature differential within the blades did not rise over the melting point of the blade material and it yielded an average blade temperature of 400°C. Thus, the ADI technique is appropriate for heat transfer design calculations for intricate devices such as the gas turbine engine.