Mechanical Engineering

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Mechanical Engineering

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Author: search.filters.author.Nasir, .A.

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    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.
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    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.
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    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.