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Item HEAT TRANSFER IN COOLED AERO-DERIVATIVE TURBINE BLADE: A NUMERICAL ANALYSIS(Journal of NIMechE, 2019-03-15) Orah, A. .M.; Nasir, .A.; Hassan, .A. B.; Bori IgeAero-derivative gas turbines have found extensive applications as mechanical drives and in medium-sized utility power plants. It has a higher efficiency due to its high pressure and temperature operations; hence, the need for proper cooling techniques to achieve the required creep life and attain reliability. In this paper, the heat transfer in a cooled aero-derivative gas turbine blade is determined numerically using the Alternating Direction Implicit (ADI) scheme of Computational Fluid Dynamics. The convective heat transfer coefficient of the governing Newton’s law of cooling equation is the basis. A solver was developed for the heat transfer problem based on the selected boundary conditions and designed cooling parameters of the GE PGT25+ aero-derivative gas turbine to obtain the temperature distribution within a cooled blade for 30 minutes in-service operation. There is no significant change in the temperature profiles across the nodal points, varying between 90oC – 600oC. The temperatures within the blade are significantly constant throughout the operating time of the turbine blade, inferring that there was effective heat transfer from the blades to the cooling air since the temperature variation did not exceed the melting point of the blade material. The ADI strategy is, therefore, suitable for heat transfer design computations for complex systems like the gas turbine engine.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.Item IMPROVEMENT OF HEAT DISSIPATION RATE OF AN AUTOMOBILE BRAKE DRUM USING FINS INCORPORATION(Bartin University, Turkey, 2018-12-31) Bako, .S.; Bori Ige; Musa, .N.; Nasir, .A.The concept of incorporation of fins in automobile brake drum came up as a measure to subdue or address the thermal problems associated with it, which ultimately leads to brake failure. In order not to compromise the original weight of brake drum,1/10th of the overall wall thickness of the brake drum was converted into fins on the outer surface of the brake drum for effective heat dissipation. Modeling and simulation analysis were carried out using Solidworks (2013) software, on both the existing and modified brake drum, followed by validation using theoretical finite element analysis. The minimum temperatures observed from the simulation analysis were 4935K and 4927K for the existing and the modified brake drum model respectively. While maximum von Mises stress were 22, 378.9 N/M2 and 21, 971.2 N/M2 and the maximum displacements were 5142 x 10(-5)and 5102 x 10(-5) for the existing and the modified brake drum model respectively. This implied that the modified brake drum have improved strength and better heat dissipation rate than the existing model.Item Investigation of Fracture behaviour of API X70 Pipeline Steel(IOP Publishing Ltd, 2021) M.S. Egene,; O. Adedipe,; U.G. Okoro,; Obanimomo, K.T.Oil and gas production has significantly increased over the years in order to meet future demands for oil and gas products, regardless of the unstable price being experienced by producing nations. The use of pipelines for the transportation of these products has been the globally recognized solution. These pipelines are fabricated by welding and their fracture properties depend on a number of factors which include temperature, particularly for pipelines operating in cold environment such as deeper water depths. Therefore, information of fracture behaviour of welded pipelines located in cold regions is therefore important for reliable design for service. In this paper, fracture behaviour of welded x70 pipeline steel was investigated using charpy v-notch specimens. Impact tests were carried out on weld and parent materials at temperatures -10°C, -20°C, -40°C, -60°C, -80°C, -100°C, -120°C, -160°C, 0°C, 10°C and 20°C. Results revealed that higher energy was absorbed in the weld than in parent materials regardless of the test temperature used. results implied that the fracture behaviour of the material could be significantly influenced by temperature, welding and the notch sensitivity of the materials.