Work place: The Federal University of Technology, P.M.B. 704 Akure, Nigeria
E-mail: oadahunsi@futa.edu.ng
Website:
Research Interests:
Biography
DAHUNSI Olurotimi Akintunde is a professor at the Department of Mechanical Engineering, Federal University of Technology, Akure, Nigeria. He obtained B.Eng. and M.Eng. Degrees in Mechanical Engineering from the Federal University of Technology, Akure Nigeria, and PhD in Mechanical Engineering from the University of Witwatersrand, Johannesburg, South Africa. He currently specialises in mechatronics systems design, intelligent control and vibration mechanics.
By Ogedengbe I. I. Akintunde M. A. Dahunsi O. A. Bello E. I. Bodunde P.
DOI: https://doi.org/10.5815/ijisa.2022.02.02, Pub. Date: 8 Apr. 2022
The widespread adoption of Unmanned Aerial Vehicles (UAVs) can be traced to its flexibility and wide adaptability to various operating conditions and applications, comparably low cost of construction and maintenance and environmental friendliness as they can be easily configured for electric power. The use of electric power also favours its low noise applications such as surveillance. A major issue associated with surveillance, as addressed in this study is the compromise between Range and Endurance operation modes. The Range mode relates to being able to cover longer distances while the Endurance mode relates to spending longer times in the atmosphere for a fixed charge. Trying to balance the interplay of these parameters gave rise to a multi-objective optimization where the objectives are somewhat conflicting. This resulted in a set of Pareto solutions which are a set of design parameters (primarily angle of attack) that satisfy the joint requirements of the performance parameters of Range and Endurance. This study first considered a baseline aerodynamic design using traditional design methods. Design of Experiment techniques were then used to select the most favourable design points. This model was then used to build an input framework for Genetic Optimization algorithm deployed in the Global Optimization Toolbox of MATLAB. The result of this research shows that most of the region associated with medium angle of attack (AOA) setting (7 degrees) jointly satisfies good Range and Endurance performances with an average lift-to-drag ratio of 20 in the flight configuration considered. The implication of this result is that low velocity drag encountered in surveillance that requires a high AOA is largely reduced with the medium setting, albeit stabilized with other structural and aerodynamic settings, namely an aspect ratio of 13 and a taper ratio of 0.6.
[...] Read more.By Oyedeji O.I. Apalowo R.K. Dahunsi O. A. Audu A.
DOI: https://doi.org/10.5815/ijem.2020.06.01, Pub. Date: 8 Dec. 2020
Introduction of vibration to manufacturing operations such as casting and welding has proved to improve the physical and mechanical properties of manufactured parts. A vibration exciter is developed for the purpose of generating and inducing vibration, along different degrees of freedom, on objects placed on its surface. The equipment applies an eccentric mass drive system which gives the equipment an overall advantage in varying the vibration parameters. The acceleration of the vibratory motion of the equipment was measured using an accelerometer and oscilloscope set-up. The natural frequencies of the different vibration modes are also obtained from a developed mathematical model executed using the MATLAB Simulink software. The developed equipment successfully generated random sinusoidal vibrations of accelerations ranging from −5 m/s^2 to 8 m/s^2 along the principal axes and angular accelerations ranging from −40 rad/s to 40 rad/s about the pitch and roll axes. Natural frequencies of f_x = 3.78 Hz, f_θ = 7.94 Hz and f_φ = 9.89 Hz are obtained along the vertical, pitch and roll directions respectively. The presented results indicate that the developed machine successfully satisfied the proposed hypothesis of being able to measure vibrational characteristics along different degrees of freedom.
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