Cover

Aims and Scope
Editorial Board

1. Green Hydrogen and the Beginning of a New Energy Era

Maher A.R. Sadiq Al-Baghdadi ^1,2

¹ Kufa Centre for Advanced Simulation in Engineering (KCASE), Faculty of Engineering, University of Kufa, Najaf, Iraq.

² Fuel Cell Research Center, International Energy and Environment Foundation, Najaf, P.O.Box 39, Iraq.

Abstract: Hydrogen is a very important fuel of our secure and clean energy future. Hydrogen will be the fuel of the future and gradually it will replace all current fossil fuels. Hydrogen can be used as a fuel for vehicles, to heat homes and offices, to produce electricity, and to fuel ships and aircraft. The present work provides an overview of hydrogen as an alternative fuel, which can be used in internal combustion engines and in fuel cells.

Volume 12, issue 1, 2021, pp.1-18.

2. CFD Simulations of Tubular Archimedean Screw Turbines Harnessing the Small Hydropotential of Greek Watercourses

Alkistis Stergiopoulou ¹, Vassilios Stergiopoulos ²

¹ Institut für Wasserwirtschaft, Hydrologie und Konstruktiven Wasserbau, B.O.K.U. University, Muthgasse 18, 1190 Vienna, (actually Senior Process Engineer at the VTU Engineering in Vienna, Zieglergasse 53/1/24, 1070 Vienna, Austria).

² School of Pedagogical and Technological Education, Department of Civil Engineering Educators, ASPETE Campus, Eirini Station, 15122 Amarousio, Athens, Greece.

Abstract: This paper presents a short view of the first Archimedean Screw Turbines CFD modelling results, which were carried out within the recent research entitled “Rebirth of Archimedes in Greece: contribution to the study of hydraulic mechanics and hydrodynamic behavior of Archimedean cochlear waterwheels, for recovering the hydraulic potential of Greek natural and technical watercourses”. This CFD analysis, based to the Flow-3D code, concerns typical Tubular Archimedean Screw Turbines (TASTs) and shows some promising performances for such small hydropower systems harnessing the important unexploited hydraulic potential of natural and technical watercourses of Greece, of the order of several TWh / year and of a total installed capacity in the range of thousands MWs.

3. Transverse vibration of cracked graded shear beam with axial motion

Nabaa A. Bichay, Talib Eh. Elaikh

Mechanical Engineering Department, University of Thi-Qar, Iraq.

Abstract: This paper presents a study on the vibration characteristic of open edge cracks graded moving shear beam. The material property gradient is based on the distribution of the power-law in the direction of the beam thickness. The vibration equation is obtained depending on the precept of Hamilton principle and resolved by the extension of Galerkin's approach. To represent the cracking in the beam, a rotational spring is used. The effects of the axial velocity, gradient index, and cracking parameters on vibration characteristics are observed. Furthermore, the shapes of the model are determined for simply supported cracked moving graded shear beam. The results show that the natural frequencies decrease with the rise in the axial velocity, the crack depth, and the material property index. The percentage of decrease in the natural frequencies as a result of increase in crack depth ratio is 40%.

4. Manufacturing and mechanical behavior investigation of prosthetic below knee socket by using natural kenaf fiber

Sumeia A. Mechi, Muhannad Al-Waily

Department of Mechanical Engineering, Faculty of Engineering, University of Kufa, Iraq.

Abstract: This paper presented the investigation of the effect of adding natural fiber kenaf fiber on the stress and deformation in below-knee socket prosthetic structures manufactured from composite laminated materials with various reinforcement fibers. This work included theoretical, experimental and numerical study, in theoretical part the weight of the patient on the remaining limb was analyzed mathematically using Matlab 2018 a program, the result of the pressure was 165 Kpa. As for experimental part, the artificial socket was manufactured from the second proposed composite materials with kenaf, testing the ground reaction force (GRF), as the results showed that the proportion of similarity between the uninjured leg and healthy is 96%. Numerical analysis part  using the finite element method was adopted to estimate the Von Mises stresses and deformation behaviors for the below-knee prosthetic structures through ANSYS 2020 R2, The simulation using the mechanical properties of the relevant composite materials taken from previous published and  the pressure generated from the mathematical equations was compared with the results using the pressure readings obtained from the experimental test F-Socket readings of a similar patient condition as input to the ANSYS program. The results of the composite material using kenaf showed that the highest value of Von-Mises stress is equal to (34.14 Mpa) for the experimental F-Socket test, while the value (48.9 MPa) was obtained from theoretical part, as the stress was reduced by the lamination with kenaf in the experimental F-Socket test (43.23%) and theoretically (10%), to reduces the deformation of the material and comfort of the patient during movement. Finally, the different between the results was calculated for the theoretical and experimental F-Socket analyzes were acceptable values.