Applied Engineering Letters

139-147

Authors: Ágota Bányai

Manufacturing and service companies in different sectors are trying to green their supply chains in two ways: by optimizing processes and by using green technologies such as electric vehicles. Cross-docking offers a good solution for optimizing supply chain processes. The aim of this research is to investigate how cross-docking supply with electric vehicles can lead to energy efficient solutions and emission reduction. The scientific novelty of this research is the integration of a process improvement solution and the application of advanced technology through optimization. The presented functional model, mathematical model and its solution algorithm are suitable to demonstrate the economic feasibility of applying a cross-docking facility and solving the transportation tasks with e-trucks for a conventional supply chain. Based on the numerical studies presented, it can be concluded, that the proposed solution can significantly contribute to the optimization of local and global supply chains, reducing the ecological footprint of supply chains both locally and globally. As the analysis of case studies shows, it is possible to reach an energy efficiency improvement of about 40%, which can also lead to a significant GHG emission up to 30%.

158-166

Authors: Mahdi Tabatabaei Malazi, Muharrem Hilmi Aksoy, Abdulkerim Okbaz

This paper presents a numerical investigation of the three-dimensional flow field with deformations of two tandem rectangular cylinders. The one-way Fluid-Structure Interaction (FSI) method simulated the deformation domain. The Realizable k-ε turbulence model was utilized to model turbulent flow simulation in the three-dimensional flow domain. The hydrodynamic forces, deformations, and stresses were calculated for different spacing configurations between the rectangular cylinders. Structural steel was chosen for the rectangular cylinders, while water was chosen for the fluid domain. The flow inlet velocity was maintained at 5 m/s for all simulations, resulting in a corresponding Reynolds number of 5×105 based on free stream velocity and cylinder width. The numerical results demonstrated that the cylinder spacing significantly affected the cylinders’ deformation. The distance ratio between the two tandem rectangular cylinders to the cylinder height (x/H) was increased from 1 to 5. The front rectangular cylinder endured a higher pressure load than the rear rectangular cylinder, with the maximum deformation of the front cylinder found to be 7.15 mm. Due to the lower pressure on the rear rectangular cylinders, deformation varied between 0.98 mm and 6.02 mm as x/H changed from 1 to 5. This research provides valuable insights into the deformation behavior of tandem rectangular cylinders in three- dimensional flow fields.

175-182

Authors: Borivoj Novaković, Ljiljana Radovanović, Držislav Vidaković, Luka Đorđević, Branislava Radišić

This study presents the application of the Fault Tree Analysis (FTA) method in analyzing the reliability of a wind turbine power plant. Examining all crucial system components and simulating potential failure probabilities demonstrated the system’s overall reliability using two different coefficient simulations. This approach aims to identify which elements have the most significant impact on the reliability of wind turbine systems and, consequently, determine the critical points of the analyzed system. The displayed fault tree and appropriate tabular analysis present comparative analyses between these two simulations. From both case examples, it can be concluded that the system’s generator plays a crucial role in influencing the overall reliability. By applying Boolean algebra and input coefficients for two cases, the values of potential wind turbine failures were obtained: in the first case, 11.7%, while in the second case, the percentage is 5.7%.