Iranian Society of Acoustics and Vibration and AvecinaJournal of Theoretical and Applied Vibration and Acoustics2423-476110220240701Sound quality of historical mosques in Tabriz in accordance with international standards12271497510.22064/tava.2023.1971148.1216ENFarzanehGholizadehAssistant Professor, Faculty of Architecture and Urbanism, Tabriz Islamic Art University, Tabriz, IRANAbbasGhaffariAssociate Professor, Faculty of Architecture and Urbanism, Tabriz Islamic Art University, Tabriz, IRANMohammad AliKaynejadProfessor, Faculty of Architecture and Urbanism, Tabriz Islamic Art University, Tabriz, IRANJournal Article20221122Sound is one of the important factors in creating a good feeling in a mosque and it can play a role as a sensory medium to communicate spiritually with God. Therefore, the acoustic standards have defined the optimal level for the mosque in the field of various variables. In order to compare the acoustic conditions of the use of the mosque with the standard limits, the present research has carried out field measurements and software analysis of the standing position in order to simulate the prayer position. Form and volume are the two considered architectural parameters and Background Noise (BN), Reverberation Time (RT), and Sound Pressure Level (SPL) are the three acoustic variables of the study. A total number of 15 historical mosques in Tabriz are divided into three large, medium, and small volume categories and five form categories have been tested. The reference of the study is ISO3382-1 and ISO3382-2 and the measurements were made with B&K equipment. In addition to the direct achievements, the results have been adapted to international standards and show that the acoustic situation in the historical mosques of Tabriz, regardless of their volume and form, produces sound in the range of 60 to 90 phones, and in terms of RT, have the suitable design from the volume point of view, but the lack of carpet flooring in some of them has increased the RT. The background noise in these examples is less than NC-25, which provides a quiet space for the user and provides the necessary concentration for individual worship.https://tava.isav.ir/article_714975_1353b86cb1c85f11a7426704a0016624.pdfIranian Society of Acoustics and Vibration and AvecinaJournal of Theoretical and Applied Vibration and Acoustics2423-476110220241119A parametric optimization of vortex bladeless generator233371534410.22064/tava.2024.2024948.1235ENSeyed SaeidMansouriPh.D. Candidate, Mechanical Engineering Faculty, Imam Hossein Comprehensive University, Tehran, IranMohammad RezaElhamiAssociate Professor, Mechanical Engineering Faculty, Imam Hossein Comprehensive University, Tehran, IranRohollahHosseiniAssistant Professor, Mechanical Engineering Faculty, Imam Hossein Comprehensive University, Tehran, Iran0000-0002-3618-6367Journal Article20240315A vortex-bladeless turbine is a device that works with vortex-induced vibration, which is generated by wind energy. It is one of the innovative devices for wind energy harvesting with some remarkable advantages compared to classical turbines. Such wind turbines have numerous advantages, including less maintenance than classical windmills, lower manufacturing costs, and easier installation. Vortex's nobility comes from its spectacular form of harvesting energy by vibration. The mast vibrates in the wind, with lift force made with Von-Karman vortices when a moving air cross-passes over a mast (with a mean diameter of the mast <strong>D</strong>) structure. At the lower part of the mast, an elastic rod (carbon fiber) moves an alternator and harvests electricity with the least parts in contact. To optimize this technology for harvesting the potential energy, one of the critical parameters is the mean diameter D, which is analytically studied to have the largest displacement amplitude at the tip of the mast. To this end, the bladeless generator is simulated as a one-degree-of-freedom system moving transverse with the flow direction. The mass-damping parameter (m*ζ), which depends on a mast and core fabric, is investigated. Air forces are extracted from experimental experiences, and fabrics are determined at the design stage according to references (carbon fiber for the core and carbon glass for the mast). The velocity of the air is determined according to where the bladeless generator will be installed. In the end, the results are verified by CFD methods in fluent software. ICEM software is used for meshing the 2-dimensional model. The Piso algorithm and kω-sst model are applied to model the airflow to solve the problem.https://tava.isav.ir/article_715344_0b761325b455261085445e7de6de93f6.pdfIranian Society of Acoustics and Vibration and AvecinaJournal of Theoretical and Applied Vibration and Acoustics2423-476110220250211Design and experimental evaluation of road excitation simulator actuated by electro-hydraulic system344971958310.22064/tava.2024.2029276.1240ENMohammad JavadAziziM.Sc., Faculty of Mechanical Engineering, Sahand University of Technology, Tabriz, 513351996, IRANMehdiMirzaeiProfessor, Faculty of Mechanical Engineering,Sahand University of Technology, Tabriz, 513351996, IRAN0000-0002-6359-7524SadraRafatniaAssistant Professor, Faculty of Mechanical Engineering, Sahand University of Technology, Tabriz, 513351996, IRAN0000-0002-3517-6810TahaFalahati NodehPh.D., Faculty of Mechanical Engineering, Sahand University of Technology, Tabriz, IRANJournal Article20240516This study focuses on the design and experimental evaluation of a road excitation simulator driven by an electro-hydraulic system. The simulator is employed to create road irregularities, which are then applied to the vehicle platform during laboratory testing. To generate the desired road inputs by the simulator, a fuzzy tracking control law is developed based on expert knowledge of the system derived from displacement data obtained from a linear potentiometer transformer. The fuzzy controller utilizes the Mamdani structure to compute the required voltage for the electro-hydraulic directional valves. This controller is implemented through the LabView interface, and its performance is evaluated and compared against a proportional-integral-derivative (PID) controller under various road inputs. Experimental results from tests conducted on a fabricated platform in the laboratory demonstrate that the fuzzy method offers superior accuracy and reliability compared to the PID controller. The designed simulator is capable of generating a variety of standard road inputs for testing the vibrations of various vehicles and their cargo.https://tava.isav.ir/article_719583_b521572a02f65c8dc555daf1b4129e7e.pdfIranian Society of Acoustics and Vibration and AvecinaJournal of Theoretical and Applied Vibration and Acoustics2423-476110220240701Exploiting an arc-shaped rotary magneto-piezoelastic energy harvester: Theoretical and experimental investigations5076719584ENImanFakhari GolpayeganiFaculty of Mechanical Engineering, K.N. Toosi University of Technology, Tehran, IRANMechanical Engineering Group, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan, IRANAli AsgharJafariFaculty of Mechanical Engineering, K.N. Toosi University of Technology, Tehran, IRANJournal Article20240917This article investigates a new piezoelectric harvester for extracting energy from rotational motions. The harvester''s geometry is selected as a curve to increase the energy harvesting density. For its optimal performance across a wide range of rotational speeds, the harvester is excited by a non-linear magnetic force. Simultaneously with the rotation of the shaft and the attached magnet and creating a magnetic force, the magnet at the tip of the beam is excited, causing the curved piezoelectric element installed in the harvester to repeatedly deform and generate electrical energy. Electromechanically coupled differential equations are developed based on Hamilton''s principle, and the Lagrange equations and piezoelectric relationships are extracted and numerically solved. This research accurately calculates the force between the magnetic dipole and a new time and displacement-dependent correction factor. This model is used to investigate how the output voltage and power of the harvester are affected by the rotational speed, magnetic gap, number of excitation magnets, and circuit resistance in both the time and frequency domains. Most significantly, the theoretical modeling results are compared with experimental data obtained from constructing a prototype and conducting numerous tests. The results indicate that reducing the magnetic gap and increasing the number of magnets to a certain extent will increase the voltage and output power. The maximum power and maximum power density extracted during excitation with four magnets at a rotational speed of 986 rpm are 1523.5 μW and 11.37 μW/mm<sup>3</sup>, respectively, demonstrating the superior performance of the designed system.https://tava.isav.ir/article_719584_4936abdb87f1129b37da8565a696987f.pdfIranian Society of Acoustics and Vibration and AvecinaJournal of Theoretical and Applied Vibration and Acoustics2423-476110220240402A hybrid machine learning and particle swarm system for configuring holes on cantilever beams to achieve desired natural frequencies516472015010.22064/tava.2025.2040402.1244ENAmir HosseinRabieeSchool of Mechanical Engineering, Arak University of Technology, 38181-41167, Arak, IRANAmir MohammadJalaliSchool of Mechanical Engineering, Arak University of Technology, 38181-41167, Arak, IRANJournal Article20240905In this paper, a hybrid machine learning/optimization system is developed to identify the optimal configuration of holes on a cantilever beam to achieve a desired natural frequency. Based on a design of experiments, 100 configurations are selected from the vast possible combinations of placing five holes on a 5x21 matrix grid over the beam. The natural frequencies for these configurations are obtained using frequency analysis in COMSOL. A dataset containing the hole configurations and their corresponding normalized first natural frequency is constructed to build a machine-learning model using the LightGBM method. The particle swarm optimization algorithm is employed to find the optimal hole configuration that yields the desired natural frequency. The results demonstrate the success of the developed hybrid system, as the machine learning model accurately predicts both the training and testing data. Additionally, the optimization algorithm successfully identifies hole configurations that closely match the desired natural frequency in various test cases, validating the system's effectiveness.https://tava.isav.ir/article_720150_55d574c9d56d47bbcd58d9d05ddd0172.pdfIranian Society of Acoustics and Vibration and AvecinaJournal of Theoretical and Applied Vibration and Acoustics2423-476110220250418Acoustic energy harvesting from sonic crystals with non-square lattices using piezoelectric patch657672163710.22064/tava.2025.2023906.1233ENSaeedSharifi MoghaddamDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IRAN.0000-0001-8626-1962SaeedZiaei-RadDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IRAN.ReihanehHadipour HafshejaniDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IRAN.RezaTikaniDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IRAN.Journal Article20240228The field of energy harvesting from the environment has emerged as a significant area of research in recent years. Acoustic energy represents a natural source of mechanical energy that can be converted into electrical energy using metamaterials and piezoelectric materials. A defect was introduced into a regular lattice of the crystal. At the point of defect, a concentration of sound pressure was created, and by installing the PVDF piezoelectric patch, mechanical energy can be converted into electrical energy. In this study, an effort was made to identify a suitable model for maximum acoustic energy harvesting. The effect of various lattices, including circular, rhombus, rectangular, square-rhombic, square-rectangular, and rhombus-rectangular lattices, on the sound pressure level (SPL) and energy harvesting was investigated. Additionally, the impact of modifying the position of the defect and increasing the number of defects on the SPL was examined. The simulation results were calculated using COMSOL Multiphysics 6.0. The results were validated by comparing them with those of previous studies. Findings demonstrated that a square-rhombic lattice can provide the highest SPL and, consequently, the highest harvested energy. In the square-rhombic lattice, using the optimal resistance of 15 kΩ at the frequency of 4220.4 Hz yielded a voltage and power of 11.34 mV and 4.15 nW, respectively.https://tava.isav.ir/article_721637_feff3abc6ab1c5a09c3c537a1fc7b8a0.pdf