Amirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29379420251001The Role of Fresh Air Nozzle Orientation and Warehouse Dimensions in Modulating Airflow and Temperature in Pharmaceutical Warehouses: A Comparative Study343356574110.22060/ajme.2025.23826.6160ENHamedSafikhaniDepartment of Mechanical Engineering, Faculty of Engineering, Arak University, Iran0000-0002-9732-6861SomayehDavoodabadi FarahaniSchool of Mechanical Engineering, Arak University of Technology, Arak, Iran0000-0003-1231-1538HadiBagheri HaghighiDepartment of Mechanical Engineering, Faculty of Engineering, Arak University, IranJournal Article20250109This study investigates the effects of fresh air inlet angle, warehouse height, and shelf occupancy on airflow and temperature distribution in pharmaceutical warehouses through parametric and multi-objective optimization analyses. A two-dimensional model of the warehouse is developed and analyzed using Computational Fluid Dynamics via ANSYS Fluent software. Results indicate that increasing the warehouse height from 3 to 5 and 7 meters leads to reductions in average temperature by 1.4% and 2.2%, respectively, and temperature variation by approximately 32% and 42.2%. Lower shelf occupancy provides the most favorable thermal conditions, while medium occupancy results in the poorest performance in terms of both average temperature and uniformity. As the air inlet angle increases from vertical, temperature rises and uniformity deteriorates. Horizontally, shelves farther from the symmetry axis exhibit higher temperatures and less uniformity. Vertically, middle shelves show better thermal performance than upper or lower ones. Additionally, increasing the warehouse height reduces average air velocity. Optimization results reveal the best configuration by balancing temperature and its uniformity. These findings provide insights into improving the thermal environment of pharmaceutical storage spaces to preserve drug quality and reduce energy consumption, guiding design improvements for Heating, Ventilation, and Air Conditioning systems in such facilities.https://ajme.aut.ac.ir/article_5741_edea298442a67de045e88dfb6e5ea4a2.pdfAmirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29379420251001Enhancing the Reliability of Control Systems Using an Improved Deep Reinforcement Learning Framework357372574610.22060/ajme.2025.24021.6172ENMaryamBarekatainDepartment of Electrical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran.NeginSayyafDepartment of Electrical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran.0000-0002-1315-5250Journal Article20250330This paper presents an improved framework for deep reinforcement learning algorithms integrating online system identification, based on the Dyna-Q architecture. The proposed framework is designed to tackle the challenges of both Multi-Input Multi-Output and Multi-Input Single-Output systems in complex, industry-relevant environments, thereby significantly enhancing adaptability and reliability in industrial control systems. It should be noted that in the suggested novel framework, the system identification and model control processes run in parallel with the control process, ensuring a reliable backup in case of faults or disruptions. To verify the efficiency of the aforementioned approach, comparative evaluations in the presence of three of the most common deep reinforcement learning algorithms, i.e. Deep Q Network, Deep Deterministic Policy Gradient, and Twin Delayed Deep Deterministic Policy Gradient, are conducted on industry-relevant environments simulations available in OpenAI Gym, including the Cart Pole, Pendulum, and Bipedal Walker, each chosen to reflect specific aspects of the novel framework. Results demonstrate that the proposed method for leveraging both real and simulated experiences in this framework improves sample efficiency, stability, and robustness.https://ajme.aut.ac.ir/article_5746_63a99723ebb3af94d52b474c3b21dbe1.pdfAmirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29379420251001Three-Dimensional Optimization of Blade Lean and Sweep for a Transonic Axial Compressor and Investigation of the On-Design and Off-Design Engine Performance373402576610.22060/ajme.2025.23787.6159ENMojtabaHeidarian ShahriDepartment of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran0009-0009-6769-0361AliMadadiDepartment of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran0000-0002-6257-5454RominaAhadianDepartment of Aerospace Engineering, Amirkabir University of Technology, Tehran, IranJournal Article20250223Recently, optimization methods have been considered by authors to enhance the turbo-machines' performance. In this article, the genetic algorithm (GA) and artificial neural network (ANN) with computational fluid dynamics (CFD) are being coupled, and the optimization of NASA Rotor-67, an axial compressor, has been simulated. The compressor flow field is simulated with CFD, and the results proved the excellent validation with experimental data. The rotor leaned and swept parametrization was modeled, and the results are improvements in design objective functions: pressure ratio, isentropic efficiency, and mass flow rate. According to the best-optimized case results, the mass flow rate, pressure ratio, and isentropic efficiency of the design point have been increased by about 2.020%, 1.297%, and 0.174%, respectively. Improving the convergence of surface streamlines in delaying the shock on the blade is another factor in improving the optimal rotor's performance compared to the base one.<strong> </strong>Then, the effect of the best-optimized rotor is studied at the on-design and off-design steady-state performance of a turbojet engine. The matching code has been worked out by solving compatibility equations using the characteristic maps. The results show that Thrust has improved at design and off-design speeds.https://ajme.aut.ac.ir/article_5766_3465ab6e0c21086020e382f09a482ced.pdfAmirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29379420251001Presenting of a novel high-order sliding mode control based on Lyapunov theory403412577010.22060/ajme.2025.23879.6163ENMasoudAbdolmohammadiFaculty of Mechanical Engineering, Shahrood University of Technology, Shahrood, IranHabibAhmadiFaculty of Mechanical Engineering, Shahrood University of Technology, Shahrood, IranJournal Article20250201In this paper, we present a novel control scheme based on high-order sliding mode control (HOSM) for nonlinear systems under uncertainty. The stability and robustness of the proposed controller have been proven using Lyapunov’s method. The controller not only withstands uncertainties and disturbances but also significantly reduces the amplitude and frequency of chattering compared to existing algorithms. Furthermore, the suggested high-order sliding mode controller provides the ability to adjust the chattering frequency through its parameters. Initially, the sliding surface is introduced for second-order dynamics, followed by the necessary stability assumptions to ensure system stability. Then, a new second-order sliding mode controller is proposed, and its stability is verified through Lyapunov’s method. Detailed simulation results using a planar robot demonstrate the controller's performance, which is compared with existing algorithms. The results confirm that the new controller effectively manages uncertainties, ensuring stable system control. The proposed controller not only reduced the frequency of chattering but also decreased the steady-state error for a two-link robot. Simulation shows the decrease in root mean square error compared to twisting and super-twisting controllers.https://ajme.aut.ac.ir/article_5770_4b7a55505729b7f664e7222960e9c2d5.pdfAmirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29379420251001A Unified Gram-Schmidt–Ritz Solution for Vibration Analysis of Nanoplates with Elastic Boundary Conditions413430579310.22060/ajme.2025.24153.6178ENHosseinPakdamanDepartment of Civil Engineering, K.N. Toosi University of Technology, Valiasr Ave., Tehran, IranJournal Article20250516A novel and unified approach is presented for analyzing the free vibration of rectangular nanoplates with elastic boundary conditions. The theoretical modeling is achieved using the nonlocal Mindlin plate theory, which accounts for the size-dependent behavior of nanoplates, while the artificial spring technique is employed to accommodate a wide range of boundary conditions, including classical boundary conditions, elastic boundary conditions, and their combinations. The governing equations of motion are derived using the virtual displacement principle, followed by the application of the weighted residual method to obtain the nonlocal quadratic functional. The Rayleigh-Ritz method, employing Gram-Schmidt polynomial series as the admissible displacement functions, is then utilized to solve the eigenvalue problems associated with the free vibration of nanoplates. The present approach is validated through a series of comparison and convergence studies, which demonstrate its high accuracy and low computational cost. Finally, parametric numerical investigations are conducted to elucidate the effects of variations in spring stiffness on the natural frequencies of nanoplates. It is shown that the proposed method can easily compute the natural frequencies of nanoplates with elastic boundary conditions.https://ajme.aut.ac.ir/article_5793_fe256faf97c200de0f7486ddf56c02f6.pdfAmirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29379420251001Investigating the Effect of Seat Suspension System and Cushion on the Dynamic Behavior of the 214 Helicopter Pilot's Body431446579710.22060/ajme.2025.23838.6161ENSeyed MohammadKamaliDepartment of Aerospace Engineering, Shahid Sattari Aeronautical University of Science and Technology, Tehran, Iran0009-0000-5214-2412AliNouriDepartment of Aerospace Engineering, Shahid Sattari Aeronautical University of Science and Technology, Tehran, Iran0000-0002-2080-6306HeshmatallahMohammad KhanloDepartment of Aerospace Engineering, Shahid Sattari Aeronautical University of Science and Technology, Tehran, Iran0009-0005-4621-2652HadiSabouriDepartment of Mechanical Engineering, Faculty of Engineering, Kharazmi University, Tehran, IranJournal Article20250129In this study, the influence of the stiffness and damping characteristics of the pilot seat cushion in the Bell 214 helicopter is investigated as two critical factors in reducing the transmission of vibrations to the pilot’s body. Since the dominant vibrations in the Bell 214 occur at low frequencies, typically between 2 and 15 Hz, the seat suspension system is not effective in this range, and the seat cushion plays a more significant role in vibration isolation. First, the biodynamic response of the human body is validated by comparing the results with existing experimental and analytical data related to helicopter vibration exposure. Then, the biodynamic equations of motion are analyzed using a four-degree-of-freedom seated human model under various configurations, with and without suspension and seat cushioning. Finally, the frequency domain response is examined through three-dimensional plots to evaluate the effect of different cushion stiffness and damping values. The results indicate that selecting optimal mechanical properties for the cushion can significantly enhance pilot comfort and play an effective role in reducing vibration-induced physical injuries.https://ajme.aut.ac.ir/article_5797_034260c0426cf36118803ce0df4457fd.pdf