Original Article
Maintenance and repair of the engine, wing and body of unmanned aerial vehicles/technology/construction/...
davood moosavian; Morteza Ahmadi Nohedani
Volume 3, Issue 1 , May 2024, Pages 1-18
Abstract
A new method for cooling the combustion chamber walls, it is cooled by the bidirectional vortex Flow. Combustion stability, reducing the temperature of the combustion chamber walls and reduces losses and increase efficiency and uniformity are the properties of the vortex combustion engine. In similar ...
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A new method for cooling the combustion chamber walls, it is cooled by the bidirectional vortex Flow. Combustion stability, reducing the temperature of the combustion chamber walls and reduces losses and increase efficiency and uniformity are the properties of the vortex combustion engine. In similar circumstances the volume of flame the vortex engine is greater than the volume of flame at common axial engine. However; temperature of the Wall of the combustion chamber of the vortex engines less than temperature of the Wall of the combustion chamber of the engine Axial. Because cooled by the external vortex. In this study, was carried out Simulation and Numerical Solution the combustion chamber a special vortex engine in conditions single phase gaseous to fuel hydrogen and oxidant oxygen and assuming incompressible flow and irrespective of effect nozzle In order to simplify for review conditions governing on flow the combustion chamber. Examination of the streamlines shows a forced vortex in the center of the core and a free vortex around the core. The simulation results show that the pitch of the Stream lines near the roof is very small and the intensity of the flow rotation is high, which causes the maximum mixing of fuel and oxidizer. The flame is surrounded by an external vortex. In the simulated chamber, by increasing the distance from the edge of the stairs to the ceiling, the mixing and combustion will increase, and as a result, we will have an increase in the temperature of the wall.
Original Article
Radar/thermodynamics/heat transfer/fuel and combustion/energy/...
samane Zargar; Mohammad Hassan Djavareshkian
Volume 3, Issue 1 , May 2024, Pages 19-47
Abstract
The research investigates the growth of ice on the wing of a UAV, both with and without a winglet, and its effects on aerodynamic coefficients at low Reynolds numbers using a numerical method. The wing configuration is rectangular, employing the NACA0020 airfoil cross-section. Simulations were performed ...
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The research investigates the growth of ice on the wing of a UAV, both with and without a winglet, and its effects on aerodynamic coefficients at low Reynolds numbers using a numerical method. The wing configuration is rectangular, employing the NACA0020 airfoil cross-section. Simulations were performed using a numerical method based on the finite volume method, a pressure-based algorithm, and second-order upwind scheme for convective flux calculation. Turbulent flow is modeled using the Spalart-Allmaras turbulence model. For ice modeling, the FENSAP-ICE commercial software, a modular ice simulation system, was utilized. The iterative ice accumulation simulation process includes successive calculations of airflow, water droplet paths, collection efficiency, and heat transfer balance to determine the shape of the accumulated ice. Calculations were conducted at Reynolds numbers of at an angle of attack of 10 degrees. Results indicate that the ice profile formed on the leading edge of the airfoil generates a swirling flow in this region due to depressions above and below the ice mass. This swirling flow increases the back pressure coefficient and decreases the drag coefficient compared to the wing without ice. Adding a winglet alters the airflow and reduces air resistance by controlling the induced vortices from the wingtip, thereby increasing lift and reducing drag. Consequently, the airflow speed increases, reducing ice accumulation and enhancing the aerodynamic efficiency of the wing.
Original Article
Defense mechanics/navigation/control/...
sariyeh Moghtader Arbat sofla; A.H. Mazinan; M.J Mahmoodabadi
Volume 3, Issue 1 , May 2024, Pages 48-65
Abstract
In recent years, due to the widespread use of nonlinear under-actuated systems, many efforts have been made to design a controller compatible with these systems. In fact, the defect in stimulation is done in order to reduce the number of system acctuators, in order to lighten the mechanism and reduce ...
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In recent years, due to the widespread use of nonlinear under-actuated systems, many efforts have been made to design a controller compatible with these systems. In fact, the defect in stimulation is done in order to reduce the number of system acctuators, in order to lighten the mechanism and reduce the cost of production. Such applications require a high degree of precision and innovation in control and sustainability.This paper proposes an optimal adaptive control method for the stabilization of under-actuated fourth-order balls and beam system, which is a classical example of inherently unstable systems. The basic structure for this controller is the feedback linearization (FBL) technique, while a sliding surface is applied using the sliding mod along with an adaptive method to calculate the interest coefficients. In addition, the control coefficients are optimized using the hummingbird algorithm by considering two opposing objective functions. Finally, the effectiveness of the proposed method for controlling the nonlinear ball and beam system is investigated. The results of the simulations show the high efficiency of the proposed method compared to similar works.
Original Article
Passive defense (detection, decontamination and protection and safety - chemical, biological and nuclear, etc.)
Maryam Shokoohi; Mohsen Afsharchi; Hamed Shah-Hosseini
Volume 3, Issue 1 , May 2024, Pages 66-96
Abstract
The Incident Command System (ICS) requires agents who routinely deal with a large number of search and rescue tasks. In addition, responses must operate in highly uncertain and dynamic environments where new tasks emerge and may spread across the disaster landscape. Therefore, finding the optimal and ...
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The Incident Command System (ICS) requires agents who routinely deal with a large number of search and rescue tasks. In addition, responses must operate in highly uncertain and dynamic environments where new tasks emerge and may spread across the disaster landscape. Therefore, finding the optimal and correct allocation to complete all activities in a reasonable time is a big computational challenge.In Iran, the Incident Command System acts asistematic and lack of intelligence, and the presence of a correct decision-making system that has functionality and makes correct and quick decisions is very important.This article presents a method for solving the allocation problem, which is a distributed constraint optimization problem. This method uses Markov decision techniques and learning techniques such as learning automata.The results of simulations and experiments show that the existence of the learning technique and the decentralized behavior of agents can replace the past methods and compensate for the lack of previous methods. The proposed method can perform 85% better than the centralized method and previous methods and is much better in terms of convergence and time.
Original Article
Quantum science
Hossein Davoodi Yeganeh
Volume 3, Issue 1 , May 2024, Pages 97-109
Abstract
Quantum computing can be more efficient than classical computing for many problems that have no solution with classical methods. Among the various quantum computing models, the adiabatic quantum computing model is widely used in the field of graph theory. The problem of finding the shortest path can ...
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Quantum computing can be more efficient than classical computing for many problems that have no solution with classical methods. Among the various quantum computing models, the adiabatic quantum computing model is widely used in the field of graph theory. The problem of finding the shortest path can be modeled using graphs, and this problem is of great interest due to its practical applications, such as in the movement of drones. In this article, the problem of the shortest path is investigated and solved using quantum adiabatic calculations. The problem is first mapped to a Hamiltonian expression, and then the dynamics of this Hamiltonian are studied using quantum adiabatic calculations. This model is then applied to a problem in the movement of drones, and the results show that quantum computing can be used effectively to solve shortest path problems in the movement of drones.
Original Article
Electromagnetism, electronics and cyber-electromagnetism (disturbance in waves, jamming, strong microwave waves, etc.)
milad nosrati; Abdulsoul Gerami; samad aghamohamadi; Mohamad Khakzad; Mehdi Mahdi HeshmatiRad
Volume 3, Issue 1 , May 2024, Pages 110-133
Abstract
Today, there is a growing trend in the public health sector to use smart technologies for monitoring and tracking purposes in military and defense systems. In this article, the construction of a wearable antenna in non-medical bands has been investigated. To study near-body antennas in terms of effects ...
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Today, there is a growing trend in the public health sector to use smart technologies for monitoring and tracking purposes in military and defense systems. In this article, the construction of a wearable antenna in non-medical bands has been investigated. To study near-body antennas in terms of effects and proper performance, this work uses a multi-layer phantom. The design of the miniature antenna in four frequency bands has been done in the first proposed model and the construction of the single band antenna for the 2.4 GHz ISM band has been done in the second design. Our goal is to design efficient miniaturized antennas through miniaturization techniques, i.e. using orthogonal structure and increasing path length. The user safety check of the antenna shows that the SAR is within the standard range. To achieve the design objective, a linear polarization winding structure is presented. The connection inside, outside and inside the body with linear antenna is the purpose of proposing meandering structures. The prepared antenna works in the frequency range of 2.4 to 2.5 GHz. A comparison of the results shows a good overlap between the measured and simulated results. The fabricated miniature antenna also provides a gain in the range of 0.56 to 2dBi. The efficiency obtained in the design of two antennas is more than 90%.
