Scientific extention
Propulsion/Thermodynamics/Heat Transfer/Fuel and Combustion/Energy/...
jamasb pirkandi; AliReza Zolfi; Gholam Reza Hashemzadeh
Articles in Press, Accepted Manuscript, Available Online from 28 February 2023
Abstract
Studies show that the analysis of the first law in air propulsion systems alone is not sufficient, and for a complete study of a system, the second law and exergy analysis should also be considered. Thermodynamic analysis of air-breathing engines, especially Turbojet, Turbofan and Turboprop engines, ...
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Studies show that the analysis of the first law in air propulsion systems alone is not sufficient, and for a complete study of a system, the second law and exergy analysis should also be considered. Thermodynamic analysis of air-breathing engines, especially Turbojet, Turbofan and Turboprop engines, with the aim of studying their performance has attracted the attention of many researchers in the last decade. The main purpose of this study is to review and present the latest research findings in this field focusing on Turbojet, Turbofan and Turboprop engines. The results of further research show that the combustion chamber and afterburner are the two most important parts of air engines in which the most exergy destruction occurs. On the other hand, the study and analysis of engine exergy off design point is also an important issue that has been considered in recent years.
Scientific extention
Aerodynamics/Fluid Mechanics/Aeroacoustics/...
Ali Moradi; Alireza Hejazizadeh
Articles in Press, Accepted Manuscript, Available Online from 28 February 2023
Abstract
Helicopters can be a source of loud noise. The high production noise of helicopters makes them unsuitable for densely populated areas, especially in low-flying conditions. This study examines methods and offers solutions to reduce or eliminate the noise produced by helicopters. Several methods have been ...
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Helicopters can be a source of loud noise. The high production noise of helicopters makes them unsuitable for densely populated areas, especially in low-flying conditions. This study examines methods and offers solutions to reduce or eliminate the noise produced by helicopters. Several methods have been considered to reduce the noise produced. Solutions such as muffler for motors, use of modulated blade spacing, X-force control, reduced tip speed, blade tip modification, airfoil tailoring, Increasing the number of main rotor blades, active blade control and variable diameter rotor in The rotor and the use of the strut in the gearbox were introduced. According to the studies conducted in the present study, combined methods haveas the best noise reduction. although Independent methods reduce noise, depending on the amount of reduction required in the targeting, combining the methods can be achieved the appropriate answer.
Scientific extention
Life Sciences/Environment/Plant Physiology/Animal Physiology/Remote Sensing/...
Halimeh Hassanpour
Articles in Press, Accepted Manuscript, Available Online from 28 February 2023
Abstract
Light is as an environmental factor affecting plant growth. So far, various light sources have been used to grow plants in closed systems and space studies. Traditional light sources have some problems and are not suitable for space research. The biggest problem of them is the need for the high energy ...
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Light is as an environmental factor affecting plant growth. So far, various light sources have been used to grow plants in closed systems and space studies. Traditional light sources have some problems and are not suitable for space research. The biggest problem of them is the need for the high energy source, power supply weight, and heat production. LED light spectra were designed to solve plant cultivation problems in space for the first time and are recently used in terrestrial research such as greenhouses and plant cultivation rooms. The LED spectra have different colors, but laboratory studies are needed to determine the plants' involvement for these spectra. In this study, LED light technology, effect of spectra on the growth, production of metabolites and optical receptors are investigated.
Science and Technology
Design/System/Reliability/Flight Competence/Flight Testing/...
Hossein Sadati; Amirhossein Adami; Mohammad mehdi Ebadi
Articles in Press, Accepted Manuscript, Available Online from 12 March 2023
Abstract
In recent years, the use of air taxis as a suitable solution for transporting cargo and passengers, has been considered especially in short distances and in the city. Complex systems, such as air taxis, are involved in several subsystems with interacting and sometimes conflicting effects are difficult ...
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In recent years, the use of air taxis as a suitable solution for transporting cargo and passengers, has been considered especially in short distances and in the city. Complex systems, such as air taxis, are involved in several subsystems with interacting and sometimes conflicting effects are difficult to be derived. Modern optimal design methods such as multidisciplinary design optimization can derive the optimal design while satisfying all the constraints and limitation. In this article, multidisciplinary design optimization of an air taxi is discussed. The optimization framework is selected based on AAO by considering structure, aerodynamics, flight mechanics, propulsion and electrical power. Total mass of air taxi is selected as cost function. Finally, the optimal results are compared and evaluated with the results of two classical design methods including "weight estimation" and " sensitivity of design coefficients". The results confirm the improvement of optimal solution with compare of classical methods.
Scientific extention
Aviation/Piloting/Flight Care/Safety/Standard/Avionics/Air Telecommunications/...
Seyyed Ali Saadatdar Arani; Mehran Nosratollahi
Articles in Press, Accepted Manuscript, Available Online from 12 March 2023
Abstract
Studies are currently being conducted around the world to realize advanced air Mobility. Advanced Air Mobility is expected to solve various regional issues and provide people with new forms of air transportation. In this article, air travel is investigated as a significant option for improving transportation ...
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Studies are currently being conducted around the world to realize advanced air Mobility. Advanced Air Mobility is expected to solve various regional issues and provide people with new forms of air transportation. In this article, air travel is investigated as a significant option for improving transportation networks within and between different cities and regions in Iran, and Iran's market profile for accepting Advanced Air Mobility is investigated. Also, the challenges and issues facing Advanced Air Mobility have been studied, finally, some existing plans for use in various missions of Advanced Air Mobility and future mechanisms and plans for the realization and development of this field in Iran have been proposed.
Science and Technology
Structure/Solid Mechanics/Solid Dynamics/Vibrations/Aeroelasticity/...
Ehsan Raeisi Estabragh
Articles in Press, Accepted Manuscript, Available Online from 12 March 2023
Abstract
In the present study, the large deflection of nanobeams with surface effects has been investigated. The surface effects are modeled by using the generalized Young–Laplace equation. The finite element method has been used to investigate the mechanical behavior of nanobeams. This method provides ...
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In the present study, the large deflection of nanobeams with surface effects has been investigated. The surface effects are modeled by using the generalized Young–Laplace equation. The finite element method has been used to investigate the mechanical behavior of nanobeams. This method provides the possibility of solving the problem with the least assumptions and with the arbitrary boundary conditions and geometry. With the use of the proposed model, nanobeams small to large deflection with different loading and support conditions can be analyzed. In this study, the large deflection of circular cross-sectional nanobeams under sinusoidal distributed load with surface effects has been investigated. The effect of various parameters such as aspect ratio, surface elastic modulus and residual surface stress on the large deflection of nanobeams has been investigated. The result obtained show the importance of considering the surface effects in the study of large deflection of nanobeams.
Scientific extention
Structure/Solid Mechanics/Solid Dynamics/Vibrations/Aeroelasticity/...
S. Javid Mirahmadi; Mohamad Reza Nasresfahani
Articles in Press, Accepted Manuscript, Available Online from 12 March 2023
Abstract
Supplying the energy demanded by spacecraft and satellites is an ever-increasing need. As a result, it is an active field in developing space technologies. In addition to the commonly used rigid substrate solar arrays, flexible substrate and concentrator solar arrays are other available categories. This ...
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Supplying the energy demanded by spacecraft and satellites is an ever-increasing need. As a result, it is an active field in developing space technologies. In addition to the commonly used rigid substrate solar arrays, flexible substrate and concentrator solar arrays are other available categories. This paper reviewed the developments and commercial technologies in each category. The flexible solar arrays, implemented in several spacecraft during the last two decades, have recently attracted attention in satellites. It seems that these arrays will replace rigid arrays in the near term due to their higher specific power and smaller stow volume than rigid arrays.
Science and Technology
Structure/Solid Mechanics/Solid Dynamics/Vibrations/Aeroelasticity/...
hossein torabian; Simin kamali rousta; mohammad Jelokhani Niaraki
Articles in Press, Accepted Manuscript, Available Online from 13 March 2023
Abstract
According to friction stir processing For production of surface composites with constant progress and rotational speed, samples are made in different number of passes (1,3.5) and to obtain the stress range and adjust the device and apply the fatigue and tensile test is performed. Results of micro-structure ...
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According to friction stir processing For production of surface composites with constant progress and rotational speed, samples are made in different number of passes (1,3.5) and to obtain the stress range and adjust the device and apply the fatigue and tensile test is performed. Results of micro-structure study showed that with increasing number of passes, the distribution of underlying particles is improved, and maximum yield strength is for one sample and three samples have the longest Hight cycle life fatigue. The goal is improve the metal micro-structure with the new friction stirring technique, result shown the strength of the metal is improved, and resistance to wear, fatigue and corrosion is increased, it causes improvement of form-ability, which results increase in the number of The pass has led to a homogeneous and uniform distribution of reinforcing particles, in fact, increasing the number of passes in the process has led to a better distribution and separation of silicon-carbide particles in ground phase.
Science and Technology
Flight mechanics/Navigation/Control/...
Fatemeh Ghaderi; Alireza Toloei; Reza Ghasemi
Articles in Press, Accepted Manuscript, Available Online from 03 April 2023
Abstract
This article aims to control the group flight of unmanned helicopters. After presenting the dynamic equations using the Newton-Euler method, the dynamic inversion control has been applied to control the position and attitude of helicopters. generalized predictive control was also used to control the ...
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This article aims to control the group flight of unmanned helicopters. After presenting the dynamic equations using the Newton-Euler method, the dynamic inversion control has been applied to control the position and attitude of helicopters. generalized predictive control was also used to control the position and attitude of the helicopter. And the results of the simulation of these two controllers were compared, which showed the better performance of the predictive control. Therefore, in the design of the formation control, the independent control of the helicopters was done using the predictive control method. To control the formation, the method based on the leader-follower model has been used, An integral sliding mode controller is also used to control the dynamics of the formation error. The results of the simulation showed the success of the tracking by increasing the number of helicopters and the linear and spiral paths in the control commands.
Science and Technology
Flight mechanics/Navigation/Control/...
Mana Ghanifar; Milad Kamzan; Morteza Tayefi
Articles in Press, Accepted Manuscript, Available Online from 04 April 2023
Abstract
n this paper, the use of PID controller to control a model of a quadrotor with nonlinear dynamics is investigated. In this regard, after presenting the designed nonlinear dynamic quadrotor model, four distinct methods for adjusting the parameters of this controller are examined and compared. These four ...
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n this paper, the use of PID controller to control a model of a quadrotor with nonlinear dynamics is investigated. In this regard, after presenting the designed nonlinear dynamic quadrotor model, four distinct methods for adjusting the parameters of this controller are examined and compared. These four techniques, which are classified into two categories, online and offline, include online techniques of neural network and fuzzy inference, and offline techniques of genetic and particle swarm optimization algorithms. Finally according to the results of numerical simulations and the results of comparing a predefined squared cost function calculated in each case, in the presence of a relatively large disturbance with amplitude and frequency that is selected in the whole time simulation affects the system, shown in general, the order online algorithms, especially despite the mentioned disturbance, have better performance in controlling the dynamics of the system because they update the control coefficients of the closed-loop system momentarily in each step of numerical simulation.
Science and Technology
Design/System/Reliability/Flight Competence/Flight Testing/...
Mohammad Ali Farsi
Articles in Press, Accepted Manuscript, Available Online from 09 April 2023
Abstract
The success of missions and related costs has always been one of the concerns of researchers and due to the sensitivity and variety of missions, this issue is more important today. In the past decade, group fly is more investigated because of their influence on the quantity and quality of missions. ...
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The success of missions and related costs has always been one of the concerns of researchers and due to the sensitivity and variety of missions, this issue is more important today. In the past decade, group fly is more investigated because of their influence on the quantity and quality of missions. In this research, an Unmanned Air Vehicle (UAV) system that includes several UAVs that has a parallel structure and able to perform different missions to detect, follow and attack, has been considered. The UAV success rate is be defined according to the UAV conditions, the amount of failure, and the type of failure. it is assumed that its failure rate is not constant and has multistate behavior, also It has the ability to perform different operations assigned randomly, Universal generation function, and Markov chain methods for modeling are be developed. A UAV system has been considered and, the ability and accuracy of these methods are be demonstrated.
Science and Technology
Flight mechanics/Navigation/Control/...
Mohammad Hosein Alizadeh; Alireza Toloei
Articles in Press, Accepted Manuscript, Available Online from 15 April 2023
Abstract
The intended aircraft in this issue is an UAV type, capable of performing multiple missions. In this paper, after the linearization of the pitch channel, the transfer function for important points is extracted. After that, a robust classic compensator and an angular velocity damper are designed. According ...
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The intended aircraft in this issue is an UAV type, capable of performing multiple missions. In this paper, after the linearization of the pitch channel, the transfer function for important points is extracted. After that, a robust classic compensator and an angular velocity damper are designed. According to the range of uncertainties, the compensator is adjusted by article bee colony algorithm. Also, the optimal value of the wing sweep back angle is obtained indirectly from the optimal value of the center of aerodynamic pressure. The optimization approach in this pepper is to make pitch channel robust to uncertainties. The results show that with the innovation in the design of the classic controller and its combination with Mont Carlo simulation and Optimization algorithm, the behavior of the pitch channel in the presence of uncertainties has been improved.
Science and Technology
Structure/Solid Mechanics/Solid Dynamics/Vibrations/Aeroelasticity/...
Ali Davar; Mohsen Heydari Beni; Reza Azarafza; Jafar Eskandari Jam
Articles in Press, Accepted Manuscript, Available Online from 15 April 2023
Abstract
In this research, by improving the accuracy of existing high-order theories, a new corrected high-order composite cylindrical shell theory with twelve displacement components has been developed. In this theory, the effect of terms related to the trapezoidal shape of the shell cross-section (1+z/R) in ...
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In this research, by improving the accuracy of existing high-order theories, a new corrected high-order composite cylindrical shell theory with twelve displacement components has been developed. In this theory, the effect of terms related to the trapezoidal shape of the shell cross-section (1+z/R) in the results of the shell stress has been accurately calculated. After adding the strain energy such as the initial stresses and the strain energy such as the prevention of the rotation of the rigid body to the shell energy functional, based on Hamilton's principle, the equilibrium equations of the cylindrical shell with two ends have been derived. By using these equations, eigenvalue analysis (free vibrations) have been performed. Validation of the results of the present research was done by comparing with the theoretical and experimental results of other researchers and the results of the ABAQUS software, and a good match has been achieved.
Science and Technology
Aerodynamics/Fluid Mechanics/Aeroacoustics/...
Ramin Zakeri
Articles in Press, Accepted Manuscript, Available Online from 06 May 2023
Abstract
In this article, the deformable structures of a symmetrical airfoil and the discussion of aerodynamic forces are discussed inside the wind tunnel with miniature dimensions. The problem, which is checked in this article, is the investigation the effect of surface deformation in a small airfoil. In order ...
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In this article, the deformable structures of a symmetrical airfoil and the discussion of aerodynamic forces are discussed inside the wind tunnel with miniature dimensions. The problem, which is checked in this article, is the investigation the effect of surface deformation in a small airfoil. In order to validate the tunnel, a flat plate is examined in the miniature wind tunnel test section and the experimental results are reported with the existing results with an error of less than 10%. The selected sample of airfoils is one of simple small airfoils and another example is smart . The selected structure material for both small airfoil samples is balsa wood and thermal coating is used for the shell. The test section is analyzed and investigated with simple small airfoil. The next step include the design, fabrication, and finally, the evaluation of the smart small airfoil in the test section.
Scientific extention
Space Engineering/Space Orbit Mechanics/Space Sciences/...
Morteza Farhid; Samira Mir Mazhari Anvar; Moharram Shameli; Hossain Beheshti birami
Articles in Press, Accepted Manuscript, Available Online from 21 May 2023
Abstract
This paper discusses how to implement the CAN bus protocol based on the ECSS standard in the space applications of satellites and various missions. The CAN protocol frame consists of the frameworks, arbitration and control, data, cyclic redundancy, and verification sections. The arbitration and control ...
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This paper discusses how to implement the CAN bus protocol based on the ECSS standard in the space applications of satellites and various missions. The CAN protocol frame consists of the frameworks, arbitration and control, data, cyclic redundancy, and verification sections. The arbitration and control section are responsible for controlling the data flow. There are two standards for these two parts, which satellites usually use the developed CAN standard according to which the LDUT protocol is designed, due to the need to use the LDUT protocol for big data transmission. Also, to manage the redundancy of the CAN bus, the implementation conditions of the parameters of each node will be checked. Also, this protocol is implemented on the reaction wheel condition with microcontroller hardware and related converter considerations in MPLAB software environment and is approved by Microchip Analyzer CAN separately and OBC simulator as a quadruple group with the correct function of the approved bus redundancy.
Science and Technology
Propulsion/Thermodynamics/Heat Transfer/Fuel and Combustion/Energy/...
Mohsen Esfandi; Mohammad Kazem Moayyedi
Articles in Press, Accepted Manuscript, Available Online from 09 June 2023
Abstract
In this study, the simulation of internal ballistics and the exhaust flow of a solid propellant engine have been investigated. The flow field considered in this problem including the cylindrical grain and the solid wall of the engine and the flow at the nozzle outlet have been studied. The governing ...
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In this study, the simulation of internal ballistics and the exhaust flow of a solid propellant engine have been investigated. The flow field considered in this problem including the cylindrical grain and the solid wall of the engine and the flow at the nozzle outlet have been studied. The governing equations are used in an axisymmetric and compressible form to model the fuel combustion in non-erosive combustion mode. In the present study, cylindrical type of grain fuel is considered, which is one of the most useful types of fuel grains in terms of simplicity in production. In order to obtain the results from the simulation model which are close to the real data, used UDF modules in the Fluent software to describe some specific quantities and phenomena of the problem. Finally, the results obtained from the simulation in different modes of fuel burning are examined and show the accuracy of the numerical model by entering the parameters affecting the fuel burning.
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