Science Publishing Group: American Journal of Aerospace Engineering: Table of Contents
<i>American Journal of Aerospace Engineering (AJAE) </i> is a peer-reviewed open access journal published bimonthly in English-language, providing a broad coverage of the materials and techniques employed in the aircraft and aerospace industry. This journal publishes original papers, review articles and short communications, including two major and overlapping branches: aeronautical engineering and astronautical engineering. The former deals with aircraft that operate in Earth's atmosphere, and the latter with spacecraft that operate outside it.
http://www.sciencepublishinggroup.com/j/ajae Science Publishing Group: American Journal of Aerospace Engineering: Table of Contents
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American Journal of Aerospace Engineering
American Journal of Aerospace Engineering
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Robust PID Controller Design for a Modern Type Aircraft Including Handling Quality Evaluation
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140101.11
In this paper we present classical PID controller approach in designing longitudinal Stability Augmentation System and pitch attitude control (SCAS) at nonlinear flight region for a high fidelity F-16 model including aerodynamic uncertainty. In high angle of attack, nonlinear effects of aerodynamic coefficients and atmospheric turbulence are the main challenge in designing and robustness of flight control system. A design scenario that combines deadbeat response and robust control (aerodynamic uncertainties and atmospheric turbulence) is presented. Simulation results show that the designed PI controller exhibits robustness property to system uncertainties.
In this paper we present classical PID controller approach in designing longitudinal Stability Augmentation System and pitch attitude control (SCAS) at nonlinear flight region for a high fidelity F-16 model including aerodynamic uncertainty. In high angle of attack, nonlinear effects of aerodynamic coefficients and atmospheric turbulence are the main challenge in designing and robustness of flight control system. A design scenario that combines deadbeat response and robust control (aerodynamic uncertainties and atmospheric turbulence) is presented. Simulation results show that the designed PI controller exhibits robustness property to system uncertainties.
Robust PID Controller Design for a Modern Type Aircraft Including Handling Quality Evaluation
doi:10.11648/j.ajae.20140101.11
American Journal of Aerospace Engineering
2014-01-01
© Science Publishing Group
Mohammad Salem
Mohammad Ali Shahi Ashtiani
Robust PID Controller Design for a Modern Type Aircraft Including Handling Quality Evaluation
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7
2014-01-01
2014-01-01
10.11648/j.ajae.20140101.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140101.11
© Science Publishing Group
Application of Response Surface Methodology during Conceptual Design for Mission Analysis
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The design of complex engineering problems requires computation of several optimal parameters that is generally very time consuming and computationally expensive process. When using computationally expensive simulation programs/algorithms in engineering design for optimization, sometimes it becomes impractical to rely exclusively on simulation codes only. This study involved the designing of a suitable metamodel by using Kriging response surfaces which will be used for global optimization purposes. The study also covers the implementation of Kriging mathematical model in the form of a computer algorithm which is written in MATLAB.
The design of complex engineering problems requires computation of several optimal parameters that is generally very time consuming and computationally expensive process. When using computationally expensive simulation programs/algorithms in engineering design for optimization, sometimes it becomes impractical to rely exclusively on simulation codes only. This study involved the designing of a suitable metamodel by using Kriging response surfaces which will be used for global optimization purposes. The study also covers the implementation of Kriging mathematical model in the form of a computer algorithm which is written in MATLAB.
Application of Response Surface Methodology during Conceptual Design for Mission Analysis
doi:10.11648/j.ajae.20140102.11
American Journal of Aerospace Engineering
2014-07-16
© Science Publishing Group
Johar Daudi
Application of Response Surface Methodology during Conceptual Design for Mission Analysis
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2
15
15
2014-07-16
2014-07-16
10.11648/j.ajae.20140102.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140102.11
© Science Publishing Group
High-Efficiency Mission Planning and Distribution System of the Land Observation Satellites
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140103.11
The mission planning of earth satellite observation generally refers to the optimized use of satellites' payloads. According to relevant experiences in project construction, this paper puts forth the concept of the integrated hub-style mission planning on the basis of consumers' satisfaction and data's timeliness. This concept takes the ground processing center as the integrated service point, and data demands of difference levels of users as the driving force. It fully considers the practical problems like station resources construction lag and data transmission link frequency interference conflicts, reasonably plan the satellite payloads data reception stations resources, monitor and control resources and data processing resources, so as to implement the remote sensing data from a data request, overall planning, telecontrol, data acquisition, data processing and the unified distribution in the whole process of mission planning model. This model effectively solves the problems like the difficulty to match single satellite programming model with user demands, and the low efficiency of resource use. Besides, the paper seeks to explore relevant elements, technology and techniques which are necessary in such mission planning. The author thinks that from the vintage point of systems engineering, the commercialization of satellite observation products requires the full-cycle integrated mission planning that covers the period from the beginning of a user's order to the distribution of final data products, among which dispatching satellites' payloads is only one of important links. During the cycle, activities and constraints related to land support systems and other elements should also be taken into consideration. The comprehensive consideration including points of data acquisition, processing, archiving and distribution will make mission planning more complicated, which needs to be studied theoretically and practically. The full-cycle and integrated hub-style mission planning coordinates with national policy of civil remote sensing satellites. It is of great significance to deliver remote sensing products with high quality and high timeliness to every professional user through remote sensing data planning and major processing points, which demonstrates in two aspects. The first aspect is that it helps to achieve the win-win situation where different users get what they want and the state reduces investment in this field. The other one is that it is facile to monitor various satellite data and in return promote technology advancement of satellite processing and construction, which eventually stimulates the development and progress of aerospace remote sensing technology.
The mission planning of earth satellite observation generally refers to the optimized use of satellites' payloads. According to relevant experiences in project construction, this paper puts forth the concept of the integrated hub-style mission planning on the basis of consumers' satisfaction and data's timeliness. This concept takes the ground processing center as the integrated service point, and data demands of difference levels of users as the driving force. It fully considers the practical problems like station resources construction lag and data transmission link frequency interference conflicts, reasonably plan the satellite payloads data reception stations resources, monitor and control resources and data processing resources, so as to implement the remote sensing data from a data request, overall planning, telecontrol, data acquisition, data processing and the unified distribution in the whole process of mission planning model. This model effectively solves the problems like the difficulty to match single satellite programming model with user demands, and the low efficiency of resource use. Besides, the paper seeks to explore relevant elements, technology and techniques which are necessary in such mission planning. The author thinks that from the vintage point of systems engineering, the commercialization of satellite observation products requires the full-cycle integrated mission planning that covers the period from the beginning of a user's order to the distribution of final data products, among which dispatching satellites' payloads is only one of important links. During the cycle, activities and constraints related to land support systems and other elements should also be taken into consideration. The comprehensive consideration including points of data acquisition, processing, archiving and distribution will make mission planning more complicated, which needs to be studied theoretically and practically. The full-cycle and integrated hub-style mission planning coordinates with national policy of civil remote sensing satellites. It is of great significance to deliver remote sensing products with high quality and high timeliness to every professional user through remote sensing data planning and major processing points, which demonstrates in two aspects. The first aspect is that it helps to achieve the win-win situation where different users get what they want and the state reduces investment in this field. The other one is that it is facile to monitor various satellite data and in return promote technology advancement of satellite processing and construction, which eventually stimulates the development and progress of aerospace remote sensing technology.
High-Efficiency Mission Planning and Distribution System of the Land Observation Satellites
doi:10.11648/j.ajae.20140103.11
American Journal of Aerospace Engineering
2014-10-24
© Science Publishing Group
Qiu Hu
High-Efficiency Mission Planning and Distribution System of the Land Observation Satellites
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2014-10-24
2014-10-24
10.11648/j.ajae.20140103.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140103.11
© Science Publishing Group
Tele-Operated Robotic Arm and Hand with Intuitive Control and Haptic Feedback
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140104.11
The paper presents a robotic arm having as end effector an anthropomorphic hand and its control system. The robotic arm and hand are controlled using a Complex Interactive Control Glove (CICG) and operator joint sensors. The robotic hand imitates the finger and joint movements of the human operator. The anthropomorphic hand sends pressure feedback from a pressure sensor array mounted at the robotic hand’s fingers and palm to the human operator wearing a Complex Interactive Control Glove that comprises haptic actuators. The pressure exerted by the robotic hand on various objects is perceived as vibrations on the corresponding hand area of the human operator. The robotic arm adjusts its position in correlation with the human operator’s arm, placing the end effector at the right position, corresponding to the operator’s hand. Data for the movement of the robotic arm are collected from the movements of the human operator by means of three joint sensors placed on the shoulder, elbow and hand wrist. Targeted applications of the tele-operated robotic arm and hand with intuitive control and haptic feedback include all situations where a human-like operation is needed in a hazardous or remote environment: space environment, operations executed in toxic atmosphere, working in high-radiation level environments, marine applications. In such cases, the robotic hand and arm that are executing the same movements as the human operator can replace the actual human operator. This will control the robotic arm form a safe, possibly remote, environment, and will be able to process the haptic feedback of the systems.
The paper presents a robotic arm having as end effector an anthropomorphic hand and its control system. The robotic arm and hand are controlled using a Complex Interactive Control Glove (CICG) and operator joint sensors. The robotic hand imitates the finger and joint movements of the human operator. The anthropomorphic hand sends pressure feedback from a pressure sensor array mounted at the robotic hand’s fingers and palm to the human operator wearing a Complex Interactive Control Glove that comprises haptic actuators. The pressure exerted by the robotic hand on various objects is perceived as vibrations on the corresponding hand area of the human operator. The robotic arm adjusts its position in correlation with the human operator’s arm, placing the end effector at the right position, corresponding to the operator’s hand. Data for the movement of the robotic arm are collected from the movements of the human operator by means of three joint sensors placed on the shoulder, elbow and hand wrist. Targeted applications of the tele-operated robotic arm and hand with intuitive control and haptic feedback include all situations where a human-like operation is needed in a hazardous or remote environment: space environment, operations executed in toxic atmosphere, working in high-radiation level environments, marine applications. In such cases, the robotic hand and arm that are executing the same movements as the human operator can replace the actual human operator. This will control the robotic arm form a safe, possibly remote, environment, and will be able to process the haptic feedback of the systems.
Tele-Operated Robotic Arm and Hand with Intuitive Control and Haptic Feedback
doi:10.11648/j.ajae.20140104.11
American Journal of Aerospace Engineering
2014-12-22
© Science Publishing Group
Monica Dascalu
Mihail Stefan Teodorescu
Anca Plavitu
Lucian Milea
Eduard Franti
Dan Coroama
Doina Moraru
Tele-Operated Robotic Arm and Hand with Intuitive Control and Haptic Feedback
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27
27
2014-12-22
2014-12-22
10.11648/j.ajae.20140104.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20140104.11
© Science Publishing Group
CubeSail Displaced Orbit Design for Near Earth Object Observation
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20150201.11
Microsatellites known as “CubeSats” have recently been developed to enable comparatively inexpensive and timely access to space for small payloads. As a new standard for small satellites, the CubeSat has shown great promise for space applications such as earth observation, planetary science and space physics mission. In this paper a “CubeSail” mission – a CubeSat deployed with a solar sail –for near earth object (NEO) observation is introduced. It is important to observe a NEO which may intersect or pass close to earth space before instigating any procedure for hazard avoidance. Furthermore, close observation of NEO may also be important for exploiting the new resources and exploring new living environment in outer space. This paper describes the concept of a large numbers of CubeSails deployed in the vicinity of the NEO for observation purposes. The dynamic model of the NEO-centreddis placed orbit in space is analysed. The solar radiation pressure on the sail can be utilised as propulsion to compensate for third body gravitational perturbation. To maintain the relative motion/position between a CubeSail and the NEO, periodic initial conditions are searched, which also must satisfy some observation mission constraints. A simulation study is carried out using the near earth asteroid Apophis 99942, discovered in recent years.
Microsatellites known as “CubeSats” have recently been developed to enable comparatively inexpensive and timely access to space for small payloads. As a new standard for small satellites, the CubeSat has shown great promise for space applications such as earth observation, planetary science and space physics mission. In this paper a “CubeSail” mission – a CubeSat deployed with a solar sail –for near earth object (NEO) observation is introduced. It is important to observe a NEO which may intersect or pass close to earth space before instigating any procedure for hazard avoidance. Furthermore, close observation of NEO may also be important for exploiting the new resources and exploring new living environment in outer space. This paper describes the concept of a large numbers of CubeSails deployed in the vicinity of the NEO for observation purposes. The dynamic model of the NEO-centreddis placed orbit in space is analysed. The solar radiation pressure on the sail can be utilised as propulsion to compensate for third body gravitational perturbation. To maintain the relative motion/position between a CubeSail and the NEO, periodic initial conditions are searched, which also must satisfy some observation mission constraints. A simulation study is carried out using the near earth asteroid Apophis 99942, discovered in recent years.
CubeSail Displaced Orbit Design for Near Earth Object Observation
doi:10.11648/j.ajae.20150201.11
American Journal of Aerospace Engineering
2015-04-20
© Science Publishing Group
Yang Yang
Xiaokui Yue
Yong Li
Andrew G. Dempster
Chris. Rizos
CubeSail Displaced Orbit Design for Near Earth Object Observation
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1
5
5
2015-04-20
2015-04-20
10.11648/j.ajae.20150201.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.20150201.11
© Science Publishing Group
Numerical Solution of Solar Energy Absorbed in Porous Medium with a New Approach for Vapor Pressure Calculation and Consideration of Solute Crystallization
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.18
The goal of the study is to enhance the productivity of solar stills using an unsaturated porous medium initially saturated by salty water and using concentrating reflector. This paper concentrates only on the mathematical model for the porous medium and its solution using a finite-volume approach. The previous studies dealt with wick medium with high water content and liquid saturation in the wick medium was not determined. A physical model for the initially saturated porous medium was developed. The model takes into consideration the salt concentration in the solution, surface and internal water diffusions to humid air with vapor pressure determined from vapor mass balance. The system of transient one-dimensional differential equations was developed together with the boundaries and initial conditions. A finite-volume method was used for discretisation of the differential equations. A fully-implicit scheme was used for unsteady term discretisation while the convective terms (liquid solution, vapor and dry air) in the energy equation are handled by an upwind scheme method. The nonlinear equations are solved simultaneously by updating the coefficients matrix at one time step until the five variables converge to prescribed tolerance. Matlab was used as a programming tool. Solution of the model is obtained and discussed.
The goal of the study is to enhance the productivity of solar stills using an unsaturated porous medium initially saturated by salty water and using concentrating reflector. This paper concentrates only on the mathematical model for the porous medium and its solution using a finite-volume approach. The previous studies dealt with wick medium with high water content and liquid saturation in the wick medium was not determined. A physical model for the initially saturated porous medium was developed. The model takes into consideration the salt concentration in the solution, surface and internal water diffusions to humid air with vapor pressure determined from vapor mass balance. The system of transient one-dimensional differential equations was developed together with the boundaries and initial conditions. A finite-volume method was used for discretisation of the differential equations. A fully-implicit scheme was used for unsteady term discretisation while the convective terms (liquid solution, vapor and dry air) in the energy equation are handled by an upwind scheme method. The nonlinear equations are solved simultaneously by updating the coefficients matrix at one time step until the five variables converge to prescribed tolerance. Matlab was used as a programming tool. Solution of the model is obtained and discussed.
Numerical Solution of Solar Energy Absorbed in Porous Medium with a New Approach for Vapor Pressure Calculation and Consideration of Solute Crystallization
doi:10.11648/j.ajae.s.2015020101.18
American Journal of Aerospace Engineering
2014-11-25
© Science Publishing Group
Sherif A. Mohamed
Ibrahim S. Taha
Mahmoud G. Morsy
Hany A. Mohamed
Mahmoud S. Ahmed
Numerical Solution of Solar Energy Absorbed in Porous Medium with a New Approach for Vapor Pressure Calculation and Consideration of Solute Crystallization
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105
2014-11-25
2014-11-25
10.11648/j.ajae.s.2015020101.18
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.18
© Science Publishing Group
Erosion of an Axial Transonic Fan due to Dust Ingestion
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.15
This paper deals with the prediction of the particle dynamic and erosion characteristics due to dust ingestion in an axial flow fan, installed in a high bypass-ratio turbofan engine that operates in a dusty environment. Dynamic behavior comprises the particle trajectory and its impact velocity and location. While the erosion characteristics are resembled by the impact frequency, erosion rate, erosion parameter and the penetration rate. The study was carried out in two flight regimes, namely, takeoff, where the sand particles are prevailing, and cruise, where the fly ashes are dominated. In both cases, the effect of the particle size on its trajectory, impact location, and the erosion characteristics was studied. To simulate the problem in a more realistic manner, a Rosin Rambler particle diameter distribution was assumed at takeoff and cruise conditions. At takeoff, this distribution varies from 50 to 300 μm with a mean diameter of 150 μm sand particles. While at cruise, this distribution varies from 5 to 30 μm with a mean diameter of 15 μm fly ash particles. The computational domain employed was a periodic sector through both the fan and its intake bounding an angle of (360/38) where the number of fan blades is (38). The intake is a stationary domain while the fan is a rotating one and the FLUENT solver is used to solve this problem. Firstly, the flow field was solved in the computational domain using the Navier-Stokes finite- volume supported by the Spalart-Allmaras turbulence model. The governing equations, representing the particle motion through the moving stream of a compressible flow are introduced herein to calculate the particle trajectory. The solution of these equations is carried out based on the Lagrangian approach. Next, empirical equations representing the particle impact characteristics with the walls are introduced to calculate the rebound velocity, the erosion rate, erosion parameter, impact frequency and penetration rate. Moreover, a method to smoothen the irregularity in the calculated scattered data was discussed as well. During takeoff flight regime, the pressure side of fan blade experienced higher particle impact and erosion damage. The highest erosion rate was found at the corner formed by blade tip and trailing edge of pressure side. During cruise conditions, less erosion rates resulted. Maximum erosion rates are found at the leading edge of the pressure side.
This paper deals with the prediction of the particle dynamic and erosion characteristics due to dust ingestion in an axial flow fan, installed in a high bypass-ratio turbofan engine that operates in a dusty environment. Dynamic behavior comprises the particle trajectory and its impact velocity and location. While the erosion characteristics are resembled by the impact frequency, erosion rate, erosion parameter and the penetration rate. The study was carried out in two flight regimes, namely, takeoff, where the sand particles are prevailing, and cruise, where the fly ashes are dominated. In both cases, the effect of the particle size on its trajectory, impact location, and the erosion characteristics was studied. To simulate the problem in a more realistic manner, a Rosin Rambler particle diameter distribution was assumed at takeoff and cruise conditions. At takeoff, this distribution varies from 50 to 300 μm with a mean diameter of 150 μm sand particles. While at cruise, this distribution varies from 5 to 30 μm with a mean diameter of 15 μm fly ash particles. The computational domain employed was a periodic sector through both the fan and its intake bounding an angle of (360/38) where the number of fan blades is (38). The intake is a stationary domain while the fan is a rotating one and the FLUENT solver is used to solve this problem. Firstly, the flow field was solved in the computational domain using the Navier-Stokes finite- volume supported by the Spalart-Allmaras turbulence model. The governing equations, representing the particle motion through the moving stream of a compressible flow are introduced herein to calculate the particle trajectory. The solution of these equations is carried out based on the Lagrangian approach. Next, empirical equations representing the particle impact characteristics with the walls are introduced to calculate the rebound velocity, the erosion rate, erosion parameter, impact frequency and penetration rate. Moreover, a method to smoothen the irregularity in the calculated scattered data was discussed as well. During takeoff flight regime, the pressure side of fan blade experienced higher particle impact and erosion damage. The highest erosion rate was found at the corner formed by blade tip and trailing edge of pressure side. During cruise conditions, less erosion rates resulted. Maximum erosion rates are found at the leading edge of the pressure side.
Erosion of an Axial Transonic Fan due to Dust Ingestion
doi:10.11648/j.ajae.s.2015020101.15
American Journal of Aerospace Engineering
2014-10-16
© Science Publishing Group
Ahmed Fayez EL-Saied
Mohamed Hassan Gobran
Hassan Zohier Hassan
Erosion of an Axial Transonic Fan due to Dust Ingestion
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1
63
63
2014-10-16
2014-10-16
10.11648/j.ajae.s.2015020101.15
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.15
© Science Publishing Group
CFD Modeling of the Atmospheric Boundary Layer in Short Test Section Wind Tunnel
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.14
The aim of this paper is to provide a contribution to algorithms for the numerical simulation of the atmospheric boundary layer (ABL) in short test section wind tunnel, with the lowest pressure loss possible, for large Re, similar to the high values observed in nature. Different turbulent models have been examined for their relative suitability for the atmospheric boundary layer airflow with and without the implementation of buoyancy effects with modified turbulence model constants for the atmosphere. Validation of turbulent models through comparison with wind tunnel experiments is essential for practical applications. It has been observed that the k-ε model is most suitable tool for generation of an ABL in short-chamber wind tunnel. A comparison has been made with the available experimental data, from literature, and the predicted CFD values are very close to the corresponding experimental measurements. The simulation results show the importance of turbulence model constant (Cµ), the non-uniform velocity and turbulence intensity profiles. Also, the significance of y+ for consistent assessment is confirmed. However, it has been found that the buoyancy force makes significant change in boundary layer thickness without a major impact on computation time.
The aim of this paper is to provide a contribution to algorithms for the numerical simulation of the atmospheric boundary layer (ABL) in short test section wind tunnel, with the lowest pressure loss possible, for large Re, similar to the high values observed in nature. Different turbulent models have been examined for their relative suitability for the atmospheric boundary layer airflow with and without the implementation of buoyancy effects with modified turbulence model constants for the atmosphere. Validation of turbulent models through comparison with wind tunnel experiments is essential for practical applications. It has been observed that the k-ε model is most suitable tool for generation of an ABL in short-chamber wind tunnel. A comparison has been made with the available experimental data, from literature, and the predicted CFD values are very close to the corresponding experimental measurements. The simulation results show the importance of turbulence model constant (Cµ), the non-uniform velocity and turbulence intensity profiles. Also, the significance of y+ for consistent assessment is confirmed. However, it has been found that the buoyancy force makes significant change in boundary layer thickness without a major impact on computation time.
CFD Modeling of the Atmospheric Boundary Layer in Short Test Section Wind Tunnel
doi:10.11648/j.ajae.s.2015020101.14
American Journal of Aerospace Engineering
2014-10-16
© Science Publishing Group
Yassen El-Sayed Yassen
Ahmed Sharaf Abdelhamed
CFD Modeling of the Atmospheric Boundary Layer in Short Test Section Wind Tunnel
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46
46
2014-10-16
2014-10-16
10.11648/j.ajae.s.2015020101.14
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.14
© Science Publishing Group
Performance Evaluation of the Tandem C4 Blades for Axial-Flow Compressors
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.17
The purpose of this work is to study the aerodynamic performance of a tandem C4 base-profile compressor blade using numerical tools. In this paper, the flow along the tandem blade is studied for various relative blade positions. In all the studied cases, the front blade is fixed and the position of the rear blade is varied as a function of the axial and tangential displacements. A computer code was developed in "Visual Basic" using linear strength vortex-panel method to predict the aerodynamic performance of the tandem blade.
The purpose of this work is to study the aerodynamic performance of a tandem C4 base-profile compressor blade using numerical tools. In this paper, the flow along the tandem blade is studied for various relative blade positions. In all the studied cases, the front blade is fixed and the position of the rear blade is varied as a function of the axial and tangential displacements. A computer code was developed in "Visual Basic" using linear strength vortex-panel method to predict the aerodynamic performance of the tandem blade.
Performance Evaluation of the Tandem C4 Blades for Axial-Flow Compressors
doi:10.11648/j.ajae.s.2015020101.17
American Journal of Aerospace Engineering
2014-10-17
© Science Publishing Group
Atef Mohamed Alm-Eldien
Ahmed Farouk Abdel Gawad
Gamal Hafaz
Mohamed Gaber Abd El Kreim
Performance Evaluation of the Tandem C4 Blades for Axial-Flow Compressors
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2014-10-17
2014-10-17
10.11648/j.ajae.s.2015020101.17
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.17
© Science Publishing Group
Computational Investigation of Aerodynamic Characteristics and Drag Reduction of a Bus Model
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.16
It is well-known that buses comprise an important part of mass transportation and that there are many types of buses. At present, the bus transportation is cheaper and easier to use than other means of transportation. However, buses have some disadvantages such as air pollution due to engine exhaust. This study is an attempt to reduce the gas emissions from buses by reducing the aerodynamic drag. Several ideas were applied to achieve this goal including slight modification of the outer shape of the bus. Thus, six different cases were investigated. A computational model was developed to conduct this study. It was found that reduction in aerodynamic drag up to 14% can be reached, which corresponds to 8.4 % reduction in fuel consumption. Also, Neuro-Fuzzy technique was used to predict the aerodynamic drag of the bus in different cases.
It is well-known that buses comprise an important part of mass transportation and that there are many types of buses. At present, the bus transportation is cheaper and easier to use than other means of transportation. However, buses have some disadvantages such as air pollution due to engine exhaust. This study is an attempt to reduce the gas emissions from buses by reducing the aerodynamic drag. Several ideas were applied to achieve this goal including slight modification of the outer shape of the bus. Thus, six different cases were investigated. A computational model was developed to conduct this study. It was found that reduction in aerodynamic drag up to 14% can be reached, which corresponds to 8.4 % reduction in fuel consumption. Also, Neuro-Fuzzy technique was used to predict the aerodynamic drag of the bus in different cases.
Computational Investigation of Aerodynamic Characteristics and Drag Reduction of a Bus Model
doi:10.11648/j.ajae.s.2015020101.16
American Journal of Aerospace Engineering
2014-10-16
© Science Publishing Group
Eyad Amen Mohamed
Muhammad Naeem Radhwi
Ahmed Farouk AbdelGawad
Computational Investigation of Aerodynamic Characteristics and Drag Reduction of a Bus Model
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73
73
2014-10-16
2014-10-16
10.11648/j.ajae.s.2015020101.16
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.16
© Science Publishing Group
Design of Mini Wind Tunnel Based on Coanda Effect
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.13
An experimental investigation and CFD treatment were employed to design mini-wind tunnel based on Coanda effect for model tests and basic research. The inlet source flow is efficiently creating smooth steady airflow with acceptable noise, achieving the possibility of placing the test target closer to the source of flow with reasonable estimates of turbulence intensity. The design aims at achieving flow uniformity in the working section midplane, preventing separation in the contraction and minimizing the boundary–layer thickness. Intensive measurements after construction demonstrate the significance of the design process and validate the CFD predictions. The results are represented in graphic form to indicate the aspects of the contraction ratio. The numerical and experimental results show the uniformity of velocity distribution inside the working section. Tracing of separation and backflow is crucial allowing a variety of realistic demonstrations to be performed. The numerical solution provides a powerful tool to demonstrate the rate of boundary–layer growth inside the working section and validate against the empirical correlations with insignificant wall–friction drag. Assessment study to address large–scale wind tunnel based on coanda effect would be considered.
An experimental investigation and CFD treatment were employed to design mini-wind tunnel based on Coanda effect for model tests and basic research. The inlet source flow is efficiently creating smooth steady airflow with acceptable noise, achieving the possibility of placing the test target closer to the source of flow with reasonable estimates of turbulence intensity. The design aims at achieving flow uniformity in the working section midplane, preventing separation in the contraction and minimizing the boundary–layer thickness. Intensive measurements after construction demonstrate the significance of the design process and validate the CFD predictions. The results are represented in graphic form to indicate the aspects of the contraction ratio. The numerical and experimental results show the uniformity of velocity distribution inside the working section. Tracing of separation and backflow is crucial allowing a variety of realistic demonstrations to be performed. The numerical solution provides a powerful tool to demonstrate the rate of boundary–layer growth inside the working section and validate against the empirical correlations with insignificant wall–friction drag. Assessment study to address large–scale wind tunnel based on coanda effect would be considered.
Design of Mini Wind Tunnel Based on Coanda Effect
doi:10.11648/j.ajae.s.2015020101.13
American Journal of Aerospace Engineering
2014-10-07
© Science Publishing Group
Yassen El-Sayed Yassen
Ahmed Sharaf Abdelhamed
Design of Mini Wind Tunnel Based on Coanda Effect
2
1
37
37
2014-10-07
2014-10-07
10.11648/j.ajae.s.2015020101.13
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.13
© Science Publishing Group
Proposed Simple Electro-Mechanical Automotive Speed Control System
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.11
Millions of people are killed or seriously injured on the roads due to terrified accidents every year. Most of these accidents are attributed to the over-speeding of the road vehicles. Thus, the road speed limiter (RSL) is a very important technique to reduce the possibility of road accidents. An interesting idea to control the speed of the vehicle is to apply electronic control of the air-supply that enters the vehicle carburetor according to road transmitters that are connected and operated either by local network or satellite. In the present paper, a control system was designed and implemented. It is consisted of a control mechanism and an electronic circuit to control the air-inlet to the carburetor according to pre-set programming based on the vehicle speed. Although, it is a challenging job to design and implement modifications to existing systems, the present speed control system was successfully implemented and tested. The present proposed mechanism is simple, inexpensive and suitable to be implemented in developing countries where a big number of cars still work using the traditional carburetor mechanism.
Millions of people are killed or seriously injured on the roads due to terrified accidents every year. Most of these accidents are attributed to the over-speeding of the road vehicles. Thus, the road speed limiter (RSL) is a very important technique to reduce the possibility of road accidents. An interesting idea to control the speed of the vehicle is to apply electronic control of the air-supply that enters the vehicle carburetor according to road transmitters that are connected and operated either by local network or satellite. In the present paper, a control system was designed and implemented. It is consisted of a control mechanism and an electronic circuit to control the air-inlet to the carburetor according to pre-set programming based on the vehicle speed. Although, it is a challenging job to design and implement modifications to existing systems, the present speed control system was successfully implemented and tested. The present proposed mechanism is simple, inexpensive and suitable to be implemented in developing countries where a big number of cars still work using the traditional carburetor mechanism.
Proposed Simple Electro-Mechanical Automotive Speed Control System
doi:10.11648/j.ajae.s.2015020101.11
American Journal of Aerospace Engineering
2014-10-07
© Science Publishing Group
Ahmed Farouk AbdelGawad
Talal Saleh Mandourah
Proposed Simple Electro-Mechanical Automotive Speed Control System
2
1
10
10
2014-10-07
2014-10-07
10.11648/j.ajae.s.2015020101.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.11
© Science Publishing Group
Hands-On Engineering Education by Construction and Testing of Models of Sailing Boats
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.12
This paper introduces involvement of the hands-on learning method. According to the modern environment of technology, engineering students have to realize the multidisciplinary nature of engineering systems. This learning technique is essential to offer students the necessary skills to master practical, organizational and work-group cleverness. The work is concerned with the redesign, construction and operation of two models of sailing boats. The approach of the work and final outputs are illustrated.
This paper introduces involvement of the hands-on learning method. According to the modern environment of technology, engineering students have to realize the multidisciplinary nature of engineering systems. This learning technique is essential to offer students the necessary skills to master practical, organizational and work-group cleverness. The work is concerned with the redesign, construction and operation of two models of sailing boats. The approach of the work and final outputs are illustrated.
Hands-On Engineering Education by Construction and Testing of Models of Sailing Boats
doi:10.11648/j.ajae.s.2015020101.12
American Journal of Aerospace Engineering
2014-10-07
© Science Publishing Group
Ahmed Farouk AbdelGawad
Hands-On Engineering Education by Construction and Testing of Models of Sailing Boats
2
1
30
30
2014-10-07
2014-10-07
10.11648/j.ajae.s.2015020101.12
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2015020101.12
© Science Publishing Group
Towards the Capabilities of Rocket Engines with Solar Heating of Working Fluid
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.11
The purpose of this research is to show the potentiality of the rocket with solar heating of working fluid. The study describes design of the heater with tungsten pipes, ensuring full-range application of focusing radiation (95 %) under the hydrogen heating to 2900 К; gives an examples of optimization of rocket engine thrust by the flight time with predetermined fuel weight and specific weight of engine with mirror and payload; illustrates design of the engine and mirrors providing the conjugation between the thrust vector and solar radiation vector; demonstrates design of power-supply source with high-efficient solar energy transformation into electric one and compares various types of the rockets.
The purpose of this research is to show the potentiality of the rocket with solar heating of working fluid. The study describes design of the heater with tungsten pipes, ensuring full-range application of focusing radiation (95 %) under the hydrogen heating to 2900 К; gives an examples of optimization of rocket engine thrust by the flight time with predetermined fuel weight and specific weight of engine with mirror and payload; illustrates design of the engine and mirrors providing the conjugation between the thrust vector and solar radiation vector; demonstrates design of power-supply source with high-efficient solar energy transformation into electric one and compares various types of the rockets.
Towards the Capabilities of Rocket Engines with Solar Heating of Working Fluid
doi:10.11648/j.ajae.s.2016030101.11
American Journal of Aerospace Engineering
2015-07-28
© Science Publishing Group
V. М. Kotov
Towards the Capabilities of Rocket Engines with Solar Heating of Working Fluid
3
1
5
5
2015-07-28
2015-07-28
10.11648/j.ajae.s.2016030101.11
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.11
© Science Publishing Group
The Techniques to Control a Space Laboratory Orbital Motion During Conducting of Gravity-sensitive Processes on Its Board
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.12
The following article deals with three different techniques to control orbital motion of spacecraft with big flexible structures during conducting of gravity-sensitive processes on its board. These processes require low level of microaccelerations. There were given examples of application of the techniques, recommendations for application of these techniques in practice, discussed advantages and disadvantages of each technique.
The following article deals with three different techniques to control orbital motion of spacecraft with big flexible structures during conducting of gravity-sensitive processes on its board. These processes require low level of microaccelerations. There were given examples of application of the techniques, recommendations for application of these techniques in practice, discussed advantages and disadvantages of each technique.
The Techniques to Control a Space Laboratory Orbital Motion During Conducting of Gravity-sensitive Processes on Its Board
doi:10.11648/j.ajae.s.2016030101.12
American Journal of Aerospace Engineering
2015-07-28
© Science Publishing Group
A. V. Sedelnikov
The Techniques to Control a Space Laboratory Orbital Motion During Conducting of Gravity-sensitive Processes on Its Board
3
1
9
9
2015-07-28
2015-07-28
10.11648/j.ajae.s.2016030101.12
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.12
© Science Publishing Group
Basic Development Stages of the Algorithms Applied to Recover Lost Microacceleration Data and Check Efficiency of Measuring Equipment on the Board of Space Laboratory
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.13
The following article deals with the algorithm applied to recover lost microacceleration data. The algorithm allows recovering on the basis of available part of measuring data. It is based on the fractal quality of constructive part of microacceleration field. The algorithm can be applied for technological space laboratories only if a constructive part of microacceleration field is prevalent.
The following article deals with the algorithm applied to recover lost microacceleration data. The algorithm allows recovering on the basis of available part of measuring data. It is based on the fractal quality of constructive part of microacceleration field. The algorithm can be applied for technological space laboratories only if a constructive part of microacceleration field is prevalent.
Basic Development Stages of the Algorithms Applied to Recover Lost Microacceleration Data and Check Efficiency of Measuring Equipment on the Board of Space Laboratory
doi:10.11648/j.ajae.s.2016030101.13
American Journal of Aerospace Engineering
2015-07-28
© Science Publishing Group
K. I. Potienko
Basic Development Stages of the Algorithms Applied to Recover Lost Microacceleration Data and Check Efficiency of Measuring Equipment on the Board of Space Laboratory
3
1
16
16
2015-07-28
2015-07-28
10.11648/j.ajae.s.2016030101.13
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.13
© Science Publishing Group
Natural Convection in an Anisotropic Non-Darcy in Differentially Heated Porous Cavity Under G-Jitter
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.14
Natural convection in a square porous cavity under sinusoidal g-jitter has been studied for hydro dynamically and thermally anisotropic porous media. The difference with the homogeneous porous media under sinusoidal g-jitter with the anisotropic porous medium under sinusoidal g-jitter is the circulation pattern change. Fluid flow aligns with the porosity distribution. An effort has also been made to understand the non-Darcy effect for the above mentioned problem. It has been observed that at very low velocities, results from the porous media following Darcy’s model and Forchheimer’s equation (non- Darcy model) closely resemble each other. Velocity and pressure behave in a sinusoidal fashion with the same frequency as with the gravitational acceleration. Last but not the least an effort has also been made to understand the behaviors of average Nusselt number in the above mentioned situations.
Natural convection in a square porous cavity under sinusoidal g-jitter has been studied for hydro dynamically and thermally anisotropic porous media. The difference with the homogeneous porous media under sinusoidal g-jitter with the anisotropic porous medium under sinusoidal g-jitter is the circulation pattern change. Fluid flow aligns with the porosity distribution. An effort has also been made to understand the non-Darcy effect for the above mentioned problem. It has been observed that at very low velocities, results from the porous media following Darcy’s model and Forchheimer’s equation (non- Darcy model) closely resemble each other. Velocity and pressure behave in a sinusoidal fashion with the same frequency as with the gravitational acceleration. Last but not the least an effort has also been made to understand the behaviors of average Nusselt number in the above mentioned situations.
Natural Convection in an Anisotropic Non-Darcy in Differentially Heated Porous Cavity Under G-Jitter
doi:10.11648/j.ajae.s.2016030101.14
American Journal of Aerospace Engineering
2015-08-27
© Science Publishing Group
P. Ghosh
S. Tuteja
Natural Convection in an Anisotropic Non-Darcy in Differentially Heated Porous Cavity Under G-Jitter
3
1
21
21
2015-08-27
2015-08-27
10.11648/j.ajae.s.2016030101.14
http://www.sciencepublishinggroup.com/journal/paperinfo.aspx?journalid=309&doi=10.11648/j.ajae.s.2016030101.14
© Science Publishing Group