Application of Genetic Algorithm in Design and Optimization of Proportional-Derivative Fuzzy Controller to Regulate Turbojet Engine Fuel Flow
Morteza
Montazeri
عضو هیات علمی / دانشکده مهندسی مکانیک، دانشگاه علم و صنعت
author
Ehsan
Mohammadi
دانشجوی دکتری / دانشکده مهندسی مکانیک، دانشگاه علم و صنعت
author
text
article
2014
per
This paper presents the design and optimization of proportional-derivative fuzzy controller intended for regulating the fuel flow of a turbojet engine using genetic algorithm. First, with the aim of Wiener modeling approach, a block structure model is proposed for simulating turbojet engine operation. This representation is an appropriate method for control system design. Subsequently, based on the nonlinear nature of the turbojet engines, an initial fuzzy controller is desined which its rules and parameters are tuned in accordance with empirical data and prior knowledge of the engine behavior. Finally, the rules and parameters of the initial controller is optimized with the aim of reducing fuel consumption and improving engine performance in transient mode. Simulation results reveal that the desined controller is capable of reducing fuel consumption as well as improving the engine time response and enhancing the engine performance characteristics like the steady state error, overshoot and rise time.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
3
12
http://www.astjournal.ir/article_5882_03dc529b7c6feb7680bde6f315403afc.pdf
Multidisciplinary Conceptual Design Optimization of Manned Launch Vehicle Using All At Once Method and Simulated Annealing Algorithm
Jafar
roshanian
عضو هیات علمی / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدینطوسی
author
Hossein
darabi
دانشجوی دکتری / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدینطوسی
author
Hadi
Zare
دانشجوی دکتری / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدینطوسی
author
text
article
2014
per
Multidisciplinary design optimization is one of the new methods of design with ability solving complicated problems with large design space including aerospace problems. The purpose of this article is the conceptual design of a two-stage crew launch vehicle with side boosters. Thus, in first phase, in order to achieve a suitable design point, the statistical design technique is used, and then statistical design process is validated by using two degree of freedom simulation and doing energetic-mass calculations. In second phase, multidisciplinary design optimization approach is applied for initial conceptual design optimization. The preferred structure for multidisciplinary design optimization is all-at-once and simulated annealing is used as the optimizer algorithm. Having performed the optimization process, a mass decrease of about 7 tons from missile gross weight was attained with respect to normal simulation results, and as already known, the decrease in gross mass undeniably leads to a consequent decrease in the cost of producing and launching missiles.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
13
22
http://www.astjournal.ir/article_5883_9586afaa11bee7e57c4ccb0c356d3571.pdf
Analysis of Effect of Freeplay on Flutter of an Airfoil in Incompressible Subsonic Flow
Saeed
Irani
عضو هیات علمی / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
Saeed
Sazesh
کارشناس ارشد / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
text
article
2014
per
In this study the compatibility of nonlinear random vibration analysis is used and extended to the nonlinear aeroelastic systems to investigate the instability of these systems with using neither time domain analysis nor limit cycle oscillations. To this aim a 2-degree of freedom airfoil with freeplay nonlinearity under quasi steady flow is used. At first one random Gaussian white noise is added to the aerodynamic lift force then the statistical linearization and the random vibration analysis of the nonlinear systems are used to obtain a nonlinear map of variance of the response with flow velocity as the control parameter. This nonlinear map leads to a nonlinear algebraic equation which consists of two parameters as the flow velocity and variance of the response. Solving this nonlinear equation for various flow velocities, ultimate to calculate the flutter speed where maximum of variance of the response happens. Finally the jump phenomenon is investigated where tangent bifurcation point occurs.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
23
29
http://www.astjournal.ir/article_5884_646dceda0f0a101ff488bbb09cd17fa1.pdf
Chirality Effects on Mechanical Properties of Single-Walled Carbon Nanotubes
Mahnaz
Zakeri
عضو هیات علمی / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
Mahdi
shayanmehr
کارشناس ارشد / دانشکده مهندسی هوافضا، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
text
article
2014
per
Carbon nanotubes (CNTs) are carbon allotropes with unique characteristics. Structure of each nanotube is defined by a vector called chiral vector. In this paper, entering the nanotube length and two input values of m and n into a simple algorithm, the positions of carbon atoms are determined and the full geometry of nanotubes is depicted. Then, different kinds of nanotubes are simulated and their mechanical properties are determined using finite element method. Comparison of the results with previous results existing in the literature reveals good precision of this algorithm in simulating nanotubes geometry. The results show that CNTs have the most tensile modulus in chiral angles between 17-22 degree, which is about 1TPa.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
30
37
http://www.astjournal.ir/article_5885_5fabebd0ad4c72a5375e6f707d4d5cec.pdf
Experimental Consideration of Strain Rate Effect on Deformation and Failure of Thin-walled Metal Shells Subjected to Dynamic Loading
Jamal
Zamani
عضو هیات علمی / دانشکده مهندسی مکانیک، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
Amin
Zamiri
کارشناس ارشد / دانشکده مهندسی مکانیک، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
Ehsan
Yavari
دانشجوی کارشناسی ارشد / دانشکده مهندسی مکانیک، دانشگاه صنعتی خواجه نصیرالدین طوسی
author
text
article
2014
per
In this paper an experimental study of the behavior of thin-walled structures carrying explosives, has been considered, The most important part of the research is to determine the effect of strain rate on the range 10-4 to 10+5, on the maximum Deformation of structures. For quasi-static and dynamic loading at low rates (10-4 to 1 (S-1)), the hydrostatic system has been used. And high dynamic loading rates (10+4 to 10 +5 (S-1)) the explosion tests are used. Structures used in the experiments, three millimeters thick aluminum AA1050 with three different lengths of 17 to 34 cm. To ensure the accuracy of the test results conducted three experiments were considered. Finally, amount of pressure required for maximum deformation at different loading conditions, determined and compared. Results show an increase in maximum pressure of the dynamic loading compare to the quasi-static loading, with a ratio of 1.57 to 1.81. Certainly, changes in the behavior of structure, represent the sensitivity of the structural material to the Strain rate loading, this means that an increase in strain rate, causes increase in the yield, Which In this study, the increase in yield stress is fully determined.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
38
45
http://www.astjournal.ir/article_5886_2b1398bee8db123411805aca6917da59.pdf
Experimental Investigation of Pressure Dependency of Solid Propellant Sound Speed by Ultrasonic Technique
Ebrahim
Ataee
کارشناس ارشد / گروه پژوهشی شیمی، پژوهشکده سامانههای حمل و نقل فضایی، پژوهشگاه فضایی ایران، سازمان فضایی ایران
author
Hojat
Ghassemi
عضو هیات علمی / دانشکده مهندسی مکانیک، دانشگاه علم و صنعت ایران
author
Ebrahim
Zanjirian
عضو هیات علمی / پژوهشکده سامانههای حمل و نقل فضایی، پژوهشگاه فضایی ایران
author
text
article
2014
per
In order to determine accurate solid propellant burning rate by ultrasonic method, pressure dependency relationship of sample`s sound speed should be applied on thickness algorithm. This article presents comprehensive background in ultrasonic method and its application in burning rate measurement. Also pressure dependency of sound speed for several composite propellants based on HTPB had been investigated. Experimental samples with 30 mm length and 30 mm diameter had been tested under different pressure. The sound speed values were determined in each pressure by measuring the flight time of omitted ultrasonic waves and its returned echoes. The pressure varied from zero to 100 bar and the experiments were done for both pressurization and depressurization conditions. The results show that the samples sound speed depends slightly on pressure. Furthermore this relationship is linear. For instance it has been showed that pressure dependent for the speed of sound of HTPB sample had varied over 40 m/s for 1640 m/s average value. Other cases reviewed in this study were to evaluate the effect of pressure on sound speed for variety composition of HTPB with AL and AP particles. At the end some relevant experiments were done for uncertainty analysis of sound speed measurement. 3% uncertainty which is obtained for the sound speed measurements for HTPB is acceptable in comparison with other scientists` experimental results.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
46
59
http://www.astjournal.ir/article_5887_d458e230ae8a23b9327865b967c78a30.pdf
Design of a Navigation System for an Unmanned Air Vehicle Equipped with a Bearing-Only Sensor
Saeed
Mohammadlou
کارشناس ارشد / دانشگاه آزاد اسلامی، واحد گرمسار، باشگاه پژوهشگران و نخبگان جوان
author
Habib
ghanbarpour
عضو هیات علمی / دانشکده مهندسی هوافضا، دانشگاه صنعتی شریف
author
Ali
Jabbar Rashidi
عضو هیات علمی / مجتمع برق و الکترونیک، دانشگاه صنعتی مالکاشتر
author
text
article
2014
per
In this paper, we have utilized Simultaneous Localization and Mapping (SLAM) problem to design a navigation algorithm for an Unmanned Air Vehicle (UAV). In our scheme, a bearing-only sensor has been installed on UAV as an external sensor that measures the relative bearing angles between the vehicle and unknown landmarks on the ground. SLAM algorithm helps us to reach precise estimates for vehicle states and the position of landmarks at the same time. Extended Kalman Filter has been used as a fusion mechanism to combine the received measurements from external sensor and provided data by Inertial Navigation System (INS). Moreover, for finding a precise location for landmarks when the UAV observes them for first time, we have used a Delayed Constrained Initialization approach. When UAV reaches to the end of the considered trajectory, it flies through the trajectory for second time in which the UAV utilizes the stored data in previous flight to enhance the accuracy of state estimates. Finally, simulation results show the performance of the proposed approach in design of a navigation algorithm for UAVs.
Aerospace Knowledge and Technology Journal
Malek ashtar University of Technology
2322-1070
2
v.
1
no.
2014
60
68
http://www.astjournal.ir/article_5892_70cec11f30945e73e76d14b249e7399a.pdf