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International Review of Aerospace Engineering - June 2011 (Vol. 4 N. 3) - Papers

Designing Flight Simulator Based on Fuzzy Model of Human’s performance in the Pursuit-Evasion Air Combat
Comparison the Operation of Genetic Algorithm and Particle Swarm Optimization in Controlling a Microturbine Generation System
Analysis of Linear Array of Triangular Microstrip Antennas Using High Temperature Superconducting (HTS) Patches
Edge End Clamped Boundary Conditions for Analysis Transient Free Vibration Two Kind of Functionally Graded Material Circular Cylindrical Shell based on 3D Higher-Order Deformation Theory Using Hamilton's Principle
Finite Element Method for Analysis Vibration a Functionally Graded Cylindrical Shell with Effects Simply Support-Simply Support boundary conditions
3D Higher-Order Shear Deformation Plate Theory with Using Hamilton's Principle Based Clamped-Simply Support Boundary Conditions under Analysis Vibration Two FGM Circular Cylindrical Shell
Slotted Aloha protocol with Reed-Solomon Erasure coding
Fatigue Crack Open Effect to Lamb Waves in Thin Al Sheet
Detection of Separation Bubble Using Spectral Analysis of Fluctuating Surface Pressure
Vortex Flow Asymmetry of Slender Delta Wings

International Review of Aerospace Engineering - Papers

Designing Flight Simulator Based on Fuzzy Model of Human’s performance in the Pursuit-Evasion Air Combat
by Reza Ghasemi

Vol. 4. n. 3, pp. 122-129

Abstract - In this paper, we propose a new method for a three dimensional fuzzy model of pilot's performance in the air combat. A sixth order nonlinear point mass vehicle model is considered for an aircraft's flight dynamics to model pilot's performance and generate a complicated offensive maneuver in an air combat, we need to mimic expert's decisions. This has been done by introducing a fuzzy model consisting of three distinct blocks that are fully discussed in the paper. The proposed model is robust against noise. We consider two cases for model, the first is the model of the pilots with constant specific energy and the other is with the varying specific energy. The simulator has been designed based on the proposed fuzzy model.

Keywords: Fuzzy modeling, Pilot's performance, linguistic model, Maneuvering target, pursuit-evasion game- Flight Simulator.

Comparison the Operation of Genetic Algorithm and Particle Swarm Optimization in Controlling a Microturbine Generation System
by Masoud Sabaghi, Seyed Morteza Alizadeh, Seyed Reza Hadian, Goodarz Cheraghi, Ali Bamani

Vol. 4. n. 3, pp. 130-136

Abstract - In this study, we deal with the role of two of the most popular artificial intelligence optimization methods i.e. Genetic Algorithm (GA) and Particle Swarm Optimization ( PSO) in controlling a microturbine generation (MTG) system operation worked in grid connected mode. Firstly we present a dynamic model of the microturbine generation system in grid connected operation. In the second step, we optimize the active power injected to the grid in order to follow the desired active power with the lowest error. We optimize the difference between active power and the desired active power using genetic algorithm and particle swarm optimization. Finally, we compare the results gained by each of these methods. The results show that PSO has better effectiveness. The model is developed in MATLAB/Simylink.

Keywords: Distributed generation, Genetic Algorithm, Inverter, Microturbine, PM generator, Particle Swarm Optimization.

Analysis of Linear Array of Triangular Microstrip Antennas Using High Temperature Superconducting (HTS) Patches
by O. Barkat

Vol. 4. n. 3, pp. 137-142

Abstract - This paper describes a study of linear array of superconducting triangular microstrips implanted in anisotropic substrate. The moment method in the spectral domain is used to study the scattering properties of equilateral triangular antennas. In this method, the electric field integral equation for a current element on a grounded dielectric slab of infinite extent is developed by basis functions. An improved analytical model is presented taking into account anisotropic substrate, and superconducting material for the triangular patch. The far zone radiation fields are derived using Huygens principle and pattern multiplication approach. The obtained results are compared with previously published work, they were in good agreement.
Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved

Keywords: Superconducting triangular, Linear array, Radiation pattern, Full wave, Swarm particle.

Edge End Clamped Boundary Conditions for Analysis Transient Free Vibration Two Kind of Functionally Graded Material Circular Cylindrical Shell based on 3D Higher-Order Deformation Theory Using Hamilton's Principle
by M. R. Isvandzibaei

Vol. 4. n. 3, pp. 143-151

Abstract - The effects of the FGM configuration are studied by studying the frequencies of two FGM cylindrical shells. Type I FGM cylindrical shell has Nickel on its inner surface and stainless steel on its outer surface and Type II FGM cylindrical shell has stainless steel on its inner surface and nickel on its outer surface. The study is carried out based on third order shear deformation shell theory. The objective is to study the natural frequencies, the influence of constituent volume fractions and the effects of configurations of the constituent materials on the frequencies. The properties are graded in the thickness direction according to the volume fraction power-law distribution. The governing equations are obtained using energy functional with the Hamilton's principle. The boundary conditions in this cylindrical shell made of two material is clamped-clamped (C-C). Results are presented on the frequency characteristics, the influence of the constituent various volume fractions on the frequencies for a Type I, II FGM cylindrical shell.

Keywords: Clamped, Free, Cylindrical shell, Hamilton’s principle.

Finite Element Method for Analysis Vibration a Functionally Graded Cylindrical Shell with Effects Simply Support-Simply Support boundary conditions
by M. R. Isvandzibaei

Vol. 4. n. 3, pp. 152-158

Abstract - Study of the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is very important. The objective is to study the natural frequencies and the effects simply support-simply support boundary conditions on the natural frequencies of the functionally graded cylindrical shell. The study is carried out using third order shear deformation shell theory. The properties are graded in the thickness direction according to the volume fraction power-law distribution. The governing equations are obtained using energy functional with the Rayleigh-Ritz method. The governing equations of motion of functionally graded cylindrical shells are derived based on third order shear deformation shell theory. Results are presented on the frequencies characteristics and the effects of simply support-simply support boundary conditions on edge end functionally graded cylindrical shell.

Keywords: Clamped, Rayleigh Ritz, FGM, Cylindrical Shell.

3D Higher-Order Shear Deformation Plate Theory with Using Hamilton's Principle Based Clamped-Simply Support Boundary Conditions under Analysis Vibration Two FGM Circular Cylindrical Shell
by M. R. Isvandzibaei

Vol. 4. n. 3, pp. 159-167

Abstract - The effects of the FGM configuration are studied by studying the frequencies of two FGM cylindrical shells. Type I FGM cylindrical shell has Nickel on its inner surface and stainless steel on its outer surface and Type II FGM cylindrical shell has stainless steel on its inner surface and nickel on its outer surface. The study is carried out based on third order shear deformation shell theory. The objective is to study the natural frequencies, the influence of constituent volume fractions and the effects of configurations of the constituent materials on the frequencies. The properties are graded in the thickness direction according to the volume fraction power-law distribution. The governing equations are obtained using energy functional with the Hamilton's principle. The boundary conditions in this cylindrical shell made of two material is clamped-simply support (C-SS). Results are presented on the frequency characteristics, the influence of the constituent various volume fractions on the frequencies for a Type I, II FGM cylindrical shell.

Keywords: Simply Support, Clamped, FGM, Cylindrical shell, Hamilton’s principle.

Slotted Aloha protocol with Reed-Solomon Erasure coding
by M. Belattar, D. Benatia, M. Benslama

Vol. 4. n. 3, pp. 168-172

Abstract - The aim of this paper is the improvement of slotted Aloha performance, using Reed-Solomon erasure coding scheme, this technique can be used in Satellite communication to recover lost packets. Although erasure coding increases offered load, the probability of successful packet transmission can also be increased. An approach to define the behavior of throughput of erasure scheme based on fitting method is presented. The results obtained give a best approximation with polynomial form of throughput in function of the offered load.

Keywords: Slotted ALOHA, Reed-Solomon code, error probability, Erasure capability.

Fatigue Crack Open Effect to Lamb Waves in Thin Al Sheet
by Vitalijs Pavelko, Helge Pffeifer, Martine Wevers

Vol. 4. n. 3, pp. 173-179

Abstract - The phenomenon of the Lamb wave interaction with fatigue crack in Al2024-T3 sheet was investigated at cyclic loading. Mentioned effect is associated with the crack open/close that change acoustic impedance of a crack. Analytical simulation of fatigue crack opening using the generalized Dugdale’s model of a crack in thin plate shows good accordance between the intensity of ultrasonic signal and a crack opening. The perspective of application for structural health monitoring (SHM) of aircraft.

Keywords: Fatigue Crack, Lamb Wave, Aircraft, Structural Health Monitoring.

Detection of Separation Bubble Using Spectral Analysis of Fluctuating Surface Pressure
by N. A. Ahmed

Vol. 4. n. 3, pp. 180-183

Abstract - Lift stall at the leading edge is often characterized by the formation of separation bubble. Separation bubble is an important topic in fluid mechanics of fundamental significance that is not confined to aerospace applications. However, detection and analysis of the formation of a separation bubble is a difficult task. In this paper, a new methodology is described to detect the existence of separation bubble using a fluctuating pressure measurement technique. The tests were conducted on a circular cylinder in an open circuit, closed circuit wind tunnel at the aerodynamics laboratory of the University of New South Wales over the flow of a circular cylinder at a Reynolds number of 6.8 x 104 under turbulence intensities that varied from 0.2% to 0.7%. The results are very promising and suggest that spectral properties may be used with good effect to indicate the occurrence, location and characterization of separation bubble.

Keywords: Separation bubble, fluctuating surface pressure, spectral analysis.

Vortex Flow Asymmetry of Slender Delta Wings
by G. Behfarshad, N. A. Ahmed

Vol. 4. n. 3, pp. 184-188

Abstract - It is generally believed, that on slender delta wings, there is a critical state at which strong asymmetric vortices are found along the leading edge on the lee-side of delta wing. These asymmetric vortices can lead to high lateral forces even when slender delta wing is at zero angle of yaw. Some experimental studies reported cast considerable doubt as to the validity of the above explanations. A wind tunnel investigation was, therefore, performed to study afresh this phenomenon. The flow over four sharp edged delta wings with aspect ratio ranging from 0.56 to 1.46 were investigated using flow visualization with laser light sheet and some surface pressure and hot wire measurement. The tests were conducted for angles of attack ranging from 0 to 30 deg and at a free-stream velocity of 30m/s corresponding to a Reynolds number of 4.8×10⁵ based on the center line chord of the wing. The results obtained suggest the absence of asymmetry in vortex core position in the flow.

Keywords: Vortex flow, Asymmetry, Delta wing.