bluuebunny/crossref_metadata_2025 huggingface dataset:
Interleaved Boost Converter for Photovoltaic Energy Generation
Authors: Karthikeyan V. , Jamuna Venkatesan , Rajalakshmi D.
Published: August 2014

Renewable energy is derived from natural resources and most commonly used renewable energy system is photovoltaic cells. DC-DC boost converter serves many purposes and usually required in many applications which has a low output voltage such as batteries, photo-voltaic cell. In this paper interleaved boost converter (IBC) topology is discussed for solar energy generation. IBC have better performance characteristics compared to a conventional boost converter due to increased efficiency. DC-DC IBC have been considered and analyzed by input current ripple and output current ripple and output voltage ripple. The waveforms of voltage and current ripples and the output voltage are obtained by using MATLAB/SIMULINK are presented. The design of inductor, capacitor and analysis of ripples has been presented.
Embedded Model Based Onboard Diagnosis of Hybrid Power Generation System
Authors: Beula S. , Arivuselvam B.
Published: August 2014

Renewable energy is the energy which comes from natural resources such as wind, rain, sunlight, and tides. These resources are generally renewable can be naturally replenished. Therefore, for all practical purposes, and resources can be considered as inexhaustible unlike dwindling conventional fossil fuels. This renewable energy has to be used in an efficient way for that Hybrid systems are used. This paper shows the monitoring of a hybrid power unit. The monitoring system has been conceived for comparing the performance of the power generation unit with reference. Depending upon the performance the fault can be analyzed. The fault can be viewed in local and remote location. LABVIEW software is used for data acquisition and analyzing a fault.
Harmonic Reduction in 3 Phase Diode Clamped Multilevel Inverter by Capacitor Voltage Balancing Using SVM and Fuzzy Controller
Authors: Jinesh C. , Ellis Chandla , Nisha A. Alhamdhu
Published: August 2014

Multilevel converters are effective means of reducing harmonic distortion and dv/dt of the output voltages, which makes this technology applicable to utility interface and drives. In this paper, Multilevel Converter for power conversion is proposed. The voltage balancing at the terminal is achieved through proper selection of switching states. The switching scheme is defined by Space Vector Modulation. A fuzzy controller need to be interfaced with the system using SVM for optimal voltage operation and error minimization .The main feature of the proposed SVM switching strategy is that it enables balancing voltages of the dc capacitors, with no requirement of additional controls or auxiliary devices and higher magnitude of ac-side voltage with reduced harmonic concept in the output waveform. The proposed idea is demonstrated in simulation to evaluate the validity of the concept in MATLAB.
Performance Analysis and Control of Double Fed Induction Generator Using Modified Direct Power Control Scheme during Nonlinear Loading
Authors: Raj I. Andrew Xavier , Prasanna S.C. , Sivakumar P.
Published: August 2014

Renewable energy resources has given rise to the systems that transmit and distribute electricity. Recent developments in the wind energy as distribution generation systems in the distribution networks is gaining popularity as a new sources of energy. The integration of renewable energy in to the power system causes severe challenges for the control and protection of the distributed system. A careful operation and design of distribution systems with renewable energy resources should be carried out. This paper describes the dynamic modeling and simulation results of DFIG wind turbine during nonlinear loading. During nonlinear loading the overall performance gets considerably degraded due to the effect of negative sequence component and also the power produced by the DFIG gets considerably derated. To eliminate this effect a suitable control technique should be applied. Direct Power Control (DPC) scheme is implemented along with Proportional Integral (PI) controller. The DPC directly controls the Stator active and reactive powers, while the PI controllers is used to regulate the positive and negative sequence component. The proposed DPC-PI control strategy is verified by the simulation results during nonlinear loading. The models have been developed by means of MATLAB/SIMULINK software.
Multi-Objective Economic Emission Load Dispatch Solution Using Evolutionary Algorithm with and without Considering Wind Power Penetration and Valve Point Effect
Authors: Thenmalar K. , Ramesh S. , Anuja K.S.
Published: August 2014

The electrical power system is considered as the most complex man-made systems mainly due to their wide geographical coverage. Electrical energy industries contributes environmental pollution which rise questions concern environmental protection and methods of eliminating or reducing pollution from power plants either by design or by operational strategies. Electric power plants are mainly aimed to operate al low fuel cost strategies .In this paper a Multi –Objective Economic Emission Load Dispatch problem is solved to minimize the emission of nitrogen oxides (NOx) , oxides of other fuels that release during generation of electricity and fuel cost considering both Thermal generators and Wind turbines. A large number of iterations and oscillation are those of the major concern in solving the economic load dispatch problem by using the BFO(bacterial foraging optimization) method. By applying BFO method the economic dispatch problem is optimized to minimize the total generation cost of a power system while satisfying various equality and inequality constraints. The effect of Wind power on overall emission is also investigated here using Quadratic programming by wolf’s method. This method has better convergence characteristic. Wolf’s method is an extended simplex procedure which can be applied to Quadratic programming problems in which all the problem variables are non-negative.
Voltage Compensation with Interline Power Flow Controller (IPFC) Using Control Magnitude and Phase Angle Control
Authors: Monikandan A.S. , Nair N. Kesavan
Published: August 2014

The Interline Power Flow Controller (IPFC) is a voltage-source-converter (VSC)-based flexible ac transmission system (FACTS) controller for series compensation in a multiline transmission system of a substation. The capability of injecting series voltages with controllable magnitude and phase angle makes it a powerful tool for better utilization of existing transmission lines in a multiline transmission system. IPFC is used to regulate active and reactive power flow in a multiline system, usually. In this paper, a control method for IPFC is proposed to control magnitude and phase angle of one sending bus of a substation. All degrees of freedom of IPFC and decoupled synchronous frame concept are used in the proposed control structure. Simulation results in Matlab/Simulink are presented to show the capability of IPFC in compensating the bus voltage.
Distance Based Clustering Algorithm for Energy Efficiency in Wireless Sensor Networks
Authors: Kalaiselvi K. , Suresh G.R.
Published: August 2014

In wireless sensor networks Energy-efficient routing is an important issue due to the limited battery power within the network, Energy consumption is one of the important performance factors. Specifically for the election of cluster head selection and distance between the cluster head node and base station. The main objective of this proposed system is to reduce the energy consumption and prolong the network lifetime. This paper introduces a new clustering algorithm for energy efficient routing based on a cluster head selection
Review on MRI Brain Tumor Segmentation
Authors: Blessy S.A. Praylin Selva , Sulochana C. Helen
Published: August 2014

Accurate segmentation of brain tumor from MRI is crucial in computer aided diagnosis as well as in other medical imaging applications. Brain tumor segmentation is a challenging task due to the diverse appearance of tumor tissues. A variety of brain tumor segmentation techniques have been explored in the literature. Here, a brief review of different brain tumor segmentation techniques has been discussed with their merits and demerits. We conclude with a discussion on the trend of future research in brain tumor segmentation.
Optimal Feature Selection for Carotid Artery Image Segmentation Using Evolutionary Computation
Authors: Farook I. Mohammed , Dhanalakshmi S. , Manikandan V. , Venkatesh C.
Published: August 2014

Atherosclerosis is hardening of arteries due to high blood pressure and high cholesterol. It causes heart attacks, stroke and peripheral vascular disease and is the major cause of death. In this paper we have attempted a method to identify the presence of plaque in carotid artery from ultrasound images. The ultrasound image is segmented using improved spatial Fuzzy c means algorithm to identify the presence of plaque in carotid artery. Spatial wavelet, Hilbert Huang Transform (HHT), Moment of Gray Level Histogram (MGLH) and Gray Level Co-occurrence Matrix (GLCM) features are extracted from ultrasound images and the feature set is reduced using genetic search process. The intima media thickness is measured using the proposed method. The IMT values are measured from the segmented image and trained using MLBPNN neural network. The neural network classifies the images into normal and abnormal.
Constitutive Models for Uniaxially-Post-Buckled Square Lattices
Authors: Parra Edgar A. Flores , Spadoni Alessandro
Published: August 2014

The objective of this paper is to analyse the mechanical stress-strain response of an ini-tially uniaxially-post-buckled periodic structure. This requires selecting a representative volume ele-ment (RVE) that contains all the micro-structural features and responds as the infinite medium when subjected to uniform load and boundary conditions. Selection is done by analysing the stress-strain response for macro-cells of increasing size as well as identifying dominant length scales with a 2D-FFT. For a uniaxially–post buckled square lattice, the RVE is found to be a Y3x3 (3x3 unit cells for the undeformed configuration). A study for the post-buckled behaviour of the pre-stressed RVE, with in-ternal components modelled as long slender beams, beyond elastic buckling is presented. Incremental constitutive models are then formulated analytically and numerically for loads above the critical load.
Quasi-Static Compressive Properties of Aluminium Foams with Functionally Graded Properties
Authors: Peixinho Nuno , Pinto Paulo , Silva Filipe , Soares Delfim
Published: August 2014

This paper presents experimental results of compressive behavior of aluminium alloy metal foams with controlled pore morphology. Different types of metal foams were analyzed, having uniform cell structure with different pore size and gradient variation of cellular structure along length. The test samples were manufactured by lost-wax casting using 3D printed components for internal structure definition. Results for stiffness and energy absorption were obtained and compared on weight efficiency basis. The results are analyzed regarding the efficiency of the different cell structures and its suitability for energy absorbing application in components subjected to impact or compression loading.
Prediction of Long-Term Compression Strength for Quasi-Isotropic CFRP Laminates
Authors: Kang Jun , Guan Zhi Dong , Liu Zhun , Li Xing , Mu Jun Wu , Gao Tian Yu
Published: August 2014

Long-term strength prediction method is developed based on three theories: accelerated testing methodology (ATM), strain invariant failure theory (SIFT) and progressive damage analysis (PDA). It can predict the strength and damage at a given failure time. Net resin 5228A was experimented by dynamic mechanical analysis and static tensile loading under various temperatures to determine the time-temperature shift factors and master curve of Young’s modulus. Unidirectional laminates of CCF300/5228A were tested under different temperatures to calculate the SIFT/ATM critical parameters. Long-term strength of quasi-isotropic composite laminates (QIL) was predicted. Good agreement between numerical results and experiments is observed, which demonstrates the applicability of this method.
A Study on the Tensile Strength and Thermal Property of CFRP Using Infrared Thermography Camera
Authors: Shin Hee Jae , Cha In Pyo , Lee Min Sang , Kim Tae Ho , Yun Hyun Kyung , Kwac Lee Ku , Kim Hong Gun
Published: August 2014

The fiber is considered the most important element in fiber reinforced composite materials, as it generally occupies the largest volume in a composite material; further, delivers the heaviest loads. therefore, it is important to select types, quantity and proper stacking angles of the fiber. In this study, the fiber directions were arranged in different orientation angles, i.e. in symmetric (0°/0°,15°/15°,30°/30°,45°/45°,90°/90°) and asymmetric (0°/15°,0°/30°,0°/45°,0°/90°), to analyze the tensile strengths depending on the fiber orientation angles through the tensile test. In addition, a thermal imaging camera was used to investigate the thermal characteristics of the test specimens generated during the tensile test. the tensile strength showed a tendency of decreasing while the orientation angle increased. the maximum temperature generated when the fracture occurred increased at the fiber orientation angle of 30°, and showed a tendency of decreasing as the orientation angle increased.
Simulation of Sinusoidal Vibration Control Algorithm Based on Hydraulic Vibration Table
Authors: Li Xiao Lin , Yan Xia
Published: August 2014

In this paper, the model of hydraulic vibration system is established and sinusoidal vibration control algorithm is discussed and studied. A sinusoidal control hydraulic vibration system is designed. By simulation, this system has good frequency response characteristic and sine sweep control function.
Dynamics Characterization of Missiles with Control Flaps Based on CFD
Authors: Liu Xu , Liu Wei , Zhao Yun Fei
Published: August 2014

Numerical studies were carried out on the dynamics of the Basic Finner missile under supersonic velocity based on the three-dimensional unsteady N-S equation. Second-order upwind NND scheme finite volume was used to discretize the spatial derivative term of the flow-controlled equation group. The LU-SGS containing dual time steps was used to obtain higher efficiency and precision of time solution. A numerical model representing the relationship between the unsteady aerodynamic force/moment coefficients and state variables under single DOF (degree of freedom) pitching and rolling movements was built from the Etkin unsteady aerodynamic model. The numerical algorithm for solving damping-in-pitch derivatives and damping-in-roll derivatives by forced-harmonic analysis was proposed. The M910 target practice, discarding sabot with tracer (TPDS-T) was used as a validation example and proved that the numerical calculation gives the same result as the experiment. By simulating the forced pitching and rolling vibration of Basic Finner, the numerical identification succeeded in obtaining the damping-in-pitch derivative and damping-in-roll derivative to a higher precision than the calculated result obtained by the quasi-steady Euler equation. Besides, to address the longitudinal and horizontal cross coupling induced by the pitching movement, numerical identification was also carried out on the cross coupling derivative of Basic Finner when under forced pitching vibration.
Rigid-Flexible Coupling Dynamics Analysis for a Twin-Rotor Piston Engine
Authors: Zou Teng An , Pan Cun Yun , Zhang Xiang , Zhang Lei
Published: August 2014

Twin-rotor piston engine (TRPE) is a new differential rotary engine, which is still under developing. In this paper, a rigid-flexible coupling dynamics model was established for the prototype TRPE-350. By combining the multi-body dynamics simulating software RecurDyn and the finite analysis software ANSYS, the TRPE′s performances were studied. Vibration analysis for rigid-flexible coupling model was analyzed. The simulation results can be found that the simulated overall changing trends match with the actual movement of the TRPE very well. So it provides a theoretical tool for further optimization and improvement of this engine.
The Approach to the Noise and Vibration Management in the Power Products Design
Authors: Kmita Grzegorz , Kozupa Michal , Platek Robert , Krol Julita , Juszkiewicz Grzegorz
Published: August 2014

Design considerations related to noise pollution have become extremely important recently in many industries. Despite the wide range of applications and various noise spectrum the methodology remains quite common. The power products operating in the power systems are very often affected by a noise emission side effect and must be carefully designed with respect to the resulting noise emission and its influence on the surrounding environment consequently. Noise management, design concept examples as well as the modern techniques for noise sources characterization in transformers are presented in this paper.
The Specification of Unknown Force within Dynamic Analysis of Slider Crank Mechanism by Three Various Access
Authors: Monkova Katarina , Cizikova Andrea , Monka Peter
Published: August 2014

The article deals with the specification of unknown force within dynamic analysis of slider crank mechanism by three various access. The method of virtual work was used at the analytical solution; the principle of superposition was used at the graphical solution and the software PTC Creo was used at the solution with computer aid. All three types of the solution have their self-advantages and disadvantages. The final decision, which of methods should be selected for the solution, depends on required result precision and on the abilities of investigator. In all cases, however, it is necessary to know the basic principles of mechanics.
Near-Field Beamforming Source Localization for Gear Transmission in a Semi-Anechoic Room
Authors: Derouiche Abbassia , Hamzaoui Nacer
Published: August 2014

In this study, we discussed the sound sources localization and characterization for a spur gear transmission, which deals with a vibro-acoustic surveillance for predictive maintenance. The technique uses is based on the near-field Beam forming using Bartlett and Capon estimators. The measurements done on the gear transmission with a rectangular phased array of microphones were performed in acoustics and vibration laboratory (LVA) of the INSA of Lyon, in a semi-anechoic room. The gear transmission was considered sometimes open and sometimes closed. The results are presented as an image showing the acoustic field distribution radiated by the gear transmission at the most energetic frequencies. Both estimators have satisfactory results, but even better for the method with high resolution capon.
Ultrasonic Sonic Imaging for a Two Phase System Based on Support Vector Machine Classifier
Authors: Desa Mohd Faizal Mat , Mansor Muhammad Naufal , Junoh Ahmad Kadri , Ahmed Amran , Daud Wan Suhana Wan , Idris Azrini
Published: August 2014

Multiphase flow characterization is an important task for monitoring, measuring or controlling industrial processes. This can be done by means of process tomography. The use of tomographic techniques has been used within the oil industry. One of the potential applications is flow visualization and measurement in producing wells. Research on industrial process tomography consists in obtaining estimated images of a cross section of a pipe or vessel containing or carrying the substances of the process. One category of process tomography is ultrasonic tomography technique. A simple tomography can be built by mounting a number of sensors around the circumference of a horizontal pipe. This includes acquiring and processing ultrasonic signals from the transducers to obtain the information of the spatial distributions of liquid and gas in an experimental column. Analysis on the transducers’ signals will be carrying out to distinguish between the observation time and the Lamb waves. The information obtained from the observation time is useful for further development of the image reconstruction. To obtain the time easily, the time will be calculated from the starting pulse of transmitter signal until the starting peak of receiver signal. Finally Support Vector Machine (SVM) was employed to distinguish of each phase between water and gas.
Experimental Validation of the Modified Continuously Variable Command Law of a Semi-Active Suspension Integrating a Magneto-Rheological (MR) Damper
Authors: Boukerroum Said , Hamzaoui Nacer
Published: August 2014

The present work consists of an experimental performances analysis of a suspension system with two degrees of freedom governed by a semi-active modified continuously variable command (MCVC) law. The internal dynamics of Magneto-Rheological (MR) damper used in this study is highlighted by the modified Bouc-Wen model in the mathematical modelling of the secondary suspension system. After the dynamic characterization of the MR damper, a comparison of performance obtained by this control scheme is carried out from the responses calculated using a numerical model and measured experimentally from a test bench of a semi-active suspension incorporating an MR damper and controlled by a dSPACE control chain.
For a better representativeness of the modified Bouc-Wen numerical model, a rapprochement between the calculated and measured responses for the same dynamic characteristics of the test bench is possible by adjusting the most influential parameters of the numerical model. Through better management of the suspension during the low speeds, the modified Bouc-Wen model is more representative of the real behaviour of the MR damper, given its sensitivity at these low speeds during transitions between compression and expansion phases of the damper.
Preliminary Model Analysis of Acoustic Noise Levels for Space Station
Authors: Feng Yao Qi , Yang Jiang , Feng Guo Song , Wu Yao
Published: August 2014

This paper presents the modeling and analysis method of acoustic noise levels of whole audible frequency range for Chinese Space Station (CSS) module. Using Boundary Element Modeling (BEM), the acoustic analysis model of low frequency range for CSS module was established. The analysis model of high frequency range was created by using Statistical Energy Analysis (SEA) method. Based on the established models, the acoustic noise levels in all areas of CSS module were analyzed and the results for some typical areas are provided. Finally, the acoustic contribution of noise sources according to their spectral characteristics is analyzed and the implementation of noise control methods to reduce acoustic levels in CSS module is discussed.
Research of Human Modeling and Motion Simulation Based on ADAMS
Authors: Ma Chao , Liu Yu Qing , Zhu Xiu Qing
Published: August 2014

The human model in this paper is simplified as a rigid body of 15 segments and the Roberson-Wittenberg method is used to establish the equation of conservation of angular momentum to obtain the control methods of human self-rotation without external force in a weightless environment. And simulation of human dynamic is completed in ADMAS (Automatic Dynamic Analysis of mechanical Systems). The simulation results show that human can generate corresponding body rotation through own limbs rotation in the weightless, and body rotation velocity and angle increase with the moment of inertia and rotational velocity of active body that adds greater torque to joint. Through the analysis of the impact of the angular velocity and torque on the body rotation, a set of self-rotation control strategy for astronaut is proposed in weightless environment.
Comparative Evaluation of Activated Carbons Prepared by Thermo-Chemical Activation of Lignocellulosic Residues Aiming at Phenol Removal
Authors: Alves Cibele C.O. , Franca Adriana S. , Oliveira Leandro S.
Published: August 2014

This paper presents a comparative evaluation of three lignocellulosic residues (coffee husks, spent coffee grounds and pequi husks) as precursor materials in the production of activated carbons (ACs). Results indicate that the precursor material has a significant effect in both physical and chemical aspects of the adsorbent, with the AC based on spent coffee grounds being the most effective for phenol removal, with maximum adsorption capacity comparable to commercial ACs.
Experimental and Numerical Analysis Applied on Steel Bars Cooling
Authors: Silva Paul Campos Santana , Seixas Paulo Henrique Terenzi , Rodrigues Caroline , Fonseca Leonardo , Huebner Rudolf
Published: August 2014

AISI 1020 steel bars cooling have been investigated aiming to obtain their cooling rate during heat treatment. Hot steel bars just taken out of the furnace are piled over other ones that were taken out of the furnace earlier. A mathematical model has been created and implemented using the software EES, Engineering Equation Solver. An experiment was conducted to validate the mathematical model. The experiment consists in three loads of three bars each with a time interval of 5 minutes between them. The initial temperature of each bar was 150oC. The mathematical model can obtain the thermal profile of each bar and the average and maximum deviation when confronted with experimental data were about 8% and 20% respectively.
Low Speed Aerodynamics of Drogue System Refueling of Unmanned Aerial Vehicles
Authors: McAndrew Ian R. , Navarro Elena , Godsey Orin
Published: August 2014

Refueling aircraft has become a significant aspect of military strategy for air forces to work at further distances from safe shores. This paper will address the aerodynamics of the drogue refueling system and in particular its characteristics at low speeds, including head and tail winds. Data from wind tunnel experiments are used to show how the docking when refueling is affected by the lower speeds, position behind the supply aircraft and weather conditions. Possibilities of design improvements and implications are related to the task of refueling Unmanned Aerial Vehicles in-flight
High Swept-Back Delta Wing Flow
Authors: Hoang Thi Kim Dung , Nguyen Phu Khanh , Nakamura Yoshiaki
Published: August 2014

In this study, an experimentally and numerically investigation was carried out to obtain characteristics (lift force, drag force ...) on 74.5 degree Delta wing. The experiment tests were conducted at Hanoi University of Science and Technology low-speed wind tunnel facility, whereas the numerical tests were performed using the commercial computational fluid dynamics software ANSYS/FLUENT. The apparition of the vortices upon the Delta wing caused the negative pressure distribution on the wing which reached a maximum absolute value at the vortex core. The characteristics of high swept-back Delta wing were investigated at air velocity of 10 m/s and attack angle of 20 degree in changing the rolling angle of the wing from 0 to 20 degree.
Determining a Robust, Pareto Optimal Geometry for a Welded Joint
Authors: Barrans Simon , Radhi H.E.
Published: August 2014

Multi-criteria optimization problems are known to give rise to a set of Pareto optimal solutions where one solution cannot be regarded as being superior to another. It is often stated that the selection of a particular solution from this set should be based on additional criteria. In this paper a methodology has been proposed that allows a robust design to be selected from the Pareto optimal set. This methodology has been used to determine a robust geometry for a welded joint. It has been shown that the robust geometry is dependent on the variability of the geometric parameters.
Airborne Sensor Model Position Fidelity Determination for Combat Aircraft Simulators
Authors: Kumar P.Suresh , Kumar K. Senthil
Published: August 2014

Airborne sensors become a primary system in any combat program and the effectiveness depends on the coverage spectrum of the sensors and also the ability of flying machine. However evaluating the mission functionalities using sensors in flight involves tasks namely, Man Machine interface evaluation, Sensor function capability evaluation, System interface evaluation, Performance evaluation, pilot work load etc needs to carried out and the issues observed during the flight test needs to be cleared before accepting the system. It is one of the challenging task for any combat aircraft development program and proving require time, effort and also may lead to time and cost overrun. To minimize the effort one of the method adopted in recent flight development programs are using high fidelity sensor model to evaluate the mission function in the simulator which will reduce the actual test required in flight.
Flight simulators during development of combat aircraft program have increased drastically in recent times with new technologies, possible to bring realism in a close room environment. However the success of any simulators depends on the fidelity of each subsystem integrated with in the simulator. Simulator contains simulation model which represents system in the aircraft world and the system which represents the outside world in a simulated manner. Mathematical based Avionics and weapon system Sensor simulation models is one of the major sub systems in any combat simulator and its level of usage depends on its fidelity. This paper proposes a unique and new methodology for evaluating the fidelity of simulated sensors used in the combat simulators. System identification technique allows generating mathematical model for dynamic systems having multiple input and output parameters. The developed model using System Identification Technique is a referent model through which the sensor model fidelity is evaluated.
Design and Development of Vertical Takeoff and Horizontal Transition Mini Unmanned Aerial Vehicle
Authors: Krishnakumar R. , Kumar K. Senthil , Anand T.
Published: August 2014

In recent years Unmanned Aerial Vehicles (UAV) has become a significant segment of the aviation industry. They can be chosen to be designed as fixed wing or Rotary wing type. Fixed-wing aircraft has the performance of fast forward movement, long range and superior endurance due to its gliding capabilities with no power. Unlike the fixed wing models, rotary wing mini-copters are able to fly in all directions, hover in a fixed position with minimal space for takeoff and landing. This makes them the perfect instrument for detailed inspection work or surveying. Implementing a hybrid UAV has the advantages of both fixed-wing and rotary wing UAV. This paper aims to brief on the design, development and testing of a hybrid tilt body UAV with four rotors. The hybrid vehicle comprises two units, an aerial unit and a ground unit. The aerial unit consists of an unmanned aircraft system. The ground unit consists of means to view and post-data processing of video/image sent by the UAV if it is used for aerial surveillance and control, navigate and guide the aircraft. To proceed, a novel hybrid UAV with capability of Vertical Take Off and Landing (VTOL) and horizontal flight is developed and its response during the transition from VTOL to horizontal flight is analyzed.
Application of Peridynamic Theory to Nanocomposite Materials
Authors: Duzzi Matteo , Zaccariotto Mirco , Galvanetto Ugo
Published: August 2014

The purpose of this paper is to describe the computational procedure developed to apply the Bond-based Peridynamic Theory to nanocomposite materials. The goal is to predict the Young’s modulus as a function of the filling fraction of different nanocomposite materials with an accuracy better than that of other methods (like Halpin-Tsai, Mori-Tanaka, FEA models). A displacement control method is adopted here in order to simulate the incremental application of an external load. The constitutive law considered is linear and thus the problem can be seen as a static-linear problem. A description of the model and of the “multiscale approach” is given, supported by a comparison between experimental data and simulation results for different nanocomposites.
Study on Serial MPPT Electrical Power System Stability for Space Application
Authors: Lin Wenl Li , Liu Zhi Gang
Published: August 2014

Instability phenomena such as bus voltage fluctuations are occurred in serial MPPT(Maximum Power Point Tracking) electrical power system. To study the system stability, the system equivalent circuit models were built based on a serial MPPT unregulated bus electrical power system topology for space application. The small-signal equivalent analysis method and solving eigenvalues of state space equations method were adopted to perform stability analysis in two-domain control modes separately, from which the key conclusions were obtained.
Effect of Radiation Induced Charge Neutralization on ELDRS
Authors: Pershenkov V.S. , Bakerenkov A.S. , Yastrebov A.T. , Solomatin A.V. , Belyakov V.V. , Shurenkov V.V.
Published: August 2014

The physical model, procedure of fitting parameter extraction and experimental study of the contribution of radiation induced charge neutralization (RICN) effect on enhanced low dose rate sensitivity (ELDRS) of bipolar devices are presented.
Application of Shainin Design of Experiment Method on Metal Turning Operation
Authors: Saikaew Charnnarong , Chanapal Chollatit , Phrachai Theerawet
Published: August 2014

Surface roughness on machined part is a key performance index of surface quality for metal machining industry. Machining condition is a way to reduce surface roughness of the machined part. This study aimed to determine the significant factors affecting surface roughness and to obtain the optimal machining operation in turning process. The Shainin design of experiment method was used to investigate the effect of five machining factors on surface roughness in turning process of carbon steel. Furthermore, analysis of variance and multiple comparisons were used to determine the optimal machining condition of the significant factors. The results showed that set of the cutting tool angle was the only significant factor affecting the average surface roughness with the optimal operating condition of 120 degree used for reducing surface roughness of the machined part.
Numerical Experiment of a Symmetrical Airfoil with Attack Angle of 5 Degrees in Fluctuating Relative Flow Velocity
Authors: Yokoi Yoshifumi , Fukuta Hiromi
Published: August 2014

In this study, a numerical experiment was performed as what obtains relative velocity fluctuation by oscillating an object with comparatively large amplitude in the direction of flow. Follow pattern and instantaneous fluid force around an In-line forced oscillating symmetrical airfoil (NACA0012) with attack angle of 5 degrees caused not separation in stationary situation were investigated using a vortex method at the Reynolds number Re=4.05×105, in ranges of the oscillation amplitude ratio 2a/c=0.5,1.0,1.5 and 2.0 and the oscillation frequency ratio f/fK=0.25,0.5,1.0 and 2.0 (here, a :half-amplitude of oscillation, c :chord-length, f :oscillation frequency, fK :natural Karman vortex shedding frequency from a stationary airfoil with the attack angle of 90 degrees). As a result of calculations, Separation was observed by oscillating condition even if it was the airfoil of attack angle not separating. It is found that the separation was dependent on the velocity ratio. The characteristics of fluid force are changed by oscillation.
Research on Numerical Simulation of Support Interference for Dynamic Derivatives at Hypersonic Flight Speeds
Authors: Liu Xu , Liu Wei , Zhao Yun Fei
Published: August 2014

The research on dynamic derivative under the dynamic unsteady condition is one of the most difficult aspects of the aircraft development process. For the special experiment of dynamic derivatives, no numerical simulation of support interference has yet been systematically studied. The numerical simulation of support interference for identification of dynamic derivatives with 7o blunted cone under the hypersonic condition was done in this paper. The 2-order Roe scheme and the dual-time-step method based on LU-SGS were respectively applied to discrete of the spatial and time derivative of the unsteady flow. A least square method based on the Etkin unsteady aerodynamic model was used for identification of dynamic derivatives. Hypersonic missile module was adopted as a verification example, and the numerical calculation results are consistent with the experimental results. For two different sting support forms with 7o blunted cone, the impact of sting support interference on dynamic derivatives was studied. Results show the moment coefficients of two support forms under static conditions are essentially the same, while there is a big difference in the pitch damping derivatives under dynamic conditions. The support interference of nonlinear aerodynamic loads resulted from the shock wave induced separation and other unsteady flow structures under dynamic conditions is far more complicated than that under static conditions, and the correction law of support interference under static conditions cannot be applied directly to the unsteady dynamic situations.
Best Attack Position Model for BVR Multi-Target Air Combat
Authors: Yang Rong , Huang Fang Ming , Gong Hua Jun
Published: August 2014

Refer to the characteristics of BVR air combat and multi-target attack for the Fourth Generation Fighters, this paper constructs and computes the model of probability distributions in multi-target kill zone, the model of the best attack path/attack position of multi-target attack. The model of probability distributions in multi-target kill zone considers heading angle and approaching angle of target, distance between fighter and target, maximum off-boresight launching angle and killing angle. The model of the best attack path/attack position considers damage probability to targets by missiles, threat degree to fighter of targets, and threat degree to fighter of residual targets. The paper calculates the simulation data according to the models, analyzes probability distributions in multi-target kill zone of missiles, the best attack path/attack position. The models and simulated results show that the method, which uses kill zone probability model, can improve the damage probability and reduce threat degree from enemy targets.
On the Physical Mechanism of the Interaction of the Microwave Radiation with the Semiconductor Diodes
Authors: Shurenkov V.V.
Published: August 2014

The electronic systems of aerospace techniques include power microwave devices and analog and digital semiconductor devices. The radiation of power microwave devices may effect on the semiconductor devices. So it’s necessary to know the electromagnetic effects of this radiation on the semiconductor devices. The electromagetic effects of the microwave radiation exposure on the semiconductor diodes, the main part of any semiconductor devices, are considered. The changes of current – voltage characteristics of the diodes are explained, outgoing from the model of the recombination of carriers through deep energy level recombination center in forbidden gap induced by microwave radiation field.
Computational Studies of Turbulent Flows in Rotating Radial and 200 Backward Swept Diverging Channels
Authors: Nitheesh George , Govardhan M.
Published: August 2014

Computational study is carried out in radial and 200 backward swept diverging channels rotating about the axial direction. Centrifugal and Coriolis forces, which are developed due to the rotation, affect the secondary flows and flow pattern inside the channel. Reynolds number of Re=36000 with Rotation numbers ranging from 0.0 and 1.5 are chosen for investigation. The variation of velocity and turbulence kinetic energy is studied at several locations of the curved channels. Positive Richardson numbers on the suction side indicates stabilizations of the flow. The stabilization effect increases with increasing Rotation numbers at both the channels.
Analysis of Variable Viscosity Channel Flow under Constant Magnetic Field via Generalized Differential Quadrature Method
Authors: Başkaya Elgiz , Kömürgöz Güven , Özkol Ibrahim
Published: August 2014

In this work, the application of Generalized Differential Quadrature Method (GDQM) to solve a variable viscosity channel flow under constant magnetic field is investigated. The governing equations for channel flow in between two infinite horizontal parallel porous plates subject to convective surface boundary conditions are given in dimensional and non-dimensional forms, pointing out the dimensionless parameters used. These equations are discretized using the GDQM, and solved via Newton Raphson Method. Effects of magnetic field on incompressible electrically conducting fluid velocity and temperature profiles are presented in plots.
Analysis of the Torsional Load Capacity of V-Section Band Clamps
Authors: Barrans Simon , Waterworth Adelle , Sahboun Salahaddin
Published: August 2014

This paper investigates the torsional load capacity of three sizes of V-section band clamps when assembled onto rigid flanges by comparing experimental data with a developed theoretical model. This mode of failure is of particular interest for turbocharger applications where, in use, they are subjected to torsional loading via thermal and vibrational effects. The theoretical model developed allows the impact on torsional load capacity of a number of joint parameters to be investigated and good correlation of the results, incorporating variations in coefficients of friction and dimensions, has been shown for the two larger band sizes. For smaller diameter bands, the experimental data suggests that as the band is tightened, contact with the flange is localised rather than being over the full circumference of the band. The coefficients of friction, in particular that between the flanges, and the position of the contact point between band and flange have been shown to have a significant impact on the theoretical torsional load capacity of V-section band clamps.
Numerical Analysis of the Flow Field in the Nozzle of Hot Water Rocket Motor
Authors: Sun Wei Wei , Wei Zhi Jun
Published: August 2014

Flashing is an important factor in the working process of hot water rocket motor. In order to deeply understand the performance characteristic of hot water rocket motor, a numerical simulation model of the flow field in the nozzle was established in this paper. According to the study of flow field in the nozzle of the motor,it is found that the phase change occurs at the position of the throat,and the flow reaches to supersonic after the throat because of the changing sound speed.The flow in the nozzle can be divided into three processes in this paper: single-phase flow process, flash process and expand-accelerating process.
Characterization and Modeling of Ladle Teeming Process
Authors: Ribeiro Bruno A.B. , Oliveira Leandro S. , Tavares Roberto Parreiras
Published: August 2014

In the continuous casting process, significant amounts of molten steel are left in the ladle during teeming as an established practice to avoid vortexing funnel formation in the end of the teeming process, preventing the ladle slag to be carried over to the tundish. Thus, it was the objective of this work to experimentally and numerically analyze the funnel formation in ladle teeming process. Experiments were designed and carried out to verify the numerical results.
A Hybrid Control Model to Develop the Trajectory-Tracking Controller for a Quadrotor UAV
Authors: Diem P.G. , Anh P.H. , Nguyen Phu Khanh , Hung N.P. , Hien N.V.
Published: August 2014

A new hybrid model of control implementation is developed to realize trajectory-tracking controllers for quadrotor Unmanned Aerial Vehicles (UAV). This model is based on the Computational Fluid Dynamics (CFD) model and hybrid automata in order to accurately implement control parts of these vehicles, and can be applied to most standard quadrotor UAV platforms. The paper brings out step-by-step the controller development lifecycle for a quadrotor UAV, including the configuration and aerodynamic calculation model for the gathering preliminary inputs of the control application, the control analysis of dynamic model and general architecture, as well as the control design performed by specializing hybrid automata. The detailed design model is then converted into the implementation model by using open-source platforms in order to quickly simulate and realize the trajectory-tracking controller for this quadrotor UAV. Finally, this application was completely deployed and successfully taken on trial flights.
Validation of Numerical Simulation Method for Active Flow Control Technology
Authors: Xu Xiao Ping , Zhou Zhou
Published: August 2014

The numerical simulation method of active flow control technology was studied in this paper. The simplified mathematical model of the active flow control is established with unsteady velocity boundary condition at the specific location of model surface. The reliability of flow control model was verified by standard cases of CFDVAL2004, and the capability of capturing micro-jet flow characteristics for Spalart-Allmaras (SA) and Menter’s Shear Stress Transport (SST) turbulence model were analyzed. The results showed that the accuracy of SA turbulence model is better than the SST model, and flow control model meet the accuracy requirements for numerical simulation method.
Symbolic Trajectory Description Using Frescoes
Authors: Popov Vladimir
Published: August 2014

Investigation of symbolic representations of environments plays an important role for solution of various problems of robot visual navigation. In this paper, we study methods of symbolic trajectory description for mobile robot navigation. For this purpose, we use the fresco approach. We consider the problem of salient frescoes selection. In particular, we consider various modifications of the Levenshtein distance method. Also, we use different circular strings methods.
Gait of a Biped Robot Implemented on a FPGA
Authors: Segura Crhistian C.G. , Cortes Jairo
Published: August 2014

A biped robot based its mobility imitating human movements; this development is focused on the movement of the lower limbs. The mobility of the robot is made by servomotors; because they work in a very similar way as the joints of the human’s lower limbs but with some restrictions. The logic of this system was coded on VHDL language to be implemented in a FPGA. The reason for using this hardware; is because it had fast reaction speed, its implementation is friendly and versatile also is able to handle multiple processes in parallel. This paper describes the servo characteristics and how it was used to through an FPGA make possible move a robot who imitates the human movements in the sagittal plane, also show the mechanical design. Shows that the FPGA is better suited in this case than a micro controller to follow multiple paths at the same time.
Gas Turbine Fault Detection and Isolation Using Adaptive Neurofuzzy Inference System (ANFIS)
Authors: Shahriari Behrooz , Shahrbabaki Amin Nazarian , Shahriari Ali
Published: August 2014

This paper is focused on the application of Adaptive Nuerofuzzy Inference system (ANFIS) techniques in the model-based Fault Detection and Isolation (FDI). The objective of this study has been to create an online system for condition monitoring and diagnosis of specific faults for a Gas Turbine (GT) power plant. In order to study FDI and condition monitoring, accurate model of GT is needed. In this paper, the nonlinear Rowen's model is developed in Matlab/Simulink software to simulate the GT system behavior. Then, regarding the gain of artificial intelligence systems in FDI, the neurofuzzy inference system with capability of reliable learning and data approximating, is employed in developing the proposed FDI algorithm. In this paper, three types of faults have been considered, fault in the fuel flow rate, fault in the performance of turbine which affects the turbine exit gas temperature, and fault in the turbine which affects the turbine output torque. The results illustrate the effectiveness of the method in detecting and isolating the specified faults. Regarding the quality and the accuracy of the proposed algorithm, the method is introduced as the remarkable FDI methods of the stationary GT systems possibly extending to other similar applications.