bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal Parts Visual Inspection Based on Production Rules
Authors: Haider Sh. Hashim , Prabuwono Anton Satria , Siti Norul Huda Sheikh Abdullah
Published: October 2011

In manufacturing industry the automated visual inspection system (AVIS) is a method to inspect, classify and detect defects of various products. In the past, the tasks of inspection are carrying out by humans, machines or both. In this paper, we account for an AVIS model to classify mechanical parts in production line. It comprises two parts: hardware and software. The model uses a web-camera attached to an adjustable stand to capture various group of metal part images. The main objective is to develop an intelligent inspection tool based on image processing and production rules. It computes both the area and circularity of mechanical shapes as the features and hence classifies them according to ten categories such as screws, nuts, and bolts at different sizes. The result shows that the accuracy is 91.5% for group and 98.25% for individual classification of mechanical parts subsequently.
Designing and Fabricating of Low Cost Thermoelectric Power Generators
Authors: Seetawan Tosawat
Published: October 2011

Fossil fuel is the main energy resources of the world. About 80-90% of its primary energy need to supply by oil, coal, natural gas, and oil shale [1]. These energy resources will also be of importance in the future but non-renewable and cause problems to the environment as a result of their relatively high amount of carbon dioxide (CO2), carbon monoxide (CO), and other environmentally harmful emissions. We are investigating to look for alternative energy resources which are clean, safe, and long-term reliable. Thermoelectricity is one of the renewable energy resources that has been widely investigated and is expected to be feasible in the near future. Moreover, it is a clean energy generation, since it can directly convert heat to electrical energy by using non-polluting thermoelectric devices. These are reasons for the growing interest in further research and development of the thermoelectric technology. The search for new thermoelectric materials is important that the transition metal oxides were interested such as p-type Ca3Co4O9 [2-7] and n-type CaMnO3 [8-12]. There have been synthesized using different techniques in the form of powder and bulk. However, the doped metals have been expected to be one of the candidates for good thermoelectric materials, including thermoelectric module consists of two or more materials of p-type and n-type [13-15]. Recently, the thermoelectric module is also being used as the thermoelectric generators, thermoelectric coolers, etc. [16-17].
Neuro Fuzzy Modeling of Laser Beam Cutting Process
Authors: Pandey Arun Kumar , Dubey Avanish Kumar
Published: October 2011

Laser Beam Cutting (LBC) being a complex cutting process needs a reliable model for prediction of the process performance. This research work presents a modeling study of LBC process. A hybrid approach of Artificial Neural Network (ANN) and Fuzzy Logic (FL) has been used for developing the Kerf width model. The developed Neuro Fuzzy model of Kerf width has also been compared with Response Surface Methodology (RSM) based model and it has been found that the values of Kerf width predicted by the Neuro Fuzzy Model are more closer to the experimental values.
The Analysis of the Two-Wire Transmission Line in a Cavity with Apertures Illuminated by a Plane Wave Based on Electromagnetic Topology
Authors: Yu Qun , Wang Ya Di , Han Ji Hong , Kong Hong Shan , Zhang Yu Chen
Published: October 2011

By using electromagnetic topology (EMT) method, this paper discusses the issue of the electromagnetic field penetration through an aperture to a cavity and coupling to a two-wire transmission line in the cavity. By representing the electromagnetic field propagation path as “tube”, and combining with transmission line theory, this paper creates the Baum-Liu-Tesche (BLT) equation of radiation coupling. Then, by employing the BLT equation, the semi-analytic solutions of the load response of the two-wire transmission line in the cavity are obtained. Numerical examples are constructed to demonstrate the validity of this technique.
Determination of Mass Properties for the VX-SAT Communication Satellite
Authors: Alvarez Jose
Published: October 2011

The determination of a spacecraft’s mass properties is critical during its conceptual design phase. Obtaining reliable mass property information, early in the design of a spacecraft, could prevent design mistakes that can be extremely costly in the development process. The process of the determination of the mass properties consist in a systematic work, that include the taking part of all the sub systems or design teams that conforms the preliminary tasks for the design of the communications satellite. The VX-SAT project is a system engineering exercise, realized in the China Academy of Space Technology (CAST) like training for the future designs in communication satellites for the Bolivarian Agency of Space Activities (ABAE) in Venezuela. This paper aim to show an analysis of the procedures in the calculation of the mass properties in communication satellite using suitable software’s and the importance of the process to collect the mass budget information to get the more reliable results. Also includes an overview of the VX-SAT system, the preliminary design of the structure requirements and finally the methods used to the analysis of the general determination of the mass properties with its results.
Study on the Status of Offshore Oil Storage Technology and Non-Pollution Oil Storage Technology Underwater
Authors: Chu Xin Jie
Published: October 2011

With the rapid development of offshore oil and gas exploitation and production at marginal oilfields, production facilities of non-pollution oil storage underwater are sorely needed to reduce production costs. The paper gives a general outline of the modes of offshore oil Storage and the status of oil Storage technology underwater. Several modes of oil storage underwater on oil/water separation and replacement are discussed. The scheme on the monitoring system of non-pollution oil storage underwater is put forward. The study is of reference value for the development at offshore marginal oilfields.
New Approach to Salve Single Event Upsets Faults in Satellite Communications
Authors: Ghodratian Mahoomd , Masoomi Ashkan , Hamzehyan Roozbeh , Shirazi Najmeh Cheraghi
Published: October 2011

The encrypted satellite data can get corrupted before reaching the ground station due to various faults. One major source of faults is the harsh radiation environment. Single Even Upset (SEU) faults can occur on-board during encryption due to radiation. This paper presents a novel model to detect and correct Single Event Upsets in on-board implementations of the AES algorithm, which is based on Hamming error correcting code. From five modes of AES, CRT mode seems to be the best mode to encrypt satellite video and image links. A detailed analysis of the effect of SEUs on the imaging data during on-board encryption using the modes of AES is carried out. In this paper the impact of these faults on the data is discussed and compared for all the five modes of AES. A detailed analysis of the effect of SEUs on the imaging data during on-board encryption using the modes of AES is carried out.
Creep Analysis in Anisotropic Composite Rotating Disc with Hyperbolically Varying Thickness
Authors: Gupta Vandana , Singh Satya Bir
Published: October 2011

Steady state creep in a anisotropic rotating disc made of Al-SiCp composite having hyperbolically varying thickness has been investigated using Hill’s yield criterion. The creep behavior is supposed to follow the Sherby’s law in present study. The stress and strain distributions are calculated for different combinations of anisotropic constants. The change in the radial stress is not significant while the tangential stress is changed with the change in the material constants. The tangential strain rates are highest at the inner radius of the disc and then decreases towards the outer radius of the disc. The radial strain rate which is compressive in nature becomes tensile in middle of the disc for some specific values of anisotropic constants. The study reveals that the anisotropy has a significant effect on the creep behavior of rotating disc. Thus for the safe design of the rotating disc the effect of anisotropy should be taken care of.
Nonlinear Effects on Resonance Behaviour of Beams in Micro Scale
Authors: Nourbakhsh H. , Mohammadzadeh R. , Rafiee M. , Rafiee R.
Published: October 2011

Nonlinear free and forced oscillation of microscale simply supported beams is investigated in this paper. Introducing a material length scale parameter, the nonlinear model is conducted within the context of non-classical continuum mechanics. By using a combination of the modified couple stress theory and Hamilton’s principle the nonlinear equation of motion is derived. The nonlinear frequencies of a beam with initial lateral displacement are discussed. Equations have been solved using an exact method for free vibration and multiple times scales (MTS) method for forced vibration and some analytical relations have been obtained for natural frequency of oscillations. The results have been compared with previous work and good agreement has been obtained. Also forced vibrations of system in primary resonance have been studied and the effects of different parameters on the frequency-response have been investigated. It is shown that the size effect is significant when the ratio of characteristic thickness to internal material length scale parameter is approximately equal to one, but is diminishing with the increase of the ratio. Our results also indicate that the nonlinearity has a great effect on the vibration behavior of microscale beams.
A Comparative Study of Two Preconditioners for Solving 3D Inviscid Low Speed Flows
Authors: Hejranfar Kazem , Moghadam Ramin Kamali
Published: October 2011

In the present study, two preconditioners proposed by Eriksson, and Choi and Merkel are implemented on a 3D upwind Euler flow solver on unstructured meshes. The mathematical formulations of these preconditioning schemes for the set of primitive variables are drawn and their eigenvalues and eigenvectors are compared with each others. A cell-centered finite volume Roe's method is used for discretization of the 3D preconditioned Euler equations. The accuracy and performance of these preconditioning schemes are examined by computing low Mach number flows over the ONERA M6 wing for different conditions.
Research on Design for Testability of Marine Diesel Engine
Authors: Zhou Ping , Liu Dong Feng
Published: October 2011

The rapid development of manufacturing industry making the pursuit of equipment performance increasingly demanding. Proceeded from design, considering testing and diagnosis problems from whole system and life cycle is an effective way to avoid major accidents and reduce the cost of maintenance, therefore, testability is widespread concerned. In this paper, taken marine diesel engine as research object, analyzed its necessity and feasibility of design for testability (DFT), through fully study of marine diesel engine’s testability characteristics, introduced multi-signal model to analysis marine diesel engine’s lubrication system testability, then advanced improvements for its testability, it can detect and isolate all faults of lubrication system, which provided a reference guide to marine diesel engine’s manufacturing.
Reliability Analysis of a Small Pneumatic Cylinder Life
Authors: Zhang Jun Zhao , Wang Cong Ling , Fang Xue Fa
Published: October 2011

The reliability of the pneumatic cylinder was investigated by routine life test. The results show that the failures of the pneumatic cylinder can be described as a Weibull distribution and fatigue fracture of the aluminum end cap and the head of install bolt is the major failure for the pneumatic cylinder. The pneumatic cylinder life distribution parameters were estimated by the median rank method in combination with maximum likelihood method. The distribution model for the reliability of the pneumatic cylinder was also proposed here.
Effects of Aeroelastic Nonlinearity on Flutter and Limit Cycle Oscillations of High-Aspect-Ratio Wings
Authors: Eskandary Keivan , Dardel Morteza , Pashaei Mohammad Hadi , Kani Abdol Majid
Published: October 2011

In this study aeroelastic characteristics of long high aspect ratio wing models with structural nonlinearities in quasi-steady aerodynamics flows are investigated. The studied wing model is a cantilever wing with double bending and torsional vibrations and with large deflection ability in according to Dowell-Hodges wing model. This wing model is valid for long, straight and thin homogeneous isotropic beams. Aerodynamics model is based on quasi-steady aerodynamic which is valid for aerodynamic flows in low velocity and without wake, viscosity and compressibility effects. The effect of different parameters such as mass ratios and stiffness ratios on flutter and divergence velocities and limit cycle oscillation amplitudes are carefully studied.
Study on the Addition of Viscous Agents to Fish-Boat-Fuel in Real Ship Trials
Authors: Yang Tsun Lirng
Published: October 2011

This study adopted a new formula fishing-boat fuel which is based on the existing fishing-boat-fuel A (FBFA) with the addition of viscous agents (RDS0.5, PFO0.5) in two different proportions. FBFA, RDS0.5 and PFO0.5, respectively are tested in three real-scale fishing boats. During the actual ship trial, the engine operating conditions, engine fuel oil consumption, horse power output and navigation speed were assessed and recorded. Furthermore, fuel emissions were sampled and analyzed, fishing-boat diesel engine performance was assessed and differences in exhaust composition were compared. The results showed that the three new viscous agents fules used lack abnormal vibration and noise, and have similar output status in terms of engine operational performance. At the same boat, the fuel oil consumption rates were similar between the new formula and FBFA. Moreover, analysis of contamination displayed that RDS0.5 particulate matter (PM) content was less than that of FBFA. Consequently, RDS0.5 appears to cause less engine wear. Additionally, the exhaust emission analysis results identified RDS0.5 as the best fuel for the engine. Futhermore, regarding pollutant emissions, including CO, CO2, NOx, PM, PAHs, only CO emissions are slightly higher than for FBFA. However, the CO emission value does not exceed exhaust emission standards of the U.S. Environmental Protection Agency (EPA). It is remains within the allowable value range. RDS0.5 should have practical value.
Absorption and Evaporation Mass Transfer Simulation of a Droplet by Finite Volume Method and SIMPLEC Algorithm
Authors: Torfi S. , Nejad S.M. Hosseini
Published: October 2011

In this paper, a numerical model is developed to simulate single droplet heat and mass transfer in a two-pieces solution with a saturated solvent vapor environment. Finite volume method and transient SIMPLEC algorithm in spherical coordinates system used for simulation. For simulation of the mass transfer, dimensionless equations of motion, heat transfer and mass transfer (based on mass ratio) are solved simultaneously. All the thermodynamic and transitional solution properties have been considered as a function of temperature and concentration. Verification of method is done by compare these numerical results with analytical and numerical analysis of other studies. Evaporation, absorption and condensation contours in a water droplet at uniform temperature at superheated water vapor and Distribution of Droplet's Surface Temperature, Constant Temperature and concentration lines as the modeling results are presented. The results are shown that 0.5% increase of concentration of droplet cause increase 8 degree C of mean temperature of droplet.
Sequencing Mixed-Model Assembly Line under a JIT-Approach‌
Authors: Tavakoli Neda Beitollahi , Fattahi Parviz
Published: October 2011

Mixed-model assembly line is known to be a special case of production lines where various and different models of the same products are inter-mixed to be assembled on the same line. Using mixed model assembly line involves not only the traditional problems of assembly line design (i.e., determining the line cycle time, the number and sequence of stations of the line, and balancing the line) but also determining the sequence in which products will be scheduled for assembly. In each station, some components are assembled in the final products. Under just in time (JIT) approach; an objective is to have a fairly constant usage rate for each component going into final assembly to facilitate the use of Kanban or other JIT shop-floor systems. In this paper, a mixed approach, the sequencing mixed-model assembly line problem with a JIT-supply of required materials, ‌is studied and a mathematical model is proposed for solving it. The results are compared with a traditional approach. Some experiments are used to evaluate the performance of the proposed model.
Numerical Study on Plasma-Based Control of Flow over a Square Cylinder
Authors: Kim Dong Joo , Kim Jungwoo
Published: October 2011

Over the past decade, a lot of attention has been paid to plasma actuators because they are useful tools for flow control. Previous successes with plasma actuators include drag and noise reductions from a circular cylinder, one of representative bluff bodies, mainly through separation delay. However, to the best of authors’ knowledge, no attempt has been made to examine its capability to control square cylinder wake with fixed separation points. The purpose of this study is to numerically investigate whether or not the square cylinder wake can be controlled by means of plasma actuators. In particular, a linear plasma synthetic jet actuator is adopted and attached to the rear side of the cylinder. In this study, we use an immersed boundary method combined with an empirical plasma model for plasma-based flow control. The present method is second order accurate in time and space. Results show that the wake behind the square cylinder can be controlled effectively when the plasma-induced force is strong enough. With the plasma actuator on, the mean drag is reduced and the Karman vortex shedding is alleviated because the induced jet increases the base pressure and prevents the separating shear layers from interacting with each other.
Intelligent Parking Method for Trucks in Presence of Fixed and Moving Obstacles Randomly
Authors: Rohani Javad , Sharafi M. , Zare Assef
Published: October 2011

A Fuzzy approach to backward movement control for trucks in a dynamic environment is presented in this paper. The approach is then extended and employed for conditions where Obstacles randomly are placed on the truck pathway. In the first case, Obstacles randomly are assumed to be fixed, while the second condition includes moving Obstacles randomly through which the truck should be directed toward the parking dock. The method is designed in a way to be used in conditions with infinite number of Obstacles randomly at arbitrary places. In any case, to find the parking dock, the truck movement must be adapted to that of Obstacles randomly. In the present paper, two separate fuzzy controllers are used for directing the truck: one for finding the target, and the other for avoiding the Obstacles randomly. While there is no Obstacles randomly around, the target finder controller is in use; and in the cases where the truck gets close to Obstacles randomly the Obstacles randomly avoider controller is activated. The proposed method is employed for parking a truck model through fixed and moving Obstacles randomly.
Adaptive Dynamic Surface Control for a Parametric Strict Feedback System with Actuator Failures
Authors: Kendrick Amezquita S. , Yan Lin , Butt Waseem Aslam
Published: October 2011

An adaptive dynamic surface control scheme for actuator failures compensation in a class of nonlinear system is presented. Radial basis function neural networks (RBF NNs) are incorporated into our controller design, for approximating the nonlinearities around the known nominal model. The RBF NNs compensate the system dynamics uncertainties and disturbance induced by actuator failures. The closed-loop signals of the system are proven to be uniformly ultimately bounded (UUB) by Lyapunov analysis. The output tracking error is bounded within a residual set which can be made small by appropriately choosing the controller parameters. We show the effectiveness of our approach by simulating the longitudinal dynamics of a twin otter aircraft with half portion of the elevator failing at unknown value and time instant.
PID Parameters Tuning for the Control of Nonlinear Systems Using Measure Theory
Authors: Zare Assef , Kamyad A.V.
Published: October 2011

This paper presents a new approach for tuning PID controller parameters in the control of nonlinear systems. The design is based on optimal tracking of step response for nonlinear systems. The problem is first restated as a non linear optimal control infinite horizon problem, then with a suitable change of variable, the time interval is transferred to the finite horizon [0 1). This change of variable, poses a time varying problem. This problem is then transferred to measure space, and it is shown that an optimal measure must be determined which is equivalent to a linear programming problem with infinite dimension. Then, using finite horizon approximations, the optimal control law as piece wise constant function is determined. Finally, PID controller parameters are Determined using the optimal control law. Simulations are provided to show the effectiveness of the proposed methodology.
Novel Approach for Nonlinear Maneuvering Target Tracking Based on Input Estimation
Authors: Rahmati Hodjat , Khaloozadeh Hamid , Ayati Moosa
Published: October 2011

In this paper, a new method for maneuvering target tracking (MTT) based on nonlinear input estimation (IE) is innovated and is employed for tracking of maneuvering targets. Proposed method augments the states and unknown inputs (maneuvers) in a higher order state space realization and estimates both of them simultaneously. The concurrent estimation of states and inputs eliminates the maneuver detection delay which is popular in the conventional IE methods. The proposed method has excellent performance for both maneuvering and non-maneuvering stages. Also, a model with highly nonlinear dynamics for maneuvering targets is given and is used in the numerical simulations to analyze the performance of the proposed maneuvering target tracking method. Furthermore the proposed method is compared with a conventional IE method and the simulation results show the effectiveness of the proposed method.
An Investigation on the Sensitivity of Limit Cycle Oscillations for Detecting Damage in an Aeroelastic Panel
Authors: Eftekhari S.A. , Bakhtiari-Nejad F. , Dowell E.H.
Published: October 2011

There are many nonlinear systems used in engineering which require damage detection. For such systems, nonlinear damage detection methods may be useful. In this paper, a novel method is introduced that uses limit cycle oscillations that arise once the bifurcation (flutter) boundary is exceeded and shows greater sensitivity for damage detection versus linear damage detection techniques. Another advantage of this method is that it can be used for health monitoring of linear or nonlinear systems. Here a nonlinear aeroelastic panel is considered as a model to show the capabilities of the proposed damage detection technique. Also Proper Orthogonal Decomposition is used to find the number of independent damage locations in the panel.
Crushing Behavior of Composite Hexagonal Ring System
Authors: Mahdi Elsadig , Hamouda A. M. S.
Published: October 2011

An extensive experimental investigation of inplane crushing of composite hexagonal ring system between platens has been carried out. Woven roving glass/epoxy hexagonal ring system with different angles and arrangement were employed. The rings angles are varying between 45 and 70°. The wet winding process was used to fabricate the woven E-glass fabric /epoxy specimens. Four layers of woven E-glass fabric/epoxy wrapped over wooden mandrel to get thickness of about 3 mm. The composite hexagonal tubes were then cured at room temperature (32oC) for 24 hours to provide optimum hardness and shrinkage. Repeatability of the results was ensuring by performing the experiments on three identical specimens. Typical histories of their crushing mechanism are presented. Behavior of ring as regards the initial crushing load, post crushing load, energy absorbed and mode of crushing has been presented and discussed. Results showed that the crush failure loads and energy absorption capability are greatly affected by the hexagonal ring geometry, arrangement and loading conditions. As the ring angle increases the energy absorption capacity increases. Composite hexagonal ring with 70 degree exhibited the highest energy absorption capability among tested specimens. It is also found that energy absorption capability for systems crushed in-plane X2 higher than X1.
Measurement of Multiple Mechanical Properties of Fabrics in One Test
Authors: Du Zhao Qun , Zheng Gang , Shen Hua , Yu Weidong
Published: October 2011

The compressibility, bending, weight, friction, tensile and shear properties of wool fabrics and yarns are of vital importance in the hung shape and virtual fitting of end-use textile products. A new apparatus has been developed for characterizing the above mechanical properties of wool fabrics and yarns through a single testing, and the corresponding modeling analysis for compressing, bending, weighting, friction, stretching and shearing properties were conducted and the corresponding characteristics were all measured just through one pulling out testing based on a three-point bending in principal. The compressing measurements for fabric and transversal cross-section yarn were conducted and could obtain the thickness under certain pressure and the low load and thickness curve. The bending modeling for small deflection was developed and adapted to the nonlinear relationship of bending moment and curvature, and the governing differential equation for bending rigidity was found. The weight of fabric in Gram per square meter and the linear density of yarn in Tex per unit length were both effectively and accurately calculated. The friction method was developed based on the Amonton’s Law, and the static and dynamic frictional coefficients were found. The tensile and shear properties under low stress were investigated and the corresponding characteristics, such as elastic modulus and shearing modulus, were obtained. Moreover, the fuzzy clustering analysis for handle of fabrics or yarns was utilized to classify and further verify the measured fabrics or yarns based on the mechanical properties mentioned above. Thereof, the comprehensive handle system for fabrics and yarns (briefly named CHS-FY) was necessarily self-designed and utilized to characterize the mechanical properties, which played a crucial role in quickly classifying the fabrics and yarns with different style. Meanwhile, the verifications of the comprehensive handle system for fabric and yarn was conducted, and indicated that there were in good agreement between theoretical and experimental results of mechanical properties of wool fabric and yarn, and showed that there existed high accuracy in classification with the fuzzy clustering analysis. Thereby, the comprehensive handle system for wool fabrics and yarns is effective and accurate in measuring the compressibility, bending, weight, friction, tensile and shear properties and fast classifying the handle of wool fabrics and yarns.
Analysis of an Engine Mounting Structure of an Aircraft with the Purpose of Accurate Adjustment
Authors: Ebrahimi Mehran , Niaki Sina Amini , Salarieh Hassan
Published: October 2011

In airplanes, engine mounting structures have two primary performances: 1-They sustain all loads which engines produces or those which are exerted on engines in different maneuvering conditions. 2-They make the thrust load and the centric line of its containing cabin concentric [1]. In this paper, analysis of a mounting engine structure with the purpose of the accurate adjustment of the engine in its cabin is presented. Some sample diagrams, which introduced ideal adjustment angles for a specific aircraft, is proposed. These diagrams are obtained with the help of a MATLAB program that can be used for any dimension of the engine and cabin. Therefore, with the aid of these diagrams or this code, the time of adjustment the engine in its cabin will be decreased so much.
A Numerical Study of the Effect of Pressure on Propulsive Droplets Sizing in a Duct by KIVA-3V Code
Authors: Doustdar Mohammad Mahdi , Mojtahedpoor Mohammad
Published: October 2011

The size of fuel propulsive droplets is one of the effective parameter in improvement of the mixture of air and fuel as well as combustion. The effects of Pressure on the average diameter of fuel propulsive droplets sizing and effective mass fraction in a duct are numerically investigated in the present paper. We named the mass of fuel vapor inside the flammability limit as the efficient mass fraction. The inlet pressure of entrance airflow is varied as 1, 2, 3, 4 and 5 (atm) to examine its effects on the fuel droplets and fuel/air mixing phenomena. As well, by growing the entrance air flow velocity from 36 to 50 (m/s) we have repeated this test again, which provides worthwhile information for the combustor design work. To fulfill the calculations a modified version of KIVA-3V code which is a transient, three-dimensional, multiphase, multicomponent code for the analysis of chemically reacting flows with sprays, is used.
Combustion Properties of Norwegian Biomass: Wood Chips and Forest Residues
Authors: Houshfar Ehsan , Sandquist Judit , Musinguzi Wilson Babu , Khalil Roger A. , Becidan Michaël , Skreiberg Øyvind , Goile Franziska , Løvås Terese , Sørum Lars
Published: October 2011

Flue gas emissions and particle size distribution were investigated during combustion experiments of wood, forest residue and mixtures of these two. The combustion experiments were carried out in a grate fired multi-fuel reactor with and without air staging at stable operation conditions and constant temperature of 850 °C. The overall excess air ratio was held at 1.6, and the primary excess air ratio was 0.8 during air staged experiments. NOx emissions are reduced by air staging. Fly ash particle concentration of forest residues in the flue gas is lower than wood. Aerosols number increased in the staged experiments for fuel blends.
Effect of Acid Treatment on Silica-Titania Aerogel as Oxidative-Acidic Bifunctional Catalyst
Authors: Lee Siew Ling , Nur Hadi , Wei Soo Chien
Published: October 2011

Acid treatment using H2SO4, HCl and H3PO4 has been carried out in an attempt to improve catalytic performance of silica-titania aerogel. X-ray diffraction results showed the amorphous structure of the aerogels remained after the acid impregnation and calcinations steps. Hammert analysis revealed these acid modified silica-titania aerogels were superacids with pKa < -14.52. Different Ti species was observed in the samples upon the acid treatment. As compared to silica-titania aerogel, Lewis acidity increased remarkably in HCl treated sample without formation of any Brønsted acid site. Meanwhile, H2SO4 and H3PO4 treated samples possessed both Lewis and Brønsted acid sites. The catalytic performance of these samples was evaluated through a consecutive transformation of 1-octene to 1,2-octanediol through the formation of 1,2-epoxyoctane using aqueous hydrogen peroxide as oxidant.
Investigation of Nonlinear Acoustic Effects in Two-Dimensional Open Cavity Flow
Authors: Ebrahimi Mohammad
Published: October 2011

The aeroacoustic field generated by incompressible airflow over a two-dimensional open cavity is investigated. The main objective of this study is to determine the role of nonlinearity on this phenomenon. To this end the cavity aeroacoustics is investigated with both linearised and nonlinear approaches. Both free-air and confined cavity geometries are investigated and it is shown that nonlinearity does not affect the aeroacoustic field much. The solutions are verified for grid and computational domain independency. It is concluded from this study that nonlinear aeroacoustic phenomena are very weak in external incompressible flows and low-cost linearised formulations can easily be applied in such cases.
Unsteady Compressible Flow over Heaving Bodies Using an Implicit RANS Solver
Authors: Kumar K. Siva , Sajjan Sharanappa V.
Published: October 2011

Unsteady Reynolds-Averaged Navier-Stokes computations are presented for the flow over a pure plunging aerofoil and a plunging wing. The implicit RANS solver used for obtaining time-accurate solution is based on implicit finite volume nodal point spatial discretization scheme with dual time stepping. Baldwin and Lomax turbulence model has been used for the turbulence closure. The results are obtained in the form of aerodynamic coefficients, thrust coefficient and propulsion efficiency for two different cases over the aerofoil and wing and are compared with available literature.
Failure Analysis of Low Pressure Evaporator Tubes in a Typical Combined Cycle Power Plant
Authors: Nematollahi M. , Rezaeian M.
Published: October 2011

Flow-induced corrosion is one of the most prevalent tube damage mechanisms in steam generators of power plants. In this study, tube failure of a steam generator in Fars Combined Cycle Power Plant is evaluated. In addition to analysis of the measured tube thicknesses and the failure statistics data, computational fluid dynamic (CFD) methods are used to simulate flow distribution inside and outside of the tubes in one header of the low pressure circuit of the plant steam generator. The results show that regarding the created two-phase flow pattern inside the tubes, the droplet impingement erosion is the main source of tube failures in the bending areas where the extrados surface of the tubes are partially prone to the droplets. The results are useful for modifying the design of the steam generator from different viewpoints such as, optimal design for appropriate configuration of downcomer, header and footer and tube bending. Also, selecting suitable material for the steam generator tubes and implementation of protective coating in risky areas would benefit from the present results.
Reynolds Study of the Flow Induced Noise
Authors: Singh Deepesh Kumar , Bandhyopadhyay G.
Published: October 2011

2D Large Eddy Simulation turbulence model coupled with Ffowcs-Williams-Hawkins model and Boundary Element Method is used to perform a study of the effect of the Reynolds number on the broadband noise emitted due to the incompressible fluid structure interaction. The method is then used to calculate the broadband noise emitted by the aerodynamic flow over different shape bodies having same cross-sectional area with the intent to know the most suitable cross sectional geometry of the fuel manifolds in the aircraft engine afterburner in terms of minimum noise emission. The results obtained suggests that a 5dB benefit in sound emission could be obtained by the halving the diameter of the circular cross-section used for the fuel manifolds, to make them elliptical keeping cross sectional area constant.
Pressure Corrections for the Potential Flow Analysis of Kelvin-Helmholtz Instability
Authors: Awasthi Mukesh Kumar , Asthana Rishi , Agrawal G.S.
Published: October 2011

The present paper deals with the study of viscous contribution to the pressure for the viscous potential flow analysis of Kelvin-Helmholtz instability of two viscous fluids. Viscosity enters through normal stress balance in the viscous potential flow theory and tangential stresses for two fluids are not continuous at the interface. Here we have considered viscous pressure in the normal stress balance along with the irrotational pressure and it is assumed that the addition of this viscous pressure will resolve the discontinuity between the tangential stresses and the tangential velocities at the interface. The viscous pressure is derived by mechanical energy equation and this pressure correction applied to compute the growth rate of Kelvin-Helmholtz instability. A dispersion relation is obtained and a stability criterion is given in the terms of critical value of relative velocity. It has been observed that the inclusion of irrotational shearing stresses stabilizes the system.
Effect of Building Height on Energy Consumption of Radiator and Floor Heating Systems
Authors: Golkarfard Vahid , Talebizadeh Pouyan , Salmanzadeh Mazyar
Published: October 2011

Buildings are one of the most important energy consumers in the world. High temperature gradients in heating systems can cause the increase of heat loss of the envelopes during the cold season and consequently increase the energy consumption. Floor heating systems has shown that they can generate lower temperature gradients in compare with other convective heating systems. In present study, the CFD simulation is done for a 3-D room and the required energy to achieve the thermal comfort in a room is calculated. The height of the room is changed and the energy loss of the room is calculated for both systems. Results showed that as the height doubles, the wall heat loss for radiator system almost doubles but for the floor heating system it was about 60 percent. This impressive result can recommend the floor heating systems for working areas with tall ceilings.
Dispersive Correction to Casimir Force at Finite Temperature
Authors: Teo Lee Peng
Published: October 2011

We study the dispersive correction to the finite temperature Casimir force acting on a pair of plates immersed in a magnetodielectric medium. We consider the case where both the plates are perfectly conducting and the case where one plate is perfectly conducting and one plate is infinitely permeable. Although the sign and the strength of the Casimir force depend strongly on the properties of the plates, it is found that in the high temperature regime, the Casimir force has a classical limit that does not depend on the properties of the medium separating the plates.
An Aerothermodynamic Design Approach for Scramjet Combustors and Comparative Performance of Low-Efficiency Systems
Authors: Sarosh Ali , Feng Dong Yun , Adnan Muhammad
Published: October 2011

This paper is aimed at development of an integrated approach based on analytical and computational aerothermodynamics for the special case of design of a 75% (low process-efficiency), hydrogen-fuelled, constant area combustor of a hypersonic airbreathing propulsion (HAP) system thereafter undertaking study of two types of HAP systems. The results of configurational aerothermodynamics implied that the most appropriate constant area configuration had a 30 degrees downstream wall-mounted fuel injector with a single acoustically stable cavity placed downstream of the fuel injection point. Moreover for identical flow inlet parameters and system configurations at lower levels of thermodynamic process efficiencies, the constant combustor-area (i.e. Scramjet 1) engine is superior in its performance to the constant combustor-pressure (i.e. Scramjet 2) engine for all values of fuel-air ratios.
Analysis on Characteristics of Heavy Vehicle Electrical Cooling Fan with CFD and Motor Test Results
Authors: Kim Joo Han , Jung In Soung , Hur Nahmkeon , Kim Wook
Published: October 2011

Heavy vehicle cooling fan is seen as one of the main means of vehicular fuel efficiency reduction. This is becoming a major factor in city noise, and the necessity of electromagnetic technical development is very great. CFD method could replace experiment for development of heavy vehicle cooling fan, but it cannot be applicable to some of real design stage because of limitation that rotating speed must be set as boundary condition. In this article, we developed a new algorithm in which we are able to determine both static pressure and rotating speed through setting up the only voltage as a boundary condition with motor performance test results
Turbulence Pattern in Triangular Cylinder
Authors: Parthiban V. , Russelle Ashwin
Published: October 2011

In order to predict a turbulent flow around a triangular cylinder a high Reynolds number of 45000 is done in the numerical simulation. In this simulation both steady and unsteady vortex shedding is predicted and various time steps. The numerical method used in this simulation is Reynolds Stress model. For steady and unsteady solution velocity contours and velocity vector plots is to be predicted for the vortex shedding behind the triangular cylinder.
Research of the Key Techniques of Monitoring On-Orbit Docking for BLRU
Authors: Ni Wei , Xiong Zhao , Xiong Qian , Tan Ning , Yuan Xiao Dong , Xie Zhi Jiang , Zheng Wan Guo
Published: October 2011

This assay analyzes the docking of BLRU for the SG-Ⅲ Laser Facility, where centering and collision issues are pointed out as the key technologies for BLRU docking monitoring. The centering technology mainly transforms the three-dimensional problem into two-dimensional one, adopting the characteristic of machine version capturing to analyze the position and posture of BLRU. The collision monitoring technology mainly takes advantage of the principle that power is generated in the collision during the process of assembly and calibration. Monitoring the forces from each direction, the degree of indirect response to the collision, returning feedback to the docking platform after measurement data is analyzed, and amending the docking trajectory of the BLRU in time can achieve the light collision docking during the full process of BLRU.
Design of a Remote Mine Gas Concentration Detector
Authors: Xu Su
Published: October 2011

In this paper, a remote mine-gas concentration real-time detecting system is realized, which is cored at the MSP430F247 single chip and the Siemens TC35GSM module. The author introduces the system structure, functional principle and specific implementation scheme in details. Besides, the real-time collection of gas concentration, high-speed and accurate analysis on the data, setting and exceeding standard alarm of gas concentration, remote date transportation and good human-computer interaction displaying function can be realized through the making and debugging of the prototype.
Design and Fabrication of 3D Syskevis Metrisis
Authors: Arunachalam M. , Padmanaban Kailash , Asvin K. , Kumar R. Senthil , Vijaya Ramnath B.
Published: October 2011

This paper focuses on measuring of an object’s three axes dimensions (X Y&Z) simultaneously. The instrument is called “3D syskevis metrisis” and this name has been derived from Greek words which means 3D measuring device. This instrument has a least count of 0.02mm and has the range of 15cm in all the three axes (X, Y & Z respectively). The object to be measured is not moved after it is initially placed on the base part of the instrument and there is no chance for error due to the mishandling of the object because the DOF (degree of freedom) of the object is arrested with the syskevis scale and the time for measuring the object is less when compared to the time taken by a Vernier caliper. The main advantage of this instrument is its low cost which is around RS8500.Thus by using this instrument we can measure the dimensions of small objects without moving the object after it is placed on the instrument with high accuracy and low cost.
Design and Development of Swarm Robots for Security Applications
Authors: Thangavel M. , Raghavan S. , Raviprakash R. , Raja V. Rubesh , Manickam Shankar
Published: October 2011

In this paper, a robot design suitable for swarm based security system is presented. First, a possible layout for swarm based security system is conceptualized and literatures related to mobile robot design are reviewed. Second, a set of conceptual designs for the swarm robot are evolved and discussed. Third, expressions are arrived for weight, rolling resistance, obstacle crossing ability and amount of slip based on robot geometric parameters. Fourth, the obstacle crossing ability for rear wheel driven and rear wheel driven robots are investigated. Fifth, a prototype is made and the analytical expressions arrived are verified experimentally. Sixth, the drive power required for the direct drive robot is determined. Finally, based on weight, number of actuators, type of drive, type of wheels used, rolling resistance, and obstacle crossing ability an appropriate robot design is selected.
Multidisciplinary Design Optimization Approach for a Small Solid Propellant Launch Vehicle Conceptual Design Using Hybrid Simulated Annealing
Authors: Ebrahimi Masoud , Roshanian Jafar , Barzinpour Farnaz
Published: October 2011

Multidisciplinary Design Optimization (MDO) of a two-stage Small Solid Propellant Launch Vehicle (SSPLV) by simulated annealing (SA) Method is investigated. Propulsion, weight, aerodynamic (geometry) and 3degree of freedom (3DOF) trajectory simulation disciplines are used in an appropriate combination. Suitable design variables, technological-functional constraints and minimum launch weight objective function are considered. To handle constraints augmentation of constraints to cost using penalty coefficients are used. Results are compared with gradient-base method that shows the ability of SA to escape local optimums.
Effects of N2 Pressure on Properties of Titanium Nitride Films by Filter Cathodic Vacuum Arc for Bipolar Plates in PEM Fuel Cells
Authors: Pejchang D. , Medhisuwakul M. , Sansongsiri S.
Published: October 2011

This research is aimed to synthesize titanium nitride (TiN) thin films on stainless steel 304 using metal vacuum arc surface coating technique. A titanium rod is used as cathode. Plasma is generated by applying the arc pulse voltage of 450 V between the electrodes in N2 atmosphere. The pressure of N2 is varied from 10-5 to 10-3 torr when compare with uncoated-stainless steel 304. The bias voltage for substrate is -1 kV. Then the properties of the films are investigated. Firstly, microstructures of TiN thin films are indentified by X-ray diffraction method (XRD) and the cross-section scanning electron microscopy (SEM) is used to measure the thickness. Secondly, the corrosion resistance is examined by electrochemical test in 1 M H2SO4 solution at 25°C. The electrical resistivity is analyzed by interfacial contact resistance measurements.
Design and Fabrication of Floor Conveyor
Authors: Srinivasan L.
Published: October 2011

In most of the companies heavy loads were moved either with help of cranes or conveyors. The conveyors are cheaper and it is suitable for small scale industries. These conveyors are constrained and can move the load in only one direction. In this project an effort has been put forth to design a multidirectional conveyor with help of ball bearings which can handle the load at different directions. Floor conveyor consists of ball bearings & shaft that makes the load to move at any directions. In olden days logs were used to move heavy loads from one place to another we developed those concept further and found conveyors, further improvement leads to the floor conveyor with multidirectional movement. Multidirectional is achieved by amalgamation of two ball bearings which is connected by a small shaft.