bluuebunny/crossref_metadata_2025 huggingface dataset:
Failure Pressure Estimation of Corroded Pipeline with Different Depths of Interacting Defects Subjected to Internal Pressure
Authors: Ahmad Azmy Ariz , Karuppanan Saravanan , Wahab Azmi Abdul
Published: September 2013

Pipelines are one of the most reliable and safest ways to transport oil and gas from one location to another. However, if not handled and maintained properly, they will cause major destruction should one of these pipelines burst. A pipeline which has oil or gas flowing through it will be subjected to internal pressure due to the flow of the oil or gas. Furthermore, the chemical composition of the oil and gas acts as a corrosive agent towards the pipeline. The corrosion eventually becomes defects thus compromising the pipeline integrity. In addition, if two defects are close enough, they are treated as interacting defects. In this work, the pipeline integrity was first calculated using DNV RP-101 codes. After calculating the maximum operating pressure for the pipeline using the codes, Finite Element Analyses using ANSYS were carried out to simulate and model the pipeline with the interacting defects. The maximum operating pressure given by the FEA was then compared to the DNV codes. We found that despite consistency between DNV codes, the FEA analysis showed that geometry plays an important part in determining the values of failure pressure. The FEA analysis showed that by increasing the ratio of depth between the interacting defects, the failure pressure decreases. This was likely because defects of larger depths are more likely to fail at lower pressures. This contradicts the results obtained from DNV codes where the failure pressure is constant for the same effective defect depth over thickness, (d12/t)*.
Fundamental Technique of Pre-Blending of Bio-Matrix with Commercial HDPE
Authors: Rus Anika Zafiah Mohd , Sulong Nurulsaidatulsyida
Published: September 2013

The effect of bio-polymer as bio-matrix material with HDPE for the blending process is described in this study. 10%, 20%, 30%, 40% and 50% of bio-polymer was added to the HDPE and then blended by using Brabender Plastograph machine using mixer and roller screw and the test specimens were prepared by injection moulding. The compatibility of the origin bio-polymer (VOP), HDPE and the bio-matrix of bio-polymer/ HDPE (BioPE) were observed during the injection moulding process. Dumbbell shape of tensile test specimens were produced according to ISO 527-2 (5A) from the injection moulding process. Mixing process was successfully conducted based on two different matrix which is lab scale bio-polymer and production of commercial thermoplastic materials.
The Influence of Bath Concentration on Particle Size of Cobalt Nanoparticles
Authors: Resali Nor Azrina , Abdullah Wan Normimi Roslini , Hyie Koay Mei , Kalam Anizah , Nik Roselina N.R. , Mardziah C.M.
Published: September 2013

Cobalt nanoparticles have been widely used in magnetic storage media application. This study reports the characteristic and properties of Cobalt (Co) nanoparticles due to the effect of different bath concentrations. The Co nanoparticles were coated on the stainless steel substrate using different molar concentrations (M) of 0.05 M, 0.075 M and 0.1 M, respectively. The coating was done using electrodeposition method. Interestingly, the sphere particles surrounded by flakes were only found in the Co nanoparticles prepared in 0.075 M. This structure exhibited the smallest particles size, which is 83 nm. Besides, the nanoparticles also had the highest microhardness if compared to the Co nanoparticles prepared in 0.05 M and 0.1 M. The Co nanoparticles prepared in other concentrations were irregular structure without flakes. The polarization curves for all the nanoparticles showed the active behaviour without any distinctive to passivation. However, the corrosion rate of the sample prepared in 0.075 M was the lowest; 42.51 mpy compared to the other samples prepared in 0.05 M and 0.1 M, which were 176 mpy and 223.3 mpy, respectively. Hence, it was found that the bath concentrations affect the particle size of as-synthesized Co nanoparticles and finally changed the properties of final product.
Mechanical Properties of Aluminium Foam by Conventional Casting Combined with NaCl Space Holder
Authors: Mohd Razali Razmi Noh , Abdullah Bulan , Muhammad Hussain Ismail , Ahmad Umi Kalsom , Idham M. F. , Ramli Abdullah
Published: September 2013

The purposes of this study were to determine the correlation of the aluminium foams mechanical properties in terms of the effect between its density and porosity as well as between its compressive strength and energy absorption of aluminium foam produced by space holder technique. The space holder used was NaCl particle with three different sizes and conditions. The space holders were completely filled the cavity prior pouring of molten aluminium by CO2 sand casting. Then, the samples underwent machining process to remove surface imperfection after casting, followed by water leaching in ultrasonic cleaner to remove the space holder. The higher the porosity, the lower the compressive strength but then again it acts as good energy absorption. Aluminium foam using NaCl size range of 10-15 mm has the highest energy absorption.
Storage Modulus Analysis of Kenaf Fibre Reinforced Epoxy Composites
Authors: Abdullah Abdul Hakim , Alias Siti Khadijah , Latip Syazuan Abdul , Yunus Syarifah
Published: September 2013

This article presents the storage modulus analysis of kenaf fibre composites that reinforced by two different epoxy matrix systems, named epoxy A and epoxy B. These epoxies are commercially available in Malaysia and been used as a polymer matrix in composite research. Composites were made from hand lay out technique and undergo storage modulus evaluation by using dynamic mechanical analysis (DMA). Fibre content ratios were found to affect the storage capacity in both reinforced epoxy system. However, the addition of 45% kenaf fibre volume ratios reinforced into Epoxy A composites exhibits only week improvement as compared to its rival. The possibility of causes might be attributed to the week interfacial between fibre and matrix.
Fracture Toughness of Nanomodified-Epoxy Systems
Authors: Jumahat Aidah , Soutis Constantinos , Nurulnatisya Ahmad , Wan Mohamed Wan Mazlina
Published: September 2013

The effect of nanosilica, multiwalled carbon nanotubes (MWCNT) and montmorillonite (MMT) nanoclay on critical stress intensity factor and critical energy release rate of Epikote 828 epoxy polymer was studied. Fracture toughness tests were conducted on three types of nanocomposites which contain 5-25 wt% nanosilica, 0.5-1 wt% MWCNT and 1-5 wt% MMT nanoclay. The compact tension specimens of 9 mm initial crack length were fabricated and tested in tension. It was found that, the load at crack growth initiation FQfor all nanomodified polymer systems was higher than that of the neat epoxy. Hence, the presence of nanosilica, carbon nanotubes and nanoclay improves the critical stress intensity factor and critical energy release rate of the polymer. For the nanoclay-modified epoxy system, the degree of enhancement depends on the morphology of the nanocomposites. At high nanoclay content (> 3 wt%), a detrimental effect on the fracture toughness was observed. This is due to a weak nanomer/epoxy interfaces in a highly intercalated structure nanocomposite.
Simulation and Experimental Investigation on Water Meter Housing Using FV Method
Authors: Abidin Azrriq Bin Zainul , Manurung Yupiter Hp
Published: September 2013

This paper presents an investigation on hot forging process using simulation and experimental study. The product to be investigated was water meter housing made of material CuZn40Pb2. In the simulation part, Finite Volume Method (FVM) was applied by using commercial FEM/FVM software SIMUFACT version 10.0 and material database MATILDA. The simulation parameters followed the actual setting under consideration of the machine characteristic and friction. The simulation was further verified using crank-pressed forging machine with graphite lubrication. As the final result, the comparison defect of folds and laps between simulation and experiment is presented. It can be concluded that this simulation software offered fast solution analysis time in prediction of forging defects within good agreement between simulation and experiment.
Surface Reversal Method for Cylindrical Tool Characterization
Authors: Ismail Mohd Fauzi , Yanagi Kazuhisa , Isobe Hiromi
Published: September 2013

Cutting edges protrusion properties for cutting tools have significant effect of grinding surface finish and its characterization is crucial in understanding tool-work interaction. Existing definition of reference datum in surface topography analysis is not suitable for abrasive tool cutting edges protrusion characterization in relation to tool-work interaction. This paper proposed Surface Reversal Method for the reference datum determination in the characterization of cutting edge protrusion on flat end face of cylindrical cutting tool meant for vertical grinding. Fabricated cylindrical artefact is used to test the theory, accompanied with a specially made fixture. Performance of the proposed method is evaluated based on the repeatability of step height measurement on the topography component and inclination of the reference datum which extracted from primary surface measured by laser confocal scanning microscope. The proposed method provides better datum definition than conventional method for height measurement of the abrasive tool topography in relation to the tool-work interaction.
Analysis of Soot Particle Movement in Diesel Engine under the Influence of Drag Force
Authors: Mohd Hanafi Mohd Hafidzal , Wan Mohd Faizal W.M. , Roslizar A. , Zakaria Mohamad Shukri , Saadun Mohd Noor Asril , Saleman Abdul Rafeq
Published: September 2013

The formation of soot is influenced by the composition of air entrainment and structure of hydrocarbon in the fuel. Soot will then form during combustion in a diesel engine. Some of the soot particles will be released from the engine through the exhaust nozzle and some will stick to the cylinder walls. The soot that sticks to the cylinder wall can affect the lifetime of the lubricant oil. Subsequently this will decrease the durability of the diesel engine. By understanding the movement of the soot particles, the effect to the engine can be decreased. Therefore, the initial position and last position of soot particle was recognized through this study. The data for the formation of soot particles in the diesel engine was obtained from previous investigation. The study of soot movement at 8° crankshaft angle under the influence of drag force with different radial, axial and angular settings were carried out using a MATLAB routine. The results showed that the movement of soot particle will change with different parameter settings. Besides that, comparison of the results of soot particle movement influenced by drag force and without drag force has been carried out. It was observed that drag force caused shorter soot particle movement path and moves them away from the cylinder wall.
Optimize Vane Length to Improve In-Cylinder Air Characteristic of CI Engine Using Higher Viscous Fuel
Authors: Saad Idris , Bari Saiful
Published: September 2013

Environmental issues and the depletion of worldwide crude oil sources have developed the requirement for an alternative fuel to power internal combustion engines. Vegetable oil, waste cooking oil and biodiesel are all renewable, environmentally sustainable and compatible with current Compression Ignition (CI) engines with little to no engine modification necessary. These fuels however have a higher viscosity than conventional petro-diesel and may be referred to as Higher Viscous Fuels (HVF). HVF have reduced in-cylinder combustion efficiency when compared with petro-diesel which reduces the engine performance in terms of output power, torque and fuel efficiency. A possible solution to the reduced efficiency is through the use of a Guide Vane Swirl and Tumble Device (GVSTD). This device when installed in front of the air intake manifold may produce improved air flow characteristics. This improves the efficiency of the evaporation processes and air-fuel mixing and therefore improves overall combustion efficiency. The effect of GVSTDs on in-cylinder air flow was studied using 3D Internal Combustion (IC) engine simulation under motored engine conditions. This was done using ANSYS-CFX. The base model engine was adapted from the Hino W04D model CI engine. The model throughout all simulations was run at a constant speed of 1500 rpm. There are four parameters to consider for GVSTD models; vane length, vane height, vane angle and the number of vanes. For the purpose of this study, the vane height, vane angle and the number of vanes were maintained as constants leaving the vane length as the variable parameter. 11 GVSTD models were simulated each varying from 1.5 to 4.5 times the radius of the intake runner (R) in 0.3R increments. To analyze the air-flow characteristics, the maximum in-cylinder pressure, Turbulence Kinetic Energy (TKE) and velocity were measured. It was found that for the constant values for vane height, vane angle and the number of vanes of 0.2R, 35° twist angle and 4 perpendicularly-arranged respectively, the in-cylinder pressure, TKE and velocity were optimum for the vane lengths of 3.6 to 3.9 times R.
Contact Pressure Evaluation of a Gear Pair along the Line of Action Using Finite Element Analysis
Authors: Patil Santosh , Karuppanan Saravanan , Wahab Azmi Abdul
Published: September 2013

In loaded gears, contact behavior along the line of action changes tremendously. This leads to variation in gear contact conditions along the tooth flank, which may cause the failures such as surface wear, scuffing and pitting at different positions on the tooth surface. Hence, the information on the instant contact behavior along the line of action is crucial. However its evaluation for real gear conditions is very complicated. In this paper, the contact pressure for a pair of mating spur gears has been determined by Finite Element Analysis (FEA) using ANSYS software. The contact pressure results are then verified by twin-disc experimental results and the Hertzian contact pressure equation. The ANSYS results show the similar trend with the twin-disc test results, indicating that the FEA modelling is successful and provides good results.
Mechanical Properties of Trabecular Bone through Compression and Combined Compression-Torsion Test: A Comparative Study
Authors: Fatihhi S.J. , Ardiyansyah Syahrom , Harun Muhamad Noor , Kadir Mohammed Rafiq Abdul
Published: September 2013

In realistic service of life, trabecular bone is subjected to multiaxial stress histories during physiological routine activities thus investigation on the mechanical environment is important to evaluate the mechanistic aspects of bone failure in trauma. This study attempts to compare the material properties of trabecular bone with regard to mechanical properties in axial compression and combined compression-torsion. How superimposed axial compression and torsion loads would alter the axial mechanical properties is explained. Shear loading demonstrates tenfold reduction in modulus and 27% reduction in yield strength of bone in comparison to the properties of bone in pure compression. This condition shows that superimposed torsional loading is possible to accelerate bone yielding.
Experimental Investigation on the Energy Absorption Capability of Foam-Filled Nomex Honeycomb Structure
Authors: Wan Abdul Hamid Wan Luqman Hakim , Aminanda Yulfian , Dawood Mohamed Shaik
Published: September 2013

The effect of low density filler material comprising polyurethane foam on the axial crushing resistance of Nomex honeycomb under quasi-static compression conditions was analyzed. Honeycombs with two different densities, two different heights and similar cell size, along with five different densities of polyurethane foams were used in the research. A total of 14 unfilled Nomex honeycombs, 15 polyurethane foams, and 39 foam-filled Nomex honeycombs were subjected to quasi-static compression loading. The crushing load and capability of foam-filled Nomex honeycomb structure in absorbing the energy were found to increase significantly since the cell walls of honeycomb were strengthened by the foam filler; the walls did not buckle at the very beginning of compression loading. The failure mechanism of the foam-filled honeycomb was analyzed and compared with the unfilled honeycomb.
Potential Utilization of Biodiesel as Alternative Fuel for Compression Ignition Engine in Malaysia
Authors: Abdullah Nik Rosli , Ma’arof Muhammad Izzat Nor , Ahmad Ismail Nasiruddin , Kasolang Salmiah , Saad Nor Hayati
Published: September 2013

Global total petroleum deficit and environmental concern on the emissions issues concerning pure diesel had started a technological race in producing alternative sources of energy which includes renewable fuel. Among the developed renewable fuels is the biodiesel which is a type of fuel derived from various sources of vegetable plants and waste fuels. Various biodiesels have been engineered to beat par to or even perhaps, a leap better in term of performance topure diesel. In short,biodiesel has shown a promising sign as the best candidate in overcoming total dependent on petroleum-derived fuel.This paper gives review on various tests and experiments conducted on biodiesel in order to highlight the potentials preserved by the fuel and to further endorse for a more mass usage of biodiesel and simultaneously for Malaysia to be a potential global producer of biodiesel fuels in the near future.
All Metal Low Resistance Oxy Hydrogen Gas Generator and its Integration with VCR Engine
Authors: Sawant Suresh M. , Yadav Milind S.
Published: September 2013

Since its invention the oxy hydrogen gas has been used for many purposes like welding, lighting etc. In the recent past this gas has been experimented as a fuel additive in both SI as well as CI engines to improve the performance as well as emission parameters. Number of oxy hydrogen gas generators are designed and tested till today. This paper describes a new all metal low resistance oxy hydrogen gas generator which will be optimized in the later progress of the research work for maximum oxy hydrogen gas generation. In the later part of this paper a newly fabricated single cylinder twin spark variable compression ratio engine is discussed which will be further used for the testing of the oxy hydrogen gas from the optimized oxy hydrogen gas generator in blend with the hydrocarbon fuels at different compression ratios.
Effect of Preheated Fuel on Mixture Formation of Biodiesel Spray
Authors: Khalid Amir , Jaat Christian Yohan M. , Zaman Izzuddin , Manshoor B. , Ali M.F.M.
Published: September 2013

The key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and viscosity thus influences to the different spray atomization and fuel air mixing characteristics. Purpose of this study is to investigate the effect of preheated biodiesel on fuel properties, spray characteristics and mixture formation. The detail behavior of mixture formation was investigated using the direct photography system with a digital color camera. This method can capture spray evaporation, spray length and mixture formation clearly with real images. Increased preheated fuel is found to enhance the spray penetration, resulting in increased the spray area and enhanced fuel-air premixing.
Development of Low-Cost Wearable Servo Valve Using Buckled Tube Driven by Servo Motor
Authors: Nasir Abdul , Akagi Tetsuya , Dohta Shujiro , Ono Ayumu , Masago Yusuke
Published: September 2013

Recently, power assisted nursing care systems have received much attention and those researches have been done actively. In such a control system, an actuator and a control valve are mounted on the human body. Designing the system, the size and weight of the valve become serious concerns. The purpose of our study is to develop a small-sized, lightweight and low-cost servo valve for precise control using wearable pneumatic actuators. In this study, a low-cost wearable servo valve that can control the output flow rate by changing the twisted angle of the buckled tube in the servo valve is proposed and tested. The position control system of McKibben rubber artificial muscle using tested valve and embedded controller is also proposed and tested. As a result, we confirmed that the tested servo valve can control the flow rate in both supply and exhaust in an analog way. In addition, the estimated cost of the proposed valve can be reduced about 100 times cheaper (10 US Dollar) compared with the typical servo valve.
Comparative Study between Wheeled and Tracked Mobility System for Mobile Robot
Authors: Bakhsh Qadir , Hasnan Khalid , Ahmed Aftab
Published: September 2013

Robots are widely used nowadays in industries, commercial and domestic purpose for the completion of task in shortest time interval and accurate operation. In the design of a mobile robot, the main mechanical area on focus is the locomotion mechanism. The locomotion mechanism consideration would include the mobile robot flexibility, versatility and efficiency to complete the multi tasks in different environments, indoor and outdoor. This comparative study was focused on the mobile robot mobility systems between wheeled and tracked. This paper highlights the effects on mechanical design, velocity, energy and flexibility of each mobility system. A hybrid system was suggested depending on mechanical design, energy consumption and flexibility.
The Development of Finger Rehabilitation Device for Stroke Patients
Authors: Rahim Abdul Hakim Ab. , Bin Ab Patar Mohd Nor Azmi , Amin Adam Tan Mohd , Mahmud Jamaluddin
Published: September 2013

Most stroke patients who have lost the ability to use their fingers do not recover the functions of the fingers in their activity of daily living (ADL). This paper presents a novel approach in finger rehabilitation for acute paralysed stroke survivors. Based on repetitive exercise concept, the device is designed to provide support for fingers to do flexion and extension movements according to the patients range of motion. A conceptual design of the device is proposed after considering the current mechanism and control from similar current devices published and commercialised. A comparison between 4 existing main working mechanisms: (1) Pneumatic Cylinders, (2) Artificial Rubber Muscles, (3) Linkage Mechanism, (4) Cable-Driven Mechanism is also provided in this paper. The key for designing the device is home-based practice, easy to use and affordable. Further investigation and experiments on the proposed: Cable Actuated Finger Exoskeleton (CAFEx) are currently still in progress.
A SIS Epidemic Model with Eventual Impulsive Effects
Authors: de La Sen Manuel , Ibeas A. , Alonso-Quesada S.
Published: September 2013

This paper studies a time-varyingSIS(i.e.containing susceptible and infected populations) propagation disease model exhibiting a nonlinear incidence rate and impulsive eventual culling of both populations so that the individuals recover with no immunity to the disease. The nonlinear incidence rate consists of two time-varying additive terms proportional to the susceptible and infected populations normalized to the total population.
Control of Flexible Beam with Unmodelled Dynamics Using Second-Order Pole Placement and LQR Techniques
Authors: Rahman Z.A. , Mat Isa A.A. , Ali Haydar H. , Anuar M.A.
Published: September 2013

Control of a flexible beam such as that in flexible-link robot manipulators in many mechanical devices is very challenging, due in part to its intrinsic nature of unmodelled dynamics in a system. Such a system is said to be subjected to nonholonomic constraints, hence its feedback control is difficult to realize. This paper presents the application of control design based on second-order pole placement and LQR approaches to a single-link flexible robotic arm. In this case, a controller considering the flexibility of highly-flexible arm is employed to suppress the tip vibration of the manipulator. The effectiveness of the method is verified through computer simulations and consequently, the adequateness of the control performance and the feasibility of the system with a super-light link are shown.
Ambient Response Modal Analysis on a CEM-1 Single-Layer Printed Circuit Board
Authors: Anuar M. Azhan , Mat Isa A.A. , Zamri A.R. , Said M.F.M.
Published: September 2013

Since the level of vibration always depends on the natural frequencies of the system, it is important to know the modal parameters of such system to control failure and provide prevention actions. The demand for structurally reliable Printed Circuit Boards (PCB) has increased as more functions are required from electronic products along with less weight and smaller size. This imposes certain limitations and critical requirements. In this paper, investigation on the dynamic characteristics of CEM-1 Single-layer PCB using Operational Modal Analysis (OMA, or often called Output-Only or Ambient Modal analysis), is presented. The Frequency Domain Decomposition (FDD) and Enhanced Frequency Domain Decomposition (EFDD) techniques are applied on the PCB with free-free end condition. Comparison of results between both techniques and also with the result from Experimental Modal Analysis (EMA), will be shown. The understanding on dynamic behaviour of this structure provides valuable insight into the nature of the response and remarkable enhancement of its model, strength and vibration.
Experimental Study of Airless Spray Jet Breakup at Elevated Temperature and Pressure
Authors: Naz Muhammad Yasin , Sulaiman Shaharin Anwar , Ari-Wahjoedi Bambang
Published: September 2013

The presented research work was focused onto the understanding of the jet behavior of the sprays of heated water during the low pressure atomization process. This task was accomplished using an in-house built intermittently forced liquid spraying system capable of lowering the liquid viscosity and surface tension to a desired value and then atomizing it into a full cone spray patterns in the ambient air surrounding. Using a high speed camera, the jet breakup dynamics were visualized as a function of system input parameters. The analysis of the grabbed images confirmed the strong influence of these processing parameters on full cone spray characteristics. It was also predicted that heated liquids generate a dispersed spray pattern by utilizing the partial evaporation of the spraying medium that is the induction of thermal energy enhances the jet disintegration ability. The spray cone width and angle did not vary significantly whereas the Weber and Reynolds numbers along with other nozzle flow parameters showed an appreciable response to the load pressure and temperature at early stages of water injection. The ultimate objective of the work was to understand and control the airless spray jet breakup mechanism under reduced load pressure and high water temperature.
Impedance Induce Valve Pump in Closed Loop System
Authors: Mahat M. Mazwan , Sulaiman M. Arif , Ow Chee Sheng , Bahsan Rosnadiah , Ali N. Merlisa , Fizi C.S.
Published: September 2013

This paper summarises a study which aims to develop and analyze the performance of the valveless impedance pump. Mechanism of valveless impedance pump is to apply acoustic impedance mismatch in order to drive the flow and also consists of a flexible connection at the ends to the more rigid sections. Characteristics of liquid velocity and pressure at the pump base valveless impedance at various supply voltage and different frequencies have been discovered through experimentation. Secondly, this research also aims to discuss the effect volume flow rate (millitres / min) in the elastic tube impedance based on different parameters of the pump pinch. The variation of pinch location and pinch width are also available through the results of this study. This study begins with the design set up to use the software and followed by installing all equipment used for the experiments. Then, this study continues to get results and make an analysis of the impedance pump by experimentation. Results found that all the parameters used in this experiment affect the flow rate in the impedance pump. Additional experiments on the effect of the thickness of the flexible tube on the flow rate gave lower values when the flexible tube is relatively thicker.
Energy and Exergy Optimization of Hydrocarbon Recovery (HCR) Plant Considering Potential Environmental Impact and Economics
Authors: Tijani Alhassan Salami , Jaffar Ahmed , Kasolang Salmiah , Saad Nor Hayati
Published: September 2013

Process energy integration and continuous improvement of process technology are one of the increasing issues to ensure profitability of chemical productions. The energy conservation, process economics and environmental aspects are integrated at the early stage of the process development, the easier and less expensive to improve the process design. In this work different distillation process design alternatives have been considered with respect to evaluations of process economics and potential environmental impacts. The concept of exergy distribution has also been used as a tool to identify exergy loss profiles in each distillation unit. A multi-criteria decision making technique such as (Analytic Hierarchy Process) AHP is applied for ranking the alternatives. This method reveals that the heat pump distillation unit which has the highest score of 52 % is the best alternative when compare with the base case. In terms of the effluent streams, the base case has a less potential environmental impact (PEI) compared to heat pump. The lower total PEI/kg (7.45E-01) of the base case illustrates that the material utilization efficiency of the base case is better than that of the heat pump which PEI/kg is 8.14E-01.
Computational Simulation of Boil-Off Gas Formation inside Liquefied Natural Gas Tank Using Evaporation Model in ANSYS Fluent
Authors: Zakaria Mohamad Shukri , Osman Kahar , Saadun Mohd Noor Asril , Manaf Muhammad Zaidan Abdul , Mohd Hanafi Mohd Hafidzal
Published: September 2013

Research on the waste energy and emission has been quite intensive recently. The formation, venting and flared the Boil-off gas (BOG) considered as one of the contribution to the Greenhouse Gas (GHG) emission nowadays. The current model or method appearing in the literature is unable to analyze the real behavior of the vapor inside Liquefied Natural Gas (LNG) tank and unable to accurately estimate the amount of boil-off gas formation. In this paper, evaporation model is used to estimate LNG Boil-Off rate (BOR) inside LNG tank. Using User Define Function (UDF) hooked to the software ANSYS Fluent. The application enable drag law and alternative heat transfer coefficient to be included. Three dimensional membrane type LNG cargos are simulated with selected boundary condition located in the United States Gulf Coast based on average weather conditions. The result shows that the value of BOR agrees well with the previous study done with another model and with International Marine organization (IMO) standard which is less than 0.15% weight per day. The results also enable us to visualize the LNG evaporation behaviors inside LNG tanks.
Using Computational Fluid Dynamics Simulation to Perform Fire Investigation
Authors: Nasif Mohammad Shakir , Al-Waked Rafat
Published: September 2013

Fire occurred evening 10th July 1989 at Terwindle Rest Home Auckland. Incident report shows that this fire resulted in seven fatalities and extensive fire damage to the building. The primary cause of the death was carbon monoxide poising from smoke inhalation. The fire started at the lounge which contained ten upholstered couches with polyurethane foam padding. Sprinkler fire protection system was not installed and the building has no smoke detection system (based on the New Zealand Building code requirement that was imposed at that time). In this study, the fire is modeled using Computational Fluid Dynamics (CFD) software FDS (Fire Dynamic Simulator). The heat release rate of the fuel burned was obtained from lab measurement of a sofa. The results were validated against the approximate time scale of the progress of the fire as it was found from the fire investigation report. It has been found that FDS can provide accurate simulation to the fire which can be used to perform fire investigation provided that the correct heat release rate of the fire used in the model.
Numerical Analysis on the Effects of Cavity Geometry with Heat towards Contaminant Removal
Authors: Saadun Mohd Noor Asril , Azwadi C.S. Nor , Hazwani M.N. , Zakaria Mohamad Shukri , Manaf Muhammad Zaidan Abdul , Mohd Hanafi Mohd Hafidzal
Published: September 2013

Contaminants are recently discovered at the joint of large piping system and causing defect to industrial product. A computational analysis can be used as a solution of the hydrodynamic contaminant removal without any modification needed. In this paper, the effect of heat is introduced to analyze the heat transfer and flow field in a channel with cavity heated at the bottom sides coupled with different shape of cavity. The cavity shape used comes with three shapes i.e. square, triangle and semicircle. The process of fluid dynamic in a cavity is modeled via numerical solution of the NavierStokes equations using Cubic Interpolated Profile (CIP) method. By using the simulation of hydrodynamic contaminant removal, the flow of streamlines and vortices pattern was investigated in the cavities. In order to remove all of the contaminant, hydrodynamic need to take part in this simulation which is flow from the inlet of the channel and create vortices to remove it from the cavities. The result shows that the percentage of contaminant removal is higher for semicircle cavity with higher Grashof number. The result also indicates that vortices formation is highly dependent on the cavity geometry and creates a buoyancy effect.
Application of Fuzzy Logic Approach to Predict Maximum Oil-Film Pressure in Journal Bearing
Authors: Ahmed Diyar I. , Kasolang Salmiah , Khidhir Basim A. , Mat Taib C.F.
Published: September 2013

In the present work, a fuzzy logic model is developed to predict the oil-film pressure in hydrodynamic plain journal bearing. In the development of predictive model, journal bearing parameters of speed, load and oil-feed pressure are considered as model independent variables. For this purpose, a number of experiments, based Box-Behnken experiment design technique, are performed to observe the oil-film pressure values. The results revealed that the model is able to predict the oil-film pressure adequately.
The Effects of Oil Groove Position on Torque and Frictional Force in Hydrodynamic Journal Bearing
Authors: Ahmad Mohamad Ali , Kasolang Salmiah , Dwyer-Joyce Rob , Bakar Mimi Azlina Abu
Published: September 2013

Axial groove is a common supply method of distributing lubricant within a journal bearing. Lubricant is generally fed at a specific supply pressure to ensure that the journal and the bearing surface are separated. Shearing action between lubricant and bearing parts creates frictions which contribute to power loss in journal bearing. In the present study, an experimental work was conducted to determine the effect of oil groove location on torque and frictional force in hydrodynamic journal bearing. A journal diameter of 100mm with a 12 length-to-diameter ratio was used. The oil supply pressure was set at 0.20 to 0.25 MPa. The groove was positioned at 3 different locations namely 00, +150and +300. Measurements of torque and frictional force were obtained for speed values of 300, 500 and 800 RPM at different radial loads. It was observed that the change in oil groove location has affected the fluid frictional force and friction coefficient to some extent.
Wear Particle Characterization and Severity Evaluation of Perodua Myvi 1.3L Automatic Transmission (AT) Fluid
Authors: Latip Syazuan Abdul , Kasolang Salmiah , Alias Siti Khadijah , Abd Rashid Amirul , Abdullah Abdul Hakim , Yunus Syarifah
Published: September 2013

s. This paper investigates the characteristic and severity level of both wear and wear particles occurred in Perodua MyVi 1300cc automatic transmission (AT) mechanism via wear particle analysis approach. The analyses deployed were based on ferrographic and surface roughness analysis. The work of analysis strictly conducted on automatic transmission fluid (ATF) Perodua original equipment manufacturer (OEM) (ATF-3) series via continuous endurance dynamometer basis at the operating speed of 3000rpm. The operating mileage tested ranged from 0km up to 10,000km maximum operating distance. The wear particle generated at each operating mileage of 1,500km, 3,000km, 4,500km, 7,000km and 10,000km was accordingly analyzed morphologically and qualitatively. Ferrographic analysis is by principal has been recognized as one of the most reliable analysis incorporated with wear particle analysis (WPA) concern [1]. In concern of this study, it is applied to examine the morphology, mode and characteristic of wear particles generated. The surface roughness analysis meanwhile conducted to qualitatively evaluate and predict the wear condition of components within the AT mechanism via qualitative surface texture analysis of the wear particles. The outcome from the investigation done on the wear particles surface characteristics could interpret the wear behaviour and progress (stage/phase) as the surface characteristics of the wear particles do depict the surface characteristics of the wear components [2, 3].
The Study of the Vibration Characteristics of the Cantilever Beam with a Surface Crack
Authors: Chen Li Hua , Duan Jian Wei , Sun Yue , Li Jing
Published: September 2013

In this paper, the physical model of the cantilever beam with a surface crack is established to study the free vibration of the cracked beam from three aspects that are theoretical analysis, FEM analysis, and experiment. At the same time, the relation between the crack parameter and the vibration characteristics, which are natural frequencies and the modes of each order, is obtained through analysis. The theoretical analysis is on the basis of the mode analysis theory and applied mechanics. The crack is regarded as a flexible hinge. Utilizing the external boundary conditions and internal boundary conditions at the crack, the free vibration characteristics are obtained combining with the vibration mechanics. With the ANSYS software, a finite element model of the cracked beam is established by the beam element. During the process of calculation, it calculates the natural frequencies and the modes of cracked beam with different parameters of crack. The results obtained from the experiment are in agreement with the results obtained from the theoretical and the FEM analysis. So the accuracy of the theoretical analysis and the numerical simulation is verified by the experiment. At last, the effects of the crack location and depth on the natural frequencies and modes of each order are shown, and it could provide the theoretical, numerical and experimental basis for the identification of cracked materials and the relevant study.
Large Eddy Simulation of Flow Past Circular Cylinder Based on the Least Square Meshless Method
Authors: Wang Yuan Ding , Tan Jun Jie , Cai Xiao Wei , Ren Deng Feng
Published: September 2013

Large Eddy Simulation (LES) based on the least square meshless method was proposed in the present paper to simulate the classical turbulent flow around a stationary 2D circular cylinder. The subgrid scale model of Smagorinsky-Lily was employed to close the Navier-Stokes equations filtered by Favre filter. The Reynolds number is 3900 which means that the flow is subcritical and the wake is fully turbulent but the cylinder boundary is still laminar. Results obtained in this paper were evaluated by comparison with published experimental results and other numerical results. The results obtained in the present work show better agreement with the experimental values than other two-dimensional LES results .
Application of a Tensioner on a Chain Drives Multibody Model
Authors: Pereira Candida , Ambrósio Jorge , Ramalho Amilcar
Published: September 2013

The dynamics of chain drives is a complex issue due to the polygonal effect and the multiple successive impacts that take place. The combined effect of these phenomena leads to discontinuities in the systems velocities giving rise to transversal and longitudinal vibrations on the chain spans. To investigate the pretension effect on the drive dynamics, a tensioner is applied to a generalized chain drives multibody model developed and implemented in a computational code by the authors. In this model, the clearance revolute joints formulation is used to handle the dry contact between all drive components. The pretension changes the characteristics of the contact pairs by enforcing a continuous contact with only a small number of contact losses. When no pretension is used, the contact is characterized by a sequence of short duration contacts. The strands of the pretensioned chain vibrate with higher frequency but smaller amplitude in comparison to the non-pretensioned system.
Dimensionless Correlating-Equations for Predicting the Optimal Tilting Angle of Water-Filled Square and Shallow Enclosures Differentially Heated at Sides
Authors: Cianfrini Marta , de Lieto Vollaro Roberto , Quintino Alessandro , Corcione Massimo
Published: September 2013

Laminar natural convection heat transfer inside water-filled, tilted square and shallow cavities heated at one side and cooled at the opposite side, is studied numerically. A computational code based on the SIMPLE-C algorithm is used to solve the system of the mass, momentum and energy transfer governing equations. Simulations are performed using the Rayleigh number based on the length of the heated and cooled sides, the height-to-width aspect ratio of the enclosure, and the positive tilting angle with respect to the gravity vector (which corresponds to configurations with the heated wall facing upwards), as independent variables. It is found that the heat transfer performance has a peak at an optimal tilting angle which increases as the Rayleigh number is decreased and the aspect ratio is increased. On the basis of the results obtained, a set of dimensionless correlations is developed.
The Characteristics of Fluid Flow and Heat Transfer in Wavy, Dimple and Wavy-Dimple Microchannels
Authors: Gong Liang , Wei Bo
Published: September 2013

The flow and heat transfer characteristics were numerically studied in wave, dimple and wave-dimple microchannels for thermal managements on the chip of Intel i7-996X with heat flux of 0.56 W/mm2.The results show that, in microchannles heat sink, the dimple structure could reduce the flow resistances and the wavy wall could enhance heat transfer. According to the both advantages, two types of microchannel heat sink both with dimples and wavy walls were designed, and the flow and heat transfer characteristics were numerically studied. It is proved that the wave-dimple microchannels heat sink holds the characteristics of enhancing heat transfer with low pressure drop, which implies it has great potential of development and application prospect.
Dynamic Response of Magnesium Alloy and its Nanocomposite under High Strain Rate Compressive Loading
Authors: Jing Xiao , Dong Wei Shu
Published: September 2013

Magnesium alloys due to their low density, high strength to weight ratio and good impact resistance have been increasingly used in automotive, aerospace and electronics industries. However, the poor ductility and low strength of magnesium alloys limit their usage in impact situations. The dynamic properties are critical to evaluate the materials response in impact situations. In this study, magnesium alloy AZ31B and its composite containing 1.0vol% SiC nanoparticles were subjected to quasi-static and dynamic compressive loading to investigate the influence of strain rate and the presence of nanoparticles on the mechanical behavior. The dynamic compressive behaviors of both materials have been examined over a wide range of strain rate between 700 s-1and 2800 s-1. Compared to quasi-static loading, both materials exhibit significantly higher yield stresses and compressive strength, much better ductility, and thus a higher energy absorption capacity under dynamic compression. Under dynamic loading, the flow stress of both materials first increases with increasing strain rate from 700 s-1to 2300 s-1but then it decreases when the strain rate is above 2300 s-1. In terms of nanoparticle addition, its influence on the enhancement of yield stress and ultimate compressive strength are notable while the ductility remains the same resulting in better energy absorption performance of nanocomposite. This indicates that the nanocomposite has potential to replace the existing magnesium alloys for various applications where impact/shock loads are encountered.
Influence of Magnetic Field on Chip Serration Frequency for Turning Stainless Steel AISI 304
Authors: Mohamad Ummu Atiqah Khairiyah Bt. , Nurul Amin A.K.M. , Arif Muammer D. , Bin Abdul Muthalif Asan Gani
Published: September 2013

In this research, respond surface methodology (RSM) model was developed for the investigation and prediction in order to study the effect of cutting parameters and chip serration frequency during machining stainless steel AISI 304. The model can be used for analysis and prediction for complex relationship between cutting parameters and chip serration frequency on metal cutting process. Tin coated carbide insert is used with 120mm tool overhang to investigate the process. Permanent magnet with the 4500 Gauss power is compared in this experiment with the natural frequency to obtain the required data during machining. Chatter is found to appear as a resonance phenomenon when the frequency of chip serration is equal to or integer multiple of the prominent natural frequency/frequencies of the system component (s). Hence, it is important to study the chip serration frequency. At lower cutting speeds the chip is often discontinuous, while it becomes serrated as the cutting speed is increased. It has been identified that the chip formation process at higher speeds also has a discrete nature, associated with the periodic shearing process of the chip. In this paper a statistical technique is proposed to predict the frequency of chip serration as a function of cutting parameters in turning of stainless steel AISI 304 using Response Surface Methodology (RSM). 95% confident level was predicted using analysis of variance (ANOVA).
Process Management of Aircraft Manufacturing Based on Single Enterprise BOM
Authors: Li Zhou Yang , Lei Yan Ni
Published: September 2013

nformation exchange and sharing are difficult in manufacturing process for manufacturing enterprises, especially for aircraft manufacturing enterprises, which have complex product to fabricate and mass information to handle. To solve this problem, a Single Enterprise BOM (SEBOM) based Aircraft Manufacturing Process Management System (AMPMS) is promoted to support the whole process of aircraft manufacturing, based on the analysis of aircraft manufacturing process and the process of data flowing. In AMPMS, in order to satisfy the information requirement, a SEBOM is established by unifying various BOM data. A unified SEBOM management platform is established to managing distributed and heterogeneous SEBOM data. Furthermore, the key technologies including BOM data mapping and BOM data agent management are discussed in detail. The validity and feasibility of AMPMS system are verified by developing a prototype system.