30 research outputs found

    Solution to navier-stokes equation in stretched coordinate system

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    Solution to Navier-Stokes equation by Splitting method in physical orthogonal algebraic curvilinear coordinate system, also termed 'stretched coordinate' is presented. The unsteady Navier-Stokes equations with constant density are solved numerically. The linear terms are solved by Crank-Nicholson method while the non-linear term is solved by the second order Adams-Bashforth method. The results show improved in comparison of efficiency and accuracy with benchmark steady solution of driven cavity by Ghia et al. and other first order differencing schemes including splitting scheme in Cartesian coordinate system. Enormous improvements from the original Splitting method in Cartesian coordinate observed where accurate solutions are obtained in minimum 17 X 17 from 33 X 33 resolution for Re = 100, 47 X 47 from 129 X 129 resolution for Re = 400 and 65 X 65 from 259 X 259 resolution for Re = 1000

    Non-dimensional distribution pattern analysis of particle transportation in simplified pipeline system

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    Sustainable preservation of pipeline system that deal with particle transportation is more appealing these days. In petroleum industries for instance, sand transported through the pipelines pose serious problems ranging from blockage, corrosion, abrasion and reduction in pipe efficiency to loss of pipe integrity. Accurate four-dimensional simulation that caters the transient effect of the phenomena is used to promote sustainability in design, evaluation and maintenance procedures. This is employed to minimize conventional practices which are costly and inefficient. This work demonstrates the advantages of applying four-dimensional Splitting Fluid-Particle Solver to simulate particle transportation within a simplified pipeline system. Single-phase fluid with solid sphere particles are the assumptions while drift and gravitational forces are taken into account. Effect of fluid flow rate and particle weight alterations are observed within vertical curled and 2-1-2 segmental pipeline. Flow rate variation on multiple inputs shows that proper simulation is essential in order to predict fluid flow behavior prior to pipeline construction. Particle weight variation shows that simulation can lead to better prediction of potential areas of blockage, corrosion, abrasion and other piping system issues. This work proves that four-dimensional simulation can promote sustainability, cost effectiveness and efficiency of pipeline system management

    Comparison of 2D and 3D modelling applied to single phase flow of nanofluid through corrugated channels

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    Nanofluid flow through non-corrugated and corrugated channels is studied using a two-dimensional (2D) and three dimensions (3D) numerical simplification. Due to the high computational costs of a full 3D grid model, the 2D approach offer a more practical advantage. However, little information about its validity is available. The aim of this study is to explore to which extent 2D simulations can describe the flow within a 3D geometry, and to investigate how effective the commonly used 2D numerical simplification is in nanofluid flow through non-corrugated and corrugated channels. A case study has implemented with 2D and 3D mesh models to compare their results taking into consideration the analysis of heat transfer and pressure drop. A simulation has been carried out using Ansys fluent software to compare the results for different Reynolds Numbers ranges from 10000 to 30000 and different geometries non�corrugated, semicircle and rectangular channels. The results show that for non�corrugated channel there is a slight difference between 2D and 3D results for all Reynolds number ranges, while for both semicircle and rectangular corrugated channels, the difference becomes larger for high Reynold’s Number

    A review on the selection of granular fertiliser distribution methods for Malaysia’s paddy field on a large scale.

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    High efficiency distribution applicators, such as boom sprayer (air blower concept), Kuhn Axis fertiliser spreaders (rotating disc concept), and pendulum spreader (magnetic concept) were the response to the call to distribute granular fertiliser to a paddy field on a large scale. Each of these distribution applicators had their own characteristics which are optimised for different purposes. This paper shows the review results after studying journal papers to select the most suitable applicators for Malaysia’s paddy field on a large scale. The analyses included the compliments of these applicators toward the type of granular fertiliser used in Malaysia’s paddy field, the maintenance cost of these applicators, the suitability of machine to be used in the landscape of Malaysia’s paddy, the distribution areas covered by these applicators, and the accuracy of distribution. The review concluded that Kuhn Axis fertiliser spreader was found to be the most suitable applicator compared to other applicators

    Finite element modelling of fixed-fixed end plate attached with vibration absorber

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    The present paper investigated the effect of the lightweight dynamic vibration absorber (LDVA) to reduce vibration of thin walled structure. The free and forced vibration response of a rectangular thin plate were performed using finite element method. Subsequently, the effects of attached single and dual LDVA were analysed in depth by using Ansys workbench 14.5. Results demonstrated that single LDVA attached at the centre of the plate succesfully attenuate vibration over the frequency range of 0- 600 Hz. By contrast, attached with dual LDVA only suppresses the resonance of the first second and fourth modes but not for third and fifth modes of thin walled structure. It was found that by simply increasing the weight of mass does not improve the vibration absorption over the entire frequency range. The study conclude that attached single LDVA are better than dual LDVA for vibration absorption of thin walled structure over the entire frequency range

    Mechanical properties of caco3 extracted from cockle shell with high density polyethylene (HDPE) for biomaterials in bone substitute application

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    This study was conducted to produce CaCO3 powder extracted from cockle shells as bioceramic materials which later combined with high density polyethylene (HDPE) as the polymer to produce composite as the final product. For CaCO3 clarification, the powder form of bioceramics was analyzed using FTIR, SEM and EDX analyses. Then, the composites produced were tested for mechanical properties via tensile and hardness tests. Firstly, the wasted cockle shells were all washed to remove dirts and soaked in regular water overnight before left to dry at room temperature. Then, they were all ground up between range 100 – 200 µm several times until the required size were obtained. The spectrum for FTIR showed identical result as previous work at reading 857.22cm-1 which represent vibrational bonds that can be attributed to the characteristics of external plane bending vibration of carbonate. After the confirmation, it was added to the melted HDPE to produce stronger composite via injection moulding method. Injection moulding process was to produce the sample into the shape of dumbbell to perform mechanical tests, tensile and hardness test with three parameters for each weight ratio. It could be concluded that pressure, velocity and temperature affecting the hardness of samples. In this research, the greatest value of Young’s modulus and maximum force which are 852.2 MPa and 271.457 kN, respectively. In conclusion, cockle shell could become great biomaterial as it provide good in mechanical properties. Furthermore, the source also abundantly available and with the fully usage of this waste to something more useful, it is able to reduce contamination to the earth. Then, the combination with any polymer is able to produce strong composite that could apply in any field. For this research, the composite is focus in biomaterial usage, especially in orthopaedic field for bone implant. For instance, CaCO3 are proved to be function at higher temperature, and further future works might be required to search the maximum temperature that this material could achieve

    Performance of Dual Depth Camera Motion Capture System for Athletes’ Biomechanics Analysis

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    Motion capture system has recently being brought to light and drawn much attention in many fields of research, especially in biomechanics. Marker-based motion capture systems have been used as the main tool in capturing motion for years. Marker-based motion capture systems are very pricey, lab-based and beyond reach of many researchers, hence it cannot be applied to ubiquitous applications. The game however has changed with the introduction of depth camera technology, a markerless yet affordable motion capture system. By means of this system, motion capture has been promoted as more portable application and does not require substantial time in setting up the system. Limitation in terms of nodal coverage of single depth camera has widely accepted but the performance of dual depth camera system is still doubtful since it is expected to improve the coverage issue but at the same time has bigger issues on data merging and accuracy. This work appraises the accuracy performance of dual depth camera motion capture system specifically for athletes’ running biomechanics analysis. Kinect sensors were selected to capture motions of an athlete simultaneously in three-dimension, and fused the recorded data into an analysable data. Running was chosen as the biomechanics motion and interpreted in the form of angle-time, angleangle and continuous relative phase plot. The linear and angular kinematics were analysed and represented graphically. Quantitative interpretations of the result allowed the deep insight of the movement and joint coordination of the athlete. The result showed that the root-mean-square error of the Kinect sensor measurement to exact measurement data and rigid transformation were 0.0045 and 0.0077291 respectively. The velocity and acceleration of the subject were determined to be 3.3479 ms-1 and –4.1444 ms-2. The result showed that the dual Kinect camera motion capture system was feasible to perform athletes' biomechanics analysis

    Forecasting modelling of cockles in Malaysia by using time series analysis

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    Cockle farmed in Malaysia are from Anadara genes and Arcidae family which known as blood cockle. Normally, it was found in the farmed around mangrove estuary areas in the muddy and sandy shores. This study aims to predict the production of cockle to ensure sure the cockle supplies are synchronised with the demand. Then, based on the demand, the prediction result could be used to make decision either to import or export the cockle. The data were taken from the Department of Fisheries Malaysia (DFM) and it has cyclic pattern data. There are two methods used in this study which are Holt-Linear method and Auto regressive moving average (ARMA). In determining the best fitted model between the two methods, the mean square error (MSE) values will be compared and the lowest value of MSE will assign as the best model. Result shows that ARMA(1,1) is the best model compared to Holt-Linear. Therefore, ARMA(1,1) model will be used to forecast the production of cockle in Malaysia

    Analysis of Musculoskeletal Disorder Due To Working Postures via Dual Camera Motion Capture System

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    Ergonomic are known as the study of work. It helps the worker to fit with the environment of the workplace for example the tools, equipments and the work station. Poor ergonomic practice can affect the performance of the worker and the quality of the product besides can cause loss to the company. This study have three main purpose which is to establish the optimal set up of the dynamic RULA analysis in UTHM, to compare the performance of static RULA analysis with the current dynamic RULA analysis and to identify the effect of current working posture to the musculoskeletal disorder of the university. The ergonomic tools that are use in this study are Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) and Rapid upper limb assessment (RULA). Besides that, motion captures system and Kinect camera is use for 3D dynamic RULA analysis. Besides that, 2D static analysis and 3D dynamic analysis must run the experiment and record the video of the subject motion simultaneously to ensure the similarity in terms of result obtain. Thus, this research finds that the 3D dynamic analysis is more accurate compare with the 2D static analysis. This can be proved by comparing the length of the joint point of 2D static analysis and 3D dynamic analysis with the actual length. 3D dynamic method provided 3 axes while the other method only provided 2 axes. Besides that, 3D dynamic method are analyze by the program while 2D static method are analyze manually by the user that not entirely accurate. The result for comparing the performance of the 2D static analysis and 3D dynamic analysis shows that the respondent 1 and 2 have high risk to get neck pain based on the 3D dynamic analysis RULA score. CMDQ analysis shows that the body part of respondent 1 and 2 that are most probably affected by the MSD is leg.Ă‚

    Development of Distraction Risk Index (DRI) Among the Intrastate Bus Driver in Kuala Lumpur, Malaysia

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    Bus services is one of the main public transport chosen by the people all around the world especially in the big city such as Kuala Lumpur. However, the safety of the passenger of the bus services become main concern among the researchers due to increasing number of accidents among the bus services. Some researcher found that, the major factor of the accidents involving bus services was caused by the bus driver distraction. Therefore, the objective of this research is to develop the Distraction Risk Index (DRI) among the intrastate bus driver. This research will only focus on the intrastate bus driver in Kuala Lumpur. Survey which adapting the Hampton University Transportation Centre Bus Driver Distraction Survey was used and distributed to 215 intrastate bus drivers in Kuala Lumpur, Malaysia. It was found that there were four sources of distraction which classified as very high risk which were condition of the bus, traffic congestion, drivers’ welfare and drivers’ health. Findings of this research can be used as a platform for future improvement for the performance of the intrastate bus services. This research also can provide assistance to future researchers to design and provide solution to overcome sources of distraction
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