22 research outputs found

    Solution to navier-stokes equation in stretched coordinate system

    Get PDF
    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

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

    Get PDF
    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

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

    Get PDF
    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

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

    Get PDF
    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

    Characteristic Of Thermoplastics Corn Starch Composite Reinforced Short Pineapple Leaf Fibre By Using Laminates Method

    Get PDF
    In recent years, the increased demand of biodegradable polymers has sparked the research interest in the development of alternatives to conventional polymers. As such, starch considerably one of the best substitutes to the non-degradable polymers owing to its advantages. The main purpose of this study is to investigate the mechanical, physical and environmental characterization of bio-composites, which is in this case the thermoplastic corn starch (TPCS) reinforced with a 2 mm length of pineapple leaf fibre(PALF). The selection of different weight percentages in the range of 20 to 60 weight percentage (wt.%) of PALF contents were applied in this work. The mixtures of TPCS with different wt.% of PALF were made by using a hot compression moulding at 165 °C for 15 minutes. Several testing has been performed to determine the bio-composites characteristics. The results show that by incorporating 40 wt.% loading of PALF, the tensile and modulus strength has increased to the maximum. It is also seen that there is an inverse relationship between the moisture content and the wt.% loading of PALF. However, the water and moisture absorption show a direct relationship with wt.% loading of PALF. Meanwhile, the soil burial decreases when the wt.% loadings of PALF increase while the results for water solubility suggest vice versa. It is also found that the TPCS with 40 wt.% of PALF have a good miscibility between matrix/fibre in the bio-composites

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

    Full text link
    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

    Get PDF
    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

    Get PDF
    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.Â

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

    Get PDF
    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

    Three dimensional integrated software development for air-particle flow simulation through image-based upper human airways

    Get PDF
    The effort to reconstruct and simulate flow-particle behavior in realistic patientspecific airway system requires multi-software skills. Conventionally, pre-processing, simulation and optimization and post-processing stages are carried out explicitly via a combination of commercial, open source and/or in-house engineering software. The tedious procedure had left more significant medical analysis such as flow pattern classification, patient group-based flow analysis and statistical flow studies at bay. In this work, the focus is on the development of a dedicated software that is capable of performing all the three stages for any patient-specific data set. A novel approach of combining the efficient Immersed Boundary method and Finite Difference Splitting solver within a matrix-based open source programming platform has radically simplified the procedure especially in the pre-processing stage. The air and particle interactions are based on Eulerian-Lagrangian technique with comprehensive validations for each stage of the solvers integration. A non-dimensional convergence error of less than 1 x 10-6 was consistently set for all the validations. An air flow rate of 30 litre / minute was used throughout the analyses representing the normal inhalation condition while a number of 10,000 and 5,000 micro particles were modeled for simplified and image-based airways respectively. The assessment analysis showed that 42.35% of the particles inhaled by female subject managed to reach the end of trachea while male subject with epiglottis blockage recorded only 0.43%. None of the inhaled particles managed to pass through the trachea of the oversized male subject. This work suggests that such pattern analyses are crucial to facilitate medical practitioners in their patient-specific diagnosis and decision making process of airway flow related diseases
    corecore