Now showing 1 - 9 of 9
  • Publication
    Influence of material properties on the fluid-structure interaction aspects during molded underfill process
    ( 2017)
    C.Y. Khor
    ;
    ;
    M.U. Rosli
    ;
    ;
    M.S Zakaria
    ;
    A.F.M. Yamin
    ;
    M.S. Abdul Aziz
    ;
    M.Z. Abdullah
    This paper presents the investigation of the effects of epoxy moulding compound’ (EMC) viscosity on the FSI aspects during moulded underfill process (MUF). Finite volume (FV) code and finite element (FE) code were connected online through the Mesh-based Parallel Code Coupling Interface (MpCCI) method for fluid and structural analysis. The EMC flow behaviour was modelled by Castro-Macosko model, which was written in C language and incorporated into the FV analysis. Real-time predictions on the flow front, chip deformation and stress concentration were solved by FV- and FE-solver. Increase in EMC viscosity raises the deformation and stress imposed on IC and solder bump, which may induce unintended features on the IC structure. The current simulation is expected to provide the better understandings and clear visualization of FSI in the moulded underfill process.
      2  14
  • Publication
    The effect of silica toward polymer membrane for water separation process
    The aim of this present work was to investigate the effect of different percentage rice husk silica (RHS) particles composition towards polymer mixed matrix membrane microstructure and performance in water separation process. The polymer membranes were prepared by a phase inversion method using polysulfone (PSf), N-methyl-2-pyrrolidone (NMP) as solvent, distilled water as non-solvent and fixed RHS at 400°C as an additive. The microstructures of PSf/PEG/RHS sample were characterized by performing scanning electron microscope (SEM). The performance was measured by using pure water flux and humic acid for the rejection test. The analyzed result of SEM analysis revealed that the addition of RHS obviously improved the microstructure of the membrane especially at the top and sub layer at the range of 1 until 3 wt. %. This was proven by the pure water flux (PWF) value measured from 114.47 LMH to 154.04 LMH and rejection from value 83% to 96% at this specified range substantially higher than the mixed matrix membrane with synthetic silica. In fact, the presence of RHS particles not only improved the properties and performance of membrane but also possess biodegradable properties which can minimize the pollution and provide a membrane green technology system.
      32  1
  • Publication
    Effect of twist blade distributor on velocity distribution in a swirling fluidized bed
    Swirling Fluidized Bed (SFB) is one of the liquid-solid interaction in fluidization improved from conventional systems. This system is usually viewable in the power generation, chemical industry, material production and drying processes. Inside the SFB, there is annular blade distributor which will cause the air to pass through and create a swirl motion on the bed. The energy consumption of a fluidized bed system depends on the distributor’s design. The current study has purpose a new design that applies to existing designs of blade inclination angle. The simulation study was conducted using Computational Fluid Dynamics (CFD) to obtain the result of velocity distribution and pressure drops on various blade distributor designs. This study uses two (2) twist angle (80° and 100°) via number of blade distributor (40, 50 and 60). In this study, tangential velocity is the main velocity component by reason of the velocity represents the rotating air velocity in fluidization system. Overall, the design of the 100° twist angle and 40 blades distributor are the best distributors of blades compared to others.
      4  24
  • Publication
    Biomechanical assessment of different surgical approaches of zygomatic implant placement on prosthesis stress
    The treatment of severely atrophic posterior maxillae without bone augmentation by using zygomatic implants has received a major attention in prosthodontics due to great implant survival rates. However, mechanical implant system failures were still reported irrespective of surgical techniques used for zygomatic implant placement. Two main prominent approaches, the intrasinus and extramaxillary possess their own advantages and drawbacks with no particular indication found, to date, to highlight the best technique in relation to prosthesis stress. Thus, this study emphasised on the computational evaluation of both approaches with regards to the prosthesis responses. Two sets of finite element models comprising bones, soft tissue, implants, abutments, and prosthesis were prepared accordingly. The models were then assigned with the material properties, contact modelling, and loadings as closely as possible with the real conditions. The results showed that the extramaxillary technique reported a more promising maximum stress value and distribution within the prosthesis than the intrasinus. Moreover, the prostheses in both approaches seemed to have a low tendency to failure as the stress levels were significantly less than the stress limit of the material.
      4  37
  • Publication
    Effect of heat sink design on the thermal characteristic in computational fluid dynamics analysis
    The thermal management in the electronic device or system using the heat sink is important to ensure the device or system operating under the allowable temperature. The present study aims to investigate the thermal characteristic (i.e., temperature distribution) of the various heat sink designs via computational fluid dynamics (CFD) analysis. The electronic cooling process of the heat sink is carried out via CFD software. The temperature distribution of the various heat sink designs (i.e., plate fin, circular pin fin and rectangular fin) was analyzed and compared. The CFD analysis revealed the plate fin heat sink has lowest temperature distribution on the fin region. High temperature distribution was observed on the pin fin heat sink. The non-uniform temperature distribution was attributed by the direction of inlet airflow, whereas the low temperature was found in the region that close to the inlet airflow. Thus, the research findings indicated the design of heat sink significantly affects the temperature distribution during the electronic cooling process.
      3  26
  • Publication
    Effect of zinc addition on the performance of aluminium alloy sacrificial anode for marine application
    In this work, the effect of zinc addition on the performance of aluminum-based sacrificial anode in seawater was investigated. The parameters used in assessing the performance of the cast anodes are anodic efficiency, protection efficiency and polarized potential. The content of zinc in the anodes was varied after die casting. The alloys produced were tested as sacrificial anode for the protection of mild steel for marine application at room temperature. Factors such as reactivity of zinc particles in the seawater, corrosion activity during the period of experiment, pH of seawater and the electronegativity potential of zinc were collected for analysis. Overall findings shows addition of zinc increases rate of corrosion to the sacrificial anode and the protection offered by the sacrificial anodes measured and collected in PIT shows the seawater react to sacrificial anode and no porosity reaction between the anodes. The microstructure showed the intermetallic structures of β-phase which breakdown the alumina passive film, thus enhancing the anode efficiency.
      46  2
  • Publication
    Conceptual design and computational analysis of traditional boat passenger seat
    ( 2020-11-02)
    Hasbullah M.H.
    ;
    ;
    Nurul Anasuhah Zakaria
    ;
    ; ; ;
    Norfaseha Nordin
    ;
    Deraman A.S.
    Todays, there are various of optimisation methods that have been studied by many researchers in order to find the appropriate combination of processing parameters setting in the injection moulding process. From the previous literatures, the optimisation works have been proven will improve the moulded part quality. In this study, the application of optimisation work to improve warpage of front panel housing has been explored. By selecting cooling time, coolant temperature, packing pressure and melt temperature as the variable parameters, design of experiment (DOE) have been constructed by using the rotatable central composite design (CCD) approach. Response Surface Methodology (RSM) was performed in order to define the optimal processing parameters setting which will optimise the warpage condition. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 47.1% after optimisation. The findings show that the application of optimisation work offers the best quality of moulded part produced.
      3  30
  • Publication
    Computational Fluid Dynamics (CFD) Simulation on Mixing in T-Shaped Micromixer
    Computational Fluid Dynamics (CFD) simulation used to analyse the fluid mixing in micromixer. There are two cases of miscible liquids that involved within T-shaped micromixer which are ethanol-water and glycerol-water. The T-shaped micromixer consist of micro channel with two inlets channels and one outlet channel was constructed by using AutoCAD software. The effect of inlet velocity and width size toward mixing intensity were investigated. The mixing intensity values determine either good or bad mixing quality could be achieved. In this simulation, at low inlet velocity indicates good mixing quality as the mixing intensity value approaching to one. Whereas the effect of width size on mixing intensity are almost similar throughout simulated width sizes. Mixing intensity for the two cases of diffusion coefficient showed similar trend for different inlet velocity and width size of mixing channel.
      7  25
  • Publication
    Simulation-based optimization of plastic injection molding parameters for mini centrifugal pump body using response surface methodology
    Control parameters of the injection molding and fabrication process are essential to the success of any micro-molding product fabrication. The goal of the study is to simulate and optimise the parameter for the plastic mini micro centrifugal pump body by using Response Surface Methodology. The material for this micro part is Polyphenylene Sulphide (PPS). This study is also investigating the impact of design parameters and processing parameters on the quality of a plastic moulded part to obtain optimal response and meets the requirement specification. The control factors chosen for this study are melting temperature, cooling time and injection pressure. Based on the complex shape of the body part of mini micro pump, volumetric shrinkage and warpage are selected as the essential quality that needs to be controlled. The selected processing parameter are melting temperature, cooling time and injection pressure. As a result, the optimum values suggested by the software are melt temperature of 315.98 C, cooling time of 362s and injection pressure of 62MPa. With small differences error value between solution and simulation, 0.27% for volumetric shrinkage and 0.19% for warpage, the result was acceptable.
      26  3