Mohd Al-Hafiz Mohd Nawi
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Preferred name
Mohd Al-Hafiz Mohd Nawi
Official Name
Mohd Al-Hafiz , Mohd Nawi
Alternative Name
Hafiz, M. A.
Nawi, M. A.H.M.
Nawi, M. A.M.
Nawi, Mohd Al Hafiz Mohd
Nawi, M. H.
Main Affiliation
Scopus Author ID
57195980205
Researcher ID
IOU-7551-2023

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  • Publication
    Effect of twist blade distributor on velocity distribution in a swirling fluidized bed
    ( 2020-12-18)
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Suhaida Rasman S.N.
    ;
    Mohd Riduan Jamalludin
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    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.
  • Publication
    Simulation Analysis of the Thickness Effect towards Mechanical Aspects in the Design of Centrifugal Pump Casing
    ( 2020-07-09)
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Muhammad Ikman Ishak
    ;
    Ooi Z.K.
    ;
    Mohd Uzair Mohd Rosli
    ;
    Siti Nor Azreen Ahmad Termizi
    The strength of the centrifugal pump is crucial to ensure the safe pump operating when endure to unintended pumping condition. The presence of the solid particles and sudden increase of pressure may lead to the damage on the casing of a centrifugal pump and it becomes critical when the thickness of the casing is thin. This study aims to investigate the effects of the thickness on the mechanical aspects such as stress, strain and displacement in the casing design by using finite element (FE) analysis. The structure of the pump casing with various thicknesses is analyzed via FE-based software. The correlation of the wall thickness with the mechanical aspects is studied. The critical region with high stress was spotted in the simulation. The simulation results revealed the wall thickness demonstrated a polynomial correlation to the displacement and strain. The stress of the casing showed the linear correlation with the thickness. The critical region was noticed at the intersection region of the pump casing. The mechanical aspects of the pump casing were improved with the increment of the wall thickness in the pump casing design.
  • Publication
    A Short Review on Multi-stage Application in Fluidization Systems
    ( 2021-01-01)
    Silmie M.S.M.
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Faris M.A.
    ;
    Marzuki M.A.B.
    This research focuses on the implementation of an approach of multi-stage in fluidization systems in various aspects. The multi-stage fluidized bed has been proposed to improve the process and function of fluidization systems based on the current of the single-stage methods. The detailed of single-stage fluidization interaction method provides a realistic visualization of airflow and fluidization system interaction. In this article, a variant application, involving in multi-stage fluidized bed has been reviewed. In a few articles were analyzed, each manuscript was evaluated based on the scientific work via fluidization systems. The experimental study and analysis of airflow characteristics was a valuable tool to understand this phenomenon of the multi-stage fluidized bed process. Then the parameter, flow properties, activities of the multi-stage fluidized bed systems have been considered to the current swirling fluidized bed being applied to study. As a result of this short review, each multi-stage fluidized bed has its capability and suitability for its products and studies. Finally, the concentration of multi-stage fluidized bed is also highlighted in these manuscripts.
  • Publication
    Numerical Simulation of Biodiesel Synthesis in T- Channel Microreactor
    ( 2020-07-09)
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Syafiqah Binti Mohd Aris N.
    ;
    Muhammad Ikman Ishak
    ;
    Rosli M.U.
    Biodiesel promising as an alternative to the diesel. The transesterification reaction process involved the reaction of triglyceride with alcohol in the presence of catalyst. In the research, the Computational Fluid Dynamic (CFD) method was used to simulate the transesterification reaction process. The inlet pressure range from 0.0001 Pa to 0.01 Pa, temperature of 25°C, 50°C, 75°C and the molar ratio at 6:1, 9:1 were used to investigate their effect of toward the biodiesel conversion. Finding shows that high conversion of biodiesel occurred at low inlet pressure of 0.001 Pa with temperature of 50°C and the ethanol to oil molar ratio at 9:1.
  • Publication
    Computational fluid dynamics (CFD) simulation on mixing in Y-shaped micromixer
    ( 2020-11-02)
    Siti Nor Azreen Ahmad Termizi
    ;
    Ishak M.I.
    ;
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Pouzay M.F.B.M.
    Computational Fluid Dynamics (CFD) is used to analyse the mixing process inY-shaped micromixer. This study used two different species which is ethanol/water and glycerol/water to see the differences of mixing quality between them based on their diffusion coefficient. The effect of the inlet velocity and mixing angle towards the mixing intensity in the Y-shaped micromixer were investigated via COMSOL Multiphysics software. Mixing intensity quantify the mixing performance is good or bad for every parameter simulated. The finding shows that the lower the inlet velocity, the higher the mixing intensity across the micromixer. The good mixing quality was at inlet velocity of 0.0001m/s while the ideal mixing angle was 90° degree. However, the mixing quality in term of diffusion coefficient, ethanol/water and glycerol/water shows insignificant differences.
  • Publication
    Biomechanical assessment of different surgical approaches of zygomatic implant placement on prosthesis stress
    ( 2020-12-18)
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Mohd Riduan Jamalludin
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    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.
  • Publication
    Mechanical Design and Analysis of Safety Medical Syringe for Needlestick Injury Prevention
    ( 2021-01-01)
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Mohd N.A.
    ;
    Mohd Al-Hafiz Mohd Nawi
    The occurrence of needlestick injury especially among healthcare workers and patients is really significant since long time ago. Apart from improper syringe usage management, the reuse syringe components and unsafe sharp wastes management also contribute to the incidence of unexpected injuries. It was reported that one of every 250 accidental needlesticks may result in the infection of human immunodeficiency viruses (HIV), Hepatitis B (HBV), or Hepatitis C (HCV). Based on the user needs identification, promising safety mechanism and handling as well as single use of the syringe are of major interests. Thus, the aim of the study was to design and develop a new syringe that completed with safety and ergonomic features to avoid the related injuries. Primary and secondary data had been collected through interview, observation and journal articles with a series of design concept development, three-dimensional (3-D) modelling, and computational technical evaluation stages were then undertaken. A number of mock-ups and prototype of the product was produced via rapid prototyping process which is 3-D printing approach using acrylonitrile butadiene styrene (ABS) as the material. The results showed that the proposed design of safety syringe is satisfactory in terms of its structural strength and working principle. Further enhancement may be necessary to strengthen the role of the material and needle cap in compensating the function of the syringe.
  • Publication
    Influence of Twisted Blades Distributor Towards Low Pressure Drop in Fluidization Systems
    ( 2021-01-01)
    Zulkifli R.M.
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Rosli M.U.
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Faris M.A.
    Swirling Fluidized Bed (SFB) is one of the systems that proposed vortexing to solid mixing due to a given gas source which impart on the solid mixing. This system is usually be used in the power generation, chemical industry, material production and drying processes. However, the used of blade distributor in SFB is still produced high-pressure drop even though it has been claimed the successful variant in fluidization systems. By using an annular blade distributor in a twist, the condition will cause in low-pressure drop and keep the energy consumption of a fluidized bed system in high efficient. The simulation study using Computational Fluid Dynamics (CFD) has been selected to investigate to the behaviour of velocity component and to determine the effects of the plenum chamber (axial entry) on airflow behaviour via twist blade distributor configurations. This study uses two (2) twist angle (80 and 100°) via several blade number 40, 50 and 60. Therefore low-pressure drop and high uniform velocity has be the main goal in this observation. The result of this study found that design on 100° twist angle via 40 number of blades distributor shows low a pressure drop besides being able to maintain the high airflow uniformity compared to other configurations.
  • Publication
    Simulation Based Optimization of Thin Wall Injection Molding Parameter Using Response Surface Methodology
    ( 2020-07-09)
    Rosli M.U.
    ;
    Siti Nor Azreen Ahmad Termizi
    ;
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Akmal Omar A.
    ;
    Muhammad Ikman Ishak
    Improper mold design or processing parameter setting could make a bad impact on the appearance of molded part. It becomes more challenging if the ratio of the part size compared with its wall thickness is greater. Process parameters such as mold and melt temperature, injection temperature including the cavity layout directly affect product quality and cost. It is a complex and difficult task to improve these multi parameters. The objective of this research is to determine optimum settings for processing parameters for a thin walled product by using Response Surface Methodology. Melting temperature, mold temperature, injection pressure and cavity layout are selected as processing parameters and Polyurethane material is selected for this research. Volumetric shrinkage and warpage are selected as the main quality criteria to be controlled respected with the product design specifications. As the result, optimum process parameter settings were mold temperature of 29.89°C, melting temperature of 220°C, and 181.30MPa injection pressure with 'H' branching cavity layout. With small differences error value between solution and simulation, 0.31% for volumetric shrinkage and 0.126% for warpage, the result was acceptable.
  • Publication
    Effect of heat sink design on the thermal characteristic in computational fluid dynamics analysis
    ( 2020-12-18)
    Khor Chu Yee
    ;
    Mohd Al-Hafiz Mohd Nawi
    ;
    Ishak M.I.
    ;
    Kee W.C.
    ;
    Rosli M.U.
    ;
    Mohd Riduan Jamalludin
    ;
    Siti Nor Azreen Ahmad Termizi
    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.