Anas Abdul Rahman
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Preferred name
Anas Abdul Rahman
Official Name
Anas, Abdul Rahman
Alternative Name
Rahman., A. A.
Rahman, Anas
Rahman, A. A.
Rahman, Anas Abdul
Main Affiliation
Scopus Author ID
57193557057
Researcher ID
P-9313-2018

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  • Publication
    Tensile characterizations of oil palm empty fruit bunch (Opefb) fibres reinforced composites in various epoxy/fibre fractions
    ( 2022-10-15)
    Mohd Khairul Faizi Abd Rahman
    ;
    Shahriman Abu Bakar
    ;
    Mohd Shukry Abdul Majid
    ;
    Tamrin S.B.M.
    ;
    Israr H.A.
    ;
    Anas Abdul Rahman
    ;
    Guan N.Y.
    ;
    Zuradzman Mohamad Razlan
    ;
    Kamis N.A.
    ;
    Wan Khairunizam Wan Ahmad
    Oil palm empty fruit bunch (OPEFB) single fibers and reinforced composites were comprehensively characterized through tensile tests to assess their performance as potential reinforcing materials in polymer composites. The performances of OPEFB single fibers and reinforced composites with untreated and treated fibers conditions were compared. The fibers were variously treated with 3% sodium hydroxide, 2% silane, 3% sodium hydroxide mixed with 2% silane, and 3% sodium hydroxide prior to 2% silane for 2 hours soaking time. The highest toughness of the single fibers test was then selected to proceed with composites fabrication. The OPEFB composites were fabricated in 90:10, 80:20, 70:30, and 60:40 epoxy-fibre fractions. The result shows that the selected treated fiber composite exhibits better performance. The selected treated fiber composite increased the highest ultimate tensile strength by 145.3% for the 90:10 fraction. The highest Young’s Modulus was increased by about 166.7% for 70:30 fraction. Next, the highest toughness was increased by 389.5% for the 30:70 fraction. The treated fibers provided a better interlocking mechanism between the matrix and fibers in reinforced composites, thus improving their interfacial bonding.
  • Publication
    Numerical study of ducted turbines in shallow water environment
    (Penerbit UTHM, 2023)
    Azzim Rosli
    ;
    Anas Abdul Rahman
    ;
    Ayu Abdul-Rahman
    ;
    Najwa Syafiqa Marzuki
    ;
    Wan Muhammad Fadhli
    ;
    Syafiq Misran
    ;
    Ramadhan Ahmed Ramadhan Basiddiq
    The development of tidal turbines, particularly for shallow water applications, is still in its early stages. Vertical axis tidal turbines (VATT) are often preferred for shallow water due to the bidirectional nature of tidal currents. Implementing a channelling system around a tidal turbine can significantly stabilise the flow field, increase the current velocity, and enhance the energy efficiency of the turbine. However, there has been limited exploration of using channelling techniques to improve the performance of VATTs in turbid areas. This study employs a numerical analysis using computational fluid dynamics (CFD) to investigate VATTs. The VATT model is represented by a cylindrical object with a diameter and height of 5 meters. The simulation focuses on the wake characteristics and the design of turbine arrays. The Reynolds-Averaged Navier-Stokes (RANS) equations are utilised as flow viscous solvers in ANSYS Fluent, and the effectiveness of the ducts in energy conversion is calculated using the realizable two-layer turbulence model. The primary objective of this study is to examine the impact of converging devices on tidal turbine performance and propose an optimal design for shallow water applications. The proposed ducted design shows an increase in current speed passing through the device by 11.1%. Although the wake generated by the multi-row staggered array layout disperses the flow to the side of the domain, the model demonstrates a 0.9% improvement in velocity magnitude. Conversely, the results for the single-row inline layout indicate the most favorable arrangement for shallow water applications, with a 19.4% increase in velocity magnitude and a shorter wake generation.
  • Publication
    Analysis of temperature and relative humidity distributions in a dental treatment room at a government health clinic in Malaysia
    (Semarak Ilmu Publishing, 2025)
    Mohamad Nazrin Yahaya
    ;
    Zuradzman Mohamad Razlan
    ;
    Eswanto Eswanto
    ;
    Naoki Maruyama
    ;
    Anas Abdul Rahman
    ;
    Muhd Nur Rahman Yahya
    ;
    Shahriman Abu Bakar
    ;
    Muhammad Faiz Hilmi Rani
    This study investigates the vertical distribution of temperature and relative humidity within dental treatment rooms at a Government Type 3 Health Clinic in Gial Perlis, Malaysia, addressing a significant gap in the literature regarding environmental conditions in dental healthcare settings. Precise measurements were conducted at four specific heights 0.3 m, 1.0 m, 1.7 m, and 2.7 m utilizing calibrated digital thermometers with hygrometers to capture accurate environmental data. The collected data were analysed using Analysis of Variance (ANOVA) to assess the significance of variations across these levels. Results revealed statistically significant differences in both temperature and relative humidity (p < 0.05). At the uppermost level (2.7 m), the highest mean temperature of 22.1°C and a mean relative humidity of 68.2% were recorded, while the lowest level (0.3 m) exhibited the lowest mean temperature of 20.9°C and the highest mean relative humidity of 73.8%. Temperatures at the patient level (1.0 m and 1.7 m) averaged between 21.0 °C and 21.6°C, which is slightly below the optimal comfort range of 22°C to 26°C. These vertical gradients indicate that the existing HVAC systems may not be effectively regulating indoor conditions, potentially impacting patient comfort, the performance of temperature-sensitive dental materials, and the effectiveness of infection control measures due to altered aerosol behaviour. The findings underscore the necessity of optimizing HVAC designs to achieve uniform temperature and humidity distributions within dental treatment rooms. This research provides valuable insights for healthcare professionals and policymakers, emphasizing the importance of tailored environmental management strategies to enhance patient comfort, procedural outcomes, and safety in dental healthcare settings.
  • Publication
    Improvement of Dissolved Oxygen in Perlis River based on Various Aeration Systems
    ( 2021-12-14)
    Muhammad Faiz Hilmi Rani
    ;
    Nur Saifullah Kamarrudin
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Mohd Sani Mohamad Hashim
    ;
    Ishak Ibrahim
    ;
    Anas Abdul Rahman
    ;
    Ibrahim Z.
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Mohamad Aniq Syazwan Mohamed Hassan
    ;
    Abd Manap A.A.
    ;
    Zainuddin I.F.
    Water pollution is closely related to the Water Quality Index (WQI). One of the parameters in classifying WQI is dissolved oxygen (DO) that can be improved by introducing the surface and subsurface aerations. Herein, the Perlis River's water quality was investigated by evaluating the DO's improvement based on various aeration systems. The changes of DO (mg/L) and DO improvement (%) were evaluated during both low and high tide conditions. A total of 9 sets of data collection had been studied by comparing base DO (without running of aeration) and measured DO (with running of aeration) of river. The DO sensor was used to measure the changes of DO in the aeration measurement system. Results found that the DO improvement managed to achieve 74.89%, 10.18%, 35.58%, and 52.45% for water jet, air compressor, commercial venturi, and DIY venturi, respectively. Besides, different behaviour of DO's improvement was observed during low and high tide conditions.
      5  42
  • Publication
    Statistical Analysis on The Near-Wake Region of RANS Turbulence Closure Models for Vertical Axis Tidal Turbine
    ( 2023-01-01)
    Rahim M.W.A.
    ;
    Anas Abdul Rahman
    ;
    Abdul-Rahman A.
    ;
    Muhammad Izham Ismail
    ;
    Mohd Shukry Abdul Majid
    ;
    Nasrul Amri Mohd Amin
    The flow field in the near wake region (up to six turbine diameters downstream) of a tidal current turbine is strongly driven by the combined wake of the device support structure and the rotor. Accurate characterisation of the near-wake region is important, but it is dominated by highly turbulent, slow-moving fluid. At present, limited number of researches has been undertaken into the characterisation of the near-wake region for a Vertical Axis Tidal Turbine (VATT) device using the Reynolds Averaged Navier Stokes (RANS) model in the shallow water environment of Malaysia. This paper presents a comprehensive statistical analysis using the Mean Absolute Error (MEA), Mean Squared Error (MSE) and Root Mean Squared Error (RMSE) on the near-wake region for shallow water application by comparing numerical solutions (i.e., different types of RANS turbulence models using Ansys Fluent) with published experimental data. Seven RANS turbulence models with a single VATT, represented by using a cylindrical object, were employed in the preliminary study. The statistical analysis performed in this study is essential in exploring and giving a detailed understanding on the most suitable RANS turbulence model to be improved, specifically on its near-wake region. In this study, the near wake region is defined as D ≤ 6, where D is the device diameter. The analysis shows that the RANS numerical solutions are unable to accurately replicate the near-wake region based on large statistical errors computed. The average RMSE of near-wake region at z/D = [2, 3, 4, 6] are 0.5864, 0.4127, 0.4344 and 0.3577 while the average RMSE at far-wake region z/D = [8, 12] are 0.2269 and 0.1590, where z is the distance from the cylindrical object along the length of domain. The statistical error values are found to decrease with increasing downstream distance from a cylindrical object. Notably, the standard k–ε and realizable k–ε models are the two best turbulent models representing the near-wake region in RANS modelling, yielding the lowest statistical errors (RMSE at z/D = [2, 3, 4, 6] are 0.5666, 0.4020, 0.4113 and 0.3455) among the tested parameters.
      28  2
  • Publication
    Derivation and validation of heat transfer model for Spark-Ignition engine cylinder head
    ( 2023-05-05)
    Hassan M.A.S.M.
    ;
    Zuradzman Mohamad Razlan
    ;
    Shahriman Abu Bakar
    ;
    Anas Abdul Rahman
    ;
    Mohd Afendi Rojan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Ibrahim Z.
    ;
    Ishak A.A.
    ;
    Mohd Ridzuan Mohd Jamir
    The valve train is located in the engine cylinder head, which has various operational heat transfer mechanisms to accommodate the combustion process. Most heat transfer studies in this area have only addressed medium-to high-power vehicles at a single running speed. In this study, a model of an air-cooled underbone motorcycle valve, valve seat, and engine cylinder head was tested to determine the thermal characteristics using actual engine operating conditions at low, medium, and high engine speeds. One-dimensional thermal simulation analyses were conducted to obtain the instantaneous heat-transfer coefficients of an actual engine. The average thermal value was determined as the boundary condition in the three-dimensional thermal analysis. A three-dimensional model was prepared using the ANSYS commercial computational fluid dynamics software package. The results show that as the engine speed increases, so does the thermal load toward the component in the engine cylinder head. The strongest temperature regions were concentrated around the combustion face. The exhaust valve held most of the heat, with the valve neck recording the highest temperature. For the intake valve, the combustion face registered the majority of the heat. The heat flux intensity was gathered in the contact surface area between the valve and its seat, between the valve stem and guide, and between the stem guide and tip section. A thermal survey was used to validate the three modelling results for two separate engine datasets. The cumulative relative errors for intake and exhaust valve seats for low engine speeds were 3.73% and 0.17%, respectively. The intake and exhaust valve seats had cumulative relative errors of 4.12% and 0.70%, respectively, at intermediate speeds. This methodology provides valuable information for analysing the heat characterisation of air-cooled engines. It can also be a useful blueprint for the automotive industry and other researchers involved in thermal measurements.
      32  2
  • Publication
    Engine Performance Analysis by Studying Heat Transfer in the Valve Seat through Steady-State Thermal Simulation
    ( 2021-12-14)
    Mohamad Aniq Syazwan Mohamed Hassan
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    Nur Saifullah Kamarrudin
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Mohd Sani Mohamad Hashim
    ;
    Azizi Harun
    ;
    Ishak Ibrahim
    ;
    Azizul Aziz I.
    ;
    Zunaidi Ibrahim
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Muhammad Faiz Hilmi Rani
    ;
    Anas Abdul Rahman
    ;
    Mohd Afendi Rojan
    ;
    Rishan Murali
    As the engine reached high speed, the exhaust valve temperature increased exponentially due to the exhaust gas produced by the combustion process between the mixture of air and fuel within the combustion chamber of the internal combustion engine. The valve is subjected to thermal loading due to high temperature and pressure within the cylinder, which must withstand a material temperature for sustainable and optimal operation. To avoid this loss, a perfect medium must be prepared to ensure that the heat is extracted smoothly. This can be done when the valve is in contact with the seat and there is a periodic heat transfer contact. Therefore, it is imperative to research the correlation between valve and valve seat to understand the two sections' heat transfer mechanism. In this study, thermal contact analysis was used to identify heat transfer between the valve and the valve seat as both parts are interconnected. This research also has an interest in studying the two surface conduction mechanisms as the exhaust valve closed in steady-state conditions. Thus, this study portrays a significant method, particularly for the determining the distribution of temperature, heat flux, and heat flux direction between the valve and its seat using ANSYS Workbench.
      2
  • Publication
    CFD Simulation on Improving Water Quality based on Various Aerator Models to Demonstrate Cost Performance Analysis
    ( 2021-12-14)
    Nazrul Najmi Norbashah
    ;
    Muhammad Faiz Hilmi Rani
    ;
    Nur Saifullah Kamarrudin
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Mohd Sani Mohamad Hashim
    ;
    Ishak Ibrahim
    ;
    Anas Abdul Rahman
    ;
    Ibrahim Z.
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Mohamad Aniq Syazwan Mohamed Hassan
    ;
    Abd Manap A.A.
    ;
    Zainuddin I.F.
    There are many types of aerator that can be used to perform a water treatment process either from air to water or from water to air approaches. Other than focusing on the performance itself, the usage cost of aerator should be forecasted in detail too to have a sustainable and economical method in remediating the polluted water. Therein, the cost performance analysis was demonstrated by performing a computational fluid dynamics (CFD) simulation on improving water quality based on various aerator models. The simulation was focused in a small-scale aeration tank that consists of a mixing chamber, air duct, and a few of bubble diffusers. The improvement of water quality was assessed by calculating the number of gas bubble particles produced by 4 different configurations of aerator model, namely aerator model A, B, C and D, respectively. Results found that the aerator model D (5 bubble diffuser at 620 L/min) produces the highest number of gas particles up to 72.2%. However, the aerator model C (5 bubble diffuser at 300 L/min) was found to achieve the most efficient and sustainable approach based on energy consuming and cost of aerator configuration when compared to the other aerator models.
      3  37
  • Publication
    Development of a Novel Aeration Measurement System to Evaluate Water Treatment Process in a River
    ( 2021-12-14)
    Muhammad Faiz Hilmi Rani
    ;
    Nur Saifullah Kamarrudin
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Mohd Sani Mohamad Hashim
    ;
    Ishak Ibrahim
    ;
    Anas Abdul Rahman
    ;
    Ibrahim Z.
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Mohamad Aniq Syazwan Mohamed Hassan
    ;
    Abd Manap A.A.
    ;
    Zainuddin I.F.
    A novel aeration measurement system was developed to evaluate the water treatment process in a river to acquire a more comparable dissolved oxygen value even if various types of aerations are tested. The system comprises of DO sensor, water flowmeter, anemometer, PVC pipes, water pump, air compressor pump, and truck tyre tubes. The PVC pipes consisting of a main drainage hole, 5 holes for dissolve oxygen data collection, 1 hole as the location of aerator system, and connectors were designed as the major part of the system by using Computer Aided Design software. The main drainage hole (horizontal pipe) was designed to be 288.5 cm in length, while the measured holes (vertical pipes) were designed to be 45.7 cm in height. By considering a systematic approach, the designed system is hopefully able to solve measuring issue of dissolved oxygen in moving water and to provide a better evaluation of water treatment process.
      1  34
  • Publication
    Statistical analysis on the near-wake region of RANS Turbulence Closure Models for Vertical Axis Tidal Turbine
    ( 2023-01-01)
    Muhammad Wafiuddin Abd Rahim
    ;
    Anas Abdul Rahman
    ;
    Ayu Abdul-Rahman
    ;
    Muhammad Izham Ismail
    ;
    Mohd Shukry Abdul Majid
    ;
    Nasrul Amri Mohd Amin
    The flow field in the near wake region (up to six turbine diameters downstream) of a tidal current turbine is strongly driven by the combined wake of the device support structure and the rotor. Accurate characterisation of the near-wake region is important, but it is dominated by highly turbulent, slow-moving fluid. At present, limited number of research has been undertaken into the characterisation of the near-wake region for a Vertical Axis Tidal Turbine (VATT) device using the Reynolds Averaged Navier Stokes (RANS) model in the shallow water environment of Malaysia. This paper presents a comprehensive statistical analysis using the Mean Absolute Error (MEA), Mean Squared Error (MSE) and Root Mean Squared Error (RMSE) on the near-wake region for shallow water application by comparing numerical solutions (i.e., different types of RANS turbulence models using Ansys Fluent) with published experimental data. Seven RANS turbulence models with a single VATT, represented by using a cylindrical object, were employed in the preliminary study. The statistical analysis performed in this study is essential in exploring and giving a detailed understanding on the most suitable RANS turbulence model to be improved, specifically on its near-wake region. In this study, the near wake region is defined as D ≤ 6, where D is the device diameter. The analysis shows that the RANS numerical solutions are unable to accurately replicate the near-wake region based on large statistical errors computed. The average RMSE of near-wake region at z/D = [2, 3, 4, 6] are 0.5864, 0.4127, 0.4344 and 0.3577 while the average RMSE at far-wake region z/D = [8, 12] are 0.2269 and 0.1590, where z is the distance from the cylindrical object along the length of domain. The statistical error values are found to decrease with increasing downstream distance from a cylindrical object. Notably, the standard k–ε and realizable k–ε models are the two best turbulent models representing the near-wake region in RANS modelling, yielding the lowest statistical errors (RMSE at z/D = [2, 3, 4, 6] are 0.5666, 0.4020, 0.4113 and 0.3455) among the tested parameters
      1  28