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
    Statistical analysis on the near-wake region of RANS turbulence closure models for vertical axis tidal turbine
    ( 2022)
    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
  • 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
  • Publication
    Investigating the thermal characteristic of copper alloys valve seat towards engine performance enhancement of MODENAS CT115 through steady-state analysis
    ( 2021-10-25)
    Zainol M.A.A.
    ;
    Mohamad Aniq Syazwan Mohamed Hassan
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    Anas Abdul Rahman
    ;
    Mohd Sani Mohamad Hashim
    ;
    Nur Saifullah Kamarrudin
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Azizi Harun
    ;
    Ishak Ibrahim
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Muhammad Faiz Hilmi Rani
    MODENAS CT115 engine is a single overhead camshaft (SOHC) engine, with a rated power of 8.8 horsepower at 9000 rpm. One of the main concerns of engine research is the overheating of engines. Overheating can affects the performance of an engine by leading to a loss of strength and thermal strain. To prevent failure, thermal analysis is used to determine the flow of heat with precision to optimise temperature distribution. The investigation is done using ANSYS Thermal simulation on the CAD model of the engine cylinder head, intake and exhaust valve, and intake and exhaust valve seat insert. The comparison to the existing valve seat insert is made using three different valve seat insert materials: Beryllium-copper C17200, Bronze-copper C61300, and Brass C36000. The research results proved that Brass C36000 provides the best thermal reduction and heat transfer increment compared to the existing valve seat insert material.
  • 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.
  • 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.
  • Publication
    Study on modal and harmonic response analysis by modifying motorcycle chassis using finite element method
    ( 2021-10-25)
    Wong Y.J.
    ;
    Mohd Sani Mohamad Hashim
    ;
    Shahriman Abu Bakar
    ;
    Anas Abdul Rahman
    ;
    Aziz I.A.
    ;
    Mohd Asrul Md Saad
    ;
    Nasirudin M.A.
    ;
    Zuradzman Mohamad Razlan
    ;
    Nur Saifullah Kamarrudin
    ;
    Ishak Ibrahim
    ;
    Mohd Khairul Faizi Abd Rahman
    Motorcycle chassis is one of the most important structures in the design of a motorcycle. Excessive vibration occurs in chassis is undesirable as it may lead to structural failure and discomfort among riders. This study aims to model the motorcycle chassis and carry out dynamic analysis to understand the behaviour of the chassis under vibration. Modelling of chassis was conducted based on Seri Perlis motorcycle, which is characterised by double cradle frame. In dynamic analysis, the modal and harmonic response analysis were employed in this study of the motorcycle chassis and the material used is low carbon steel. Both modal and harmonic response analysis were conducted using Ansys. The results show natural frequencies for six mode shapes and the steady-state response of the chassis under the engine weight excitation revealed that the deformation under z-axis orientation was more prevalent. From this study, the dynamic behaviour of the chassis was understood and improvement of the chassis can be made in the future.
  • 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.
  • 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.
  • Publication
    Temperature measurement methods in an experimental setup during bone drilling: A brief review on the comparison of thermocouple and infrared thermography
    ( 2021-12-14)
    Islam M.A.
    ;
    Nur Saifullah Kamarrudin
    ;
    Ruslizam Daud
    ;
    Ishak Ibrahim
    ;
    Anas Abdul Rahman
    ;
    Fauziah Che Mat
    Predicting thermal response in orthopedic surgery or dental implantation remains a significant challenge. This study aims to find an effective approach for measuring temperature elevation during a bone drilling experiment by analyzing the existing methods. Traditionally thermocouple has frequently been used to predict the bone temperature in the drilling process. However, several experimental studies demonstrate that the invasive method using thermocouple is impractical in medical conditions and preferred the thermal infrared (IR) camera as a non-invasive method. This work proposes a simplified experimental model that uses the thermocouple to determine temperature rise coupled with the thermal image source approach. Furthermore, our new method provides a significant opportunity to calibrate the thermal IR camera by finding out the undetected heat elevation in a workpiece depth.