The research for Compressed Natural Gas Direct Injection (CNGDI) vehicle has been explored recent... more The research for Compressed Natural Gas Direct Injection (CNGDI) vehicle has been explored recently. Through DI system there is an area that needs improvement on the performance outcome. The objective of this study is to investigate the influence of valve timing events on Compressed Natural Gas Direct Injection performance using 1-D simulation software. The CNGDI performance is analyzed for the converted petrol four stroke cycle, spark ignition port injection engine to CNGDI engine. The experimental on CNGDI engine is tested. The simulation model on CNGDI engine called the base model has been developed and correlated with the experimental result. By referring to the base model, the simulation model for the CNGDI is developed and calibrated. Through the CNGDI calibrated model, the valve opening and closing time on both valve has been adapted and compared with the performance result before and after the adjustment. The results are based on cylinder pressure, volumetric efficiency, engine torque and engine power with varied engine speed from 1000 to 6000rpm. The results showed better performance of CNGDI engine with less duration of valve timing events.
Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of ... more Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of diesel fuel and reduce greenhouse gas emissions because to its locked carbon cycle. However, it increases the nitrogen oxide emission, regular engine parts replacement due to clogging, and is not suitable in cold weather conditions. The addition of nanoparticles (metallic, non-metallic, oxygenated, organic and amalgamation) with diesel-biodiesel emulsion fuels results in an enhancement in the engine performance, thermo-physical properties, enrichment in the heat transfer rate, the equilibrium of the fuel mixtures and drop in the exhaust emissions reliant on the prescription of nanoparticle additives. The review intends to demonstrate the most recent nanoparticle additives used in diesel-biodiesel fuels.
An experimental and simulation flight test has been carried out to evaluate the longitudinal glid... more An experimental and simulation flight test has been carried out to evaluate the longitudinal gliding characteristics of a lifting body with blunted half-cone geometry. The novelty here is the lifting body's pitch control mechanism, which consists of a pair of leading-edge rotating cylinders. Flight simulation uses aerodynamic data from computational fluid dynamics supported by wind-tunnel test. Flight test consists of releasing an aluminum lifting body model from a moving vehicle at the appropriate wind speed while measuring the lifting body's variation of altitude against time of flight. Results show that leading-edge rotating cylinder is able to give small amounts of improvement to the longitudinal stability and pitch control to the lifting body.
IOP Conference Series: Materials Science and Engineering, 2020
The studies of simulation in biomechanical engineering using computational fluid dynamics is the ... more The studies of simulation in biomechanical engineering using computational fluid dynamics is the crucial approach nowadays for advance human surgery. The accuracy of result of simulation will help the surgery more efficient and less damage to the patient. The propose this research to investigate the most efficient number of elements could be used in validation the result of simulation of human upper airway. This research finds the 129k number of elements would give the accurate result in analysing human upper airway.
This paper aims to investigate and present the numerical investigation of airflow characteristics... more This paper aims to investigate and present the numerical investigation of airflow characteristics using Turbulent Kinetic Energy (TKE) to characterize the upper airway with obstructive sleep apnea (OSA) under inhale and exhale breathing conditions. The importance of TKE under both breathing conditions can show an accurate method in expressing the severity of flow in sleep disorder. Computational fluid dynamics are used to simulate the upper airway's airflow via steady-state Reynolds-averaged Navier-Stokes (RANS) with k–ω shear stress transport (SST) turbulence model. The three-dimensional (3D) airway model is created based on the CT scan images of an actual patient, meshed with 1.29 million elements using Materialise Interactive Medical Image Control System (MIMICS) and ANSYS software, respectively. Both high TKE and Rev were noticed around the region after the necking (smaller cross-sectional area) during the inhale and exhale breathing. The turbulent kinetic energy could be us...
The present article deals with the issue of heat and mass transfer in a square porous cavity havi... more The present article deals with the issue of heat and mass transfer in a square porous cavity having a small solid wall or block inserted at various places at bottom surface. The main objective is to investigate the effect of size of solid wall and its location inside the porous cavity on double diffusive convention. The heat and mass transfer behavior are governed by momentum, energy and concentration equations which are converted into a set of finite element equation with the help of Galerkin method. The left surface of cavity is maintained at higher temperature and concentration, T h and C h as compared to that of right surface at T c and C c . The results are presented in terms of thermal, concentration and fluid flow profiles across the porous cavity.
ADVANCES IN MECHANICAL DESIGN, MATERIALS AND MANUFACTURE: Proceeding of the Second International Conference on Design, Materials and Manufacture (ICDEM 2019), 2020
Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of ... more Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of diesel fuel and reduce greenhouse gas emissions because to its locked carbon cycle. However, it increases the nitrogen oxide emission, regular engine parts replacement due to clogging, and is not suitable in cold weather conditions. The addition of nanoparticles (metallic, non-metallic, oxygenated, organic and amalgamation) with diesel-biodiesel emulsion fuels results in an enhancement in the engine performance, thermo-physical properties, enrichment in the heat transfer rate, the equilibrium of the fuel mixtures and drop in the exhaust emissions reliant on the prescription of nanoparticle additives. The review intends to demonstrate the most recent nanoparticle additives used in diesel-biodiesel fuels.
International Journal of Numerical Methods for Heat & Fluid Flow, 2019
Purpose This paper aims to investigate the heat transfer in porous channels. Design/methodology/a... more Purpose This paper aims to investigate the heat transfer in porous channels. Design/methodology/approach Finite element method is used to simulate the heat transfer in porous channels. Findings The number and width of channels play a key role in determining the heat transfer of the porous channel. The heat transfer is higher around the channel legs. Smaller base height is better to get higher heat transfer capability. Originality/value This study represents the original work to investigate heat transfer in a porous domain having multiple channels.
The current study investigates the effect of multi stenosis on the hemodynamic parameters such as... more The current study investigates the effect of multi stenosis on the hemodynamic parameters such as wall pressure, velocity and wall shear stress in the realistic left coronary artery. Patients CT scan image data of normal and diseased left coronary artery was chosen for the reconstruction of 3D coronary artery models. The diseased 3D model of left coronary artery shows a narrowing of more than 70% and 80% of area stenosis (AS) at the left main stem (LMS) and left circumflex (LCX) respectively. The results show that the decrease in pressure was found downstream to the stenosis as compared to the coronary artery without stenosis. The maximum pressure drop was noted across the 80% AS at the left circumflex branch. The recirculation zone was also observed immediate to the stenosis and highest wall shear stress was found across the 80% area stenosis. Our analysis provides an insight into the distribution of wall shear stress and pressure drop, thus improving our understanding on the hemod...
Abstract The aim of this study is to present the effects of different Omni-direction-guide-vane (... more Abstract The aim of this study is to present the effects of different Omni-direction-guide-vane (ODGV) angles on the performance of the vertical axis wind turbine (VAWT). For this purpose, five different straight-bladed VAWTs have been simulated via three-dimensional (3D) computational fluid dynamics (CFD). Hence, the VAWT without ODGV covering, were simulated and validated via CFD and experimental fluid dynamics (EFD) data, respectively in the first step. Indeed, grid and time step independency test as well as the effect of domain size, have been conducted and a suitable agreement was found based on comparison of the CFD and EFD results. In the next step, the VAWT was shrouded by ODGV cover and the whole system was simulated for 52 angles of the ODGV in four different tip speed ratios (TSR), to investigate the impact of guide vanes angles on the VAWT performance. Results of this study indicated that output power of the VAWT with α = 20° and β = 55° ODGV guide vanes, was improved 40.9%, 36.5%, 35.3% and 33.2%, respectively in four different TSR including 0.745, 1.091, 1.901 and 2.53.
The research for Compressed Natural Gas Direct Injection (CNGDI) vehicle has been explored recent... more The research for Compressed Natural Gas Direct Injection (CNGDI) vehicle has been explored recently. Through DI system there is an area that needs improvement on the performance outcome. The objective of this study is to investigate the influence of valve timing events on Compressed Natural Gas Direct Injection performance using 1-D simulation software. The CNGDI performance is analyzed for the converted petrol four stroke cycle, spark ignition port injection engine to CNGDI engine. The experimental on CNGDI engine is tested. The simulation model on CNGDI engine called the base model has been developed and correlated with the experimental result. By referring to the base model, the simulation model for the CNGDI is developed and calibrated. Through the CNGDI calibrated model, the valve opening and closing time on both valve has been adapted and compared with the performance result before and after the adjustment. The results are based on cylinder pressure, volumetric efficiency, engine torque and engine power with varied engine speed from 1000 to 6000rpm. The results showed better performance of CNGDI engine with less duration of valve timing events.
Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of ... more Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of diesel fuel and reduce greenhouse gas emissions because to its locked carbon cycle. However, it increases the nitrogen oxide emission, regular engine parts replacement due to clogging, and is not suitable in cold weather conditions. The addition of nanoparticles (metallic, non-metallic, oxygenated, organic and amalgamation) with diesel-biodiesel emulsion fuels results in an enhancement in the engine performance, thermo-physical properties, enrichment in the heat transfer rate, the equilibrium of the fuel mixtures and drop in the exhaust emissions reliant on the prescription of nanoparticle additives. The review intends to demonstrate the most recent nanoparticle additives used in diesel-biodiesel fuels.
An experimental and simulation flight test has been carried out to evaluate the longitudinal glid... more An experimental and simulation flight test has been carried out to evaluate the longitudinal gliding characteristics of a lifting body with blunted half-cone geometry. The novelty here is the lifting body's pitch control mechanism, which consists of a pair of leading-edge rotating cylinders. Flight simulation uses aerodynamic data from computational fluid dynamics supported by wind-tunnel test. Flight test consists of releasing an aluminum lifting body model from a moving vehicle at the appropriate wind speed while measuring the lifting body's variation of altitude against time of flight. Results show that leading-edge rotating cylinder is able to give small amounts of improvement to the longitudinal stability and pitch control to the lifting body.
IOP Conference Series: Materials Science and Engineering, 2020
The studies of simulation in biomechanical engineering using computational fluid dynamics is the ... more The studies of simulation in biomechanical engineering using computational fluid dynamics is the crucial approach nowadays for advance human surgery. The accuracy of result of simulation will help the surgery more efficient and less damage to the patient. The propose this research to investigate the most efficient number of elements could be used in validation the result of simulation of human upper airway. This research finds the 129k number of elements would give the accurate result in analysing human upper airway.
This paper aims to investigate and present the numerical investigation of airflow characteristics... more This paper aims to investigate and present the numerical investigation of airflow characteristics using Turbulent Kinetic Energy (TKE) to characterize the upper airway with obstructive sleep apnea (OSA) under inhale and exhale breathing conditions. The importance of TKE under both breathing conditions can show an accurate method in expressing the severity of flow in sleep disorder. Computational fluid dynamics are used to simulate the upper airway's airflow via steady-state Reynolds-averaged Navier-Stokes (RANS) with k–ω shear stress transport (SST) turbulence model. The three-dimensional (3D) airway model is created based on the CT scan images of an actual patient, meshed with 1.29 million elements using Materialise Interactive Medical Image Control System (MIMICS) and ANSYS software, respectively. Both high TKE and Rev were noticed around the region after the necking (smaller cross-sectional area) during the inhale and exhale breathing. The turbulent kinetic energy could be us...
The present article deals with the issue of heat and mass transfer in a square porous cavity havi... more The present article deals with the issue of heat and mass transfer in a square porous cavity having a small solid wall or block inserted at various places at bottom surface. The main objective is to investigate the effect of size of solid wall and its location inside the porous cavity on double diffusive convention. The heat and mass transfer behavior are governed by momentum, energy and concentration equations which are converted into a set of finite element equation with the help of Galerkin method. The left surface of cavity is maintained at higher temperature and concentration, T h and C h as compared to that of right surface at T c and C c . The results are presented in terms of thermal, concentration and fluid flow profiles across the porous cavity.
ADVANCES IN MECHANICAL DESIGN, MATERIALS AND MANUFACTURE: Proceeding of the Second International Conference on Design, Materials and Manufacture (ICDEM 2019), 2020
Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of ... more Biodiesel is an unparalleled alternative fuel source envisioned to encompass the significance of diesel fuel and reduce greenhouse gas emissions because to its locked carbon cycle. However, it increases the nitrogen oxide emission, regular engine parts replacement due to clogging, and is not suitable in cold weather conditions. The addition of nanoparticles (metallic, non-metallic, oxygenated, organic and amalgamation) with diesel-biodiesel emulsion fuels results in an enhancement in the engine performance, thermo-physical properties, enrichment in the heat transfer rate, the equilibrium of the fuel mixtures and drop in the exhaust emissions reliant on the prescription of nanoparticle additives. The review intends to demonstrate the most recent nanoparticle additives used in diesel-biodiesel fuels.
International Journal of Numerical Methods for Heat & Fluid Flow, 2019
Purpose This paper aims to investigate the heat transfer in porous channels. Design/methodology/a... more Purpose This paper aims to investigate the heat transfer in porous channels. Design/methodology/approach Finite element method is used to simulate the heat transfer in porous channels. Findings The number and width of channels play a key role in determining the heat transfer of the porous channel. The heat transfer is higher around the channel legs. Smaller base height is better to get higher heat transfer capability. Originality/value This study represents the original work to investigate heat transfer in a porous domain having multiple channels.
The current study investigates the effect of multi stenosis on the hemodynamic parameters such as... more The current study investigates the effect of multi stenosis on the hemodynamic parameters such as wall pressure, velocity and wall shear stress in the realistic left coronary artery. Patients CT scan image data of normal and diseased left coronary artery was chosen for the reconstruction of 3D coronary artery models. The diseased 3D model of left coronary artery shows a narrowing of more than 70% and 80% of area stenosis (AS) at the left main stem (LMS) and left circumflex (LCX) respectively. The results show that the decrease in pressure was found downstream to the stenosis as compared to the coronary artery without stenosis. The maximum pressure drop was noted across the 80% AS at the left circumflex branch. The recirculation zone was also observed immediate to the stenosis and highest wall shear stress was found across the 80% area stenosis. Our analysis provides an insight into the distribution of wall shear stress and pressure drop, thus improving our understanding on the hemod...
Abstract The aim of this study is to present the effects of different Omni-direction-guide-vane (... more Abstract The aim of this study is to present the effects of different Omni-direction-guide-vane (ODGV) angles on the performance of the vertical axis wind turbine (VAWT). For this purpose, five different straight-bladed VAWTs have been simulated via three-dimensional (3D) computational fluid dynamics (CFD). Hence, the VAWT without ODGV covering, were simulated and validated via CFD and experimental fluid dynamics (EFD) data, respectively in the first step. Indeed, grid and time step independency test as well as the effect of domain size, have been conducted and a suitable agreement was found based on comparison of the CFD and EFD results. In the next step, the VAWT was shrouded by ODGV cover and the whole system was simulated for 52 angles of the ODGV in four different tip speed ratios (TSR), to investigate the impact of guide vanes angles on the VAWT performance. Results of this study indicated that output power of the VAWT with α = 20° and β = 55° ODGV guide vanes, was improved 40.9%, 36.5%, 35.3% and 33.2%, respectively in four different TSR including 0.745, 1.091, 1.901 and 2.53.
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Papers by N.N.N. Ghazali