Search

This research compare three different types of Crude Palm Oil (CPO) biodiesel blends, B5, B10, and B15 with different ambient density on nozzle flow and spray characteristics by using CPO and simulated the physics flow pattern of mixture formation with tangential velocity between biodiesel, diesel fuel, and air in the mixing chamber of RCM, to determine the nozzle flow and spray characteristics for different injection pressure of biodiesel spray to ambient variant conditions on mixture formation. In order to mimic the spray processes, an Eulerian-Lagrangian multiphase technique is presented in this study. This work makes use of Computational Fluid Dynamics (CFD) Fluent to examine the spray properties of biodiesel fuels, and the simulation took biodiesel injection into the constant volume chamber of the RCM into account. The boundary condition is set up at a distinct ambient parameter. The presence of in-cylinder flow, the impact of fuel type, injection pressure, and ambient variables on spray behaviour, such as spray penetration, had been examined. Analysis of the spray penetration variation with time for various ambient parameters and different types of biodiesel fuels revealed that the biodiesel fuels were predicted to develop their break-up more quickly due to the fact that all fuels atomize more quickly in the presence of higher injection pressures. The effects of these various parameters were examined in terms of spray characteristics and contrasted with the findings of the experiments

Diesel engine performance and emission rely greatly on the diesel spray. A lot of researches conducted to study the diesel spray characteristics in a closed chamber. However, it cannot describe in detail about the phenomenon since the chamber condition such as pressure and size play a role in s pray characteristics. It would be beneficial to conduct an experiment in open chamber. Hence, this research would develop a new experiment apparatus and analyze the diesel spray characteristics in open chamber. In this research, common - rail injector tester is used to simulate the actual common - rail injection diesel engines. The injection pressure is varied from 100MPa to 180MPa. A high speed camera with 3,000 frames per second is used to capture the diesel spray formation using direct photography technique. From the result, spray development angle, and fully developed spray angle is studied. The results revealed early at the injection, the spray angle increased swiftly before slowly decreased as reaching fully developed spray phase. At the fully developed phase, spray angle proved to be decreased as the injection pressure increased.

Fire Safety Engineering is an application of science to improve the safety from the destructive effect of the fire. Paper is well known as a material that can easily catch fire. Nowadays, many researchers have been interested to produce paper by using other natural fiber to reduce the usage of wood as raw material for paper production. However, research on flame spread towards combination paper / natural fiber is still a lack of data. Inspiration from this, the behavior of downward flame spread over paper and bagasse is experimentally investigated. This experiment is conducted by using the specimen with different thickness and different composition of bagasse. Specimen thickness is chosen at 0.7mm, 1.4mm, 2.1mm and 2.8mm; while for bagasse composition is 0%, 30%, 50%, 70% and 100%. Flame spread behavior for each specimen is videotaped by using a camera. The result showed that the flame spreads with “U” pattern at the beginning of the combustion, but end up with different pattern according to thickness and composition of bagasse. It is seen that flame spread rate decreases with increasing the thickness and composition of bagasse for the specimen. The result also shows that up to 70% bagasse, the flame spread rate is approximately constant even for different thickness.

Improvements in the diesel fuel injection systems can provide efficient combustion in internal combustion engine. However, the detail relationship between the diesel injector nozzle cavitation parameters are still remain unclear. The main goal of this research is to verify the flow characteristics inside the fuel injector nozzle by using CFD. A computational fluid dynamics cavitation models of diesel injector nozzles is presented and tested. Then, the experimental data are used to validate the models. The researcher used the same shape configeration and boundary condition. The injection event is inherently transient, as the injection pressure varies with the needle lift position. In order to capture this transient aspect within a steady-state formulation, this study performed simulations for different lift positions for the base nozzle. The results is done for the flow distribution for needle lift positions at 0.275 mm, 0.2 mm, 0.15 mm, and 0.1 mm. The corresponding velocity vector is plotted in order to explain the transient cavitation behavior. The velocity vectors for needle lift=0.275 mm indicate that the flow entering the orifice encounters a sharp bend (i.e., large velocity and pressure gradients) at the top of the orifice inlet causing cavitation in this region, However, with needle lift position at 0.15 mm, the flow entrance into the orifice is relatively smooth.

Performance of microelectronic devices has been greatly enhanced owing to the development of the very large-skill technology. However, with the increase of circuit density and operating speed, more heat was generated by the microelectronics devices. So, the objective of this project is to do a comparative study between two different types of fractal microchannel at the same size and boundary condition by using Computational Fluid Dynamics (CFD) Besides that, this study also will investigate the hydrodynamic and thermal characteristics of T-shaped and Treeshaped fractal microchannel network heat sinks by solving three-dimensional Navier– Stokes equations and energy equation, taking into consideration the conjugate heat transfers in microchannel walls. For the simulation, ANSYS software was used with the inlet temperature set to be 300 K, inlet velocity will be in the range of 0.1 m/s to 0.5 m/s and uniform heat flux be set at 325 W/cm2. From this study, it was found that due to the structural limitation of right-angled fractal-shaped microchannel network, hotspots may appear on the bottom wall of the heat sink where the microchannel are sparsely distributed. With slight modifications in both fractal-shaped structure of microchannel network, great improvements on the hydrodynamic and thermal performance of heat sink can be achieved. A comparison of the performance of modified fractal-shaped microchannel network heat sink with parallel microchannel heat sink is also conducted numerically based on the same heat sink dimensions. It is found that the modified fractal-shaped microchannel network is much better in terms of thermal resistance and temperature uniformity under the conditions of the same pressure drop or pumping power. Therefore, the modified fractal-shaped microchannel network heat sink appears promising to be used for microelectronic cooling in the future.

Separation of the boundary layer over an airfoil causes a significant increase in the adverse pressure gradients and the losses of energy resulting in the reduction of the lift force and the increment of drag force. Therefore, delaying and eliminating flow separation is necessary to improve its aerodynamic characteristics. In this study, an injection of flow was introduced at the upper surface/suction side of the aerofoil to control the boundary layer separation effectively. Flow around the NACA0012 airfoil was examined, with the position of flow injection jet at 90° relative to the tangential surface of the airfoil at 20%, 50% and 80% of its chord length. The flow injection velocity was varied from 0%, 10%, 30% and 50% of the free stream velocity, which corresponds to 0, 2.5 x 10-4, 2.25 x 10-3 and 6.25 x 10-3 of the momentum coefficient. The results showed that the most suitable condition was at 10% of the blowing amplitude (2.5 x 10-4 of the momentum coefficient) of flow injection at the trailing edge, which was around 80% of the chord length at the upper surface/suction side. This configuration can successfully increase the lift force and decrease the drag force of the aerofoil at the angle equal to or larger than a stall angle of 16° compared to the baseline aerofoil.

Occupational Safety and Health Act (OSHA) is a discipline with broad scope involving many specialized fields. Many researches had been done for determining the relationship between hazard occurring and the control measures which to overcome the hazards. Other than that, occupational health and safety are more likely focus on the social, mental, and physical of surrounding. Nowadays, most of the companies’ workers are lack of safety and health practice which are causes them exposed on dangerous surrounding. In this study, the main objective is to observe the occupational safety and health (OSHA) practise at Koko Minda Food Industries (M) Sdn. Bhd. This study is expected to identify the problem that causes the possible accident and it is prevention in order to reduce the possibility of accident during working. By using Preliminary Hazard Analysis (PHA) and HIRARC form, and interview session of several workers, the data being collected and used as the methodology. From the result and findings, the hazards and control measures are identified so that can able to do some improvement in reducing the accidents and risk while working. Moreover, effective job safety and health training are helping in reducing the risk of accidents while working.

Biodiesel economics revolves around both private and public features. Success for an incentive for producers and consumers needs to be sufficient to take part in the marketing arena with the currently accessible alternatives in the private dimension. “Whereas in the civic aspect, success is described in terms of the community objectives that prompt government’s intercession (i. e. subsidies) and whether biodiesel will attain the public goals in a remunerative manner compared to other alternatives if the public assessment is highly preferred, but the market incentives are deficient, there will not be a possibility to produce the biodiesel. On the other hand, if market values generate strong dividends among producers and purchaser, but the social gains are very small, or the costs are extremely high compared to other alternatives, then the activity may not represent a better use of scarce public resources. Biodiesel has become more enticing to the world recently due to its environmental benefits and the fact that it is made from renewable resources. The production cost of biodiesel is the main barrier to commercialization of the product. In the absence of tax relief, there is an urgent need to explore alternative feedstocks for the production of biodiesel. Furthermore, Properties impact of biodiesel and its feedstock, Engine type and its operating conditions Additives are effected by the biodiesel type and production characteristics. Where Engine power is always affected by properties of biodiesel, especially in heating value, viscosity, and lubricity.

The Occupational Safety and Health (OSH)’s field has become a topic for the last 30 years. The establishment of the Occupational Safety and Health Administration (OSHA) reflected the recognition that safety in the workplace is a basic expectation for all work staffs. This study describes the needs of universities in relation to planning the provision of occupational health services, by detailing their occupational hazards and risks and other relevant factors in its laboratories. The purpose of this study is to focus on the hazards, OSH practices and injury management in the laboratories in University Tun Hussein Onn Malaysia (UTHM) in Educational Hub Pagoh (Edu Hub Pagoh). This paper is the initial studies to identify the main causes and steps to overcome the hazards that occurred. The purpose was achieved by visiting the university’s laboratories in order to get the real picture of the hazards in that place. The data collection was carried out through site investigation using Hazard Identification, Risk Assessment and Risk Control (HIRARC) and interview with the staffs and students in the university. This study analysed the HIRARC, and suggest recommendations for improving OSH act in the university’s laboratories. These approaches showed that the university sector is large, with a notably wide range of occupational hazards, and other significant factors which must be considered in planning occupational health provision for individual universities or for the sector as a whole.

Evaporative cooling mist spray is a cost effective solution for many cooling applications. Selection of misting spray nozzle play a major role in order to provide the suitable spraying condition in regards to the application. One of the most widely use mist spray application is evaporative cooling of outdoor open area. This study was carried out to characterized the spray formation, size of droplet, velocity of the droplet and the angle of the spray formation from a commercial mist spray nozzle namely 1/8 SF-CE SM nozzle with 1 mm and 2 mm diameter hole. Water was supplied with different pressure of 1, 2 and 4 bar. High speed video camera and still digital camera using short burst of flash were used to produce the video and image for analysis. The results show that increase in water pressure affect the spray angle, increase droplet speed and decrease droplet size of the mist spray.

Direct imaging technique is always used to obtain correlation of flame height or any other parameter of the visible portions of the flame. This is one of the important methods used in the combustion community to determine the characteristic of flame. Recently, the imaging technique has been developed and enhanced to provide more accurate data. However the utilization of the technology, such as the used of laserbased technique and acquiring sensor, increased the complexity of the process and also increased the amount of cost practically. This paper presents the results of an acoustic excitation towards a Liquid petroleum gaseous flame by using the direct visualizing technique. The direct visualizing technique is used to acquire the flame image and the images will be analyzed by using image analysis software. Results show the flame length at the flame core decreases when the amount of acoustic gradually increases. The effect of excitation towards the flame core is being investigated due to its significant influence toward the overall flame characteristic.

The present paper, focuses on wire electric dis-charge machine of titanium alloys. It can be considered as an attempt to develop two models of response variables, they are; the operating rate, the surface-roughness, and the rate of material removing, In the wire electric dis-charge machine process using the response surface methodology. The pilot plan is based on Minitab 18, and the analysis convey the major six parameters. ANOVA was applied to determine the importance of the advanced model, the test results confirm the validity and suitability of the advanced RSM-model. Lastly, the optimum parameter settings is improved.

The rheological complexities of non-Newtonian fluids can lead to a variety of difficulties including most importantly changes in viscosity during packaging process. In order to give more understanding in this phenomena, the effect of temperature to the viscosity of chili sauce during packaging is investigated. This paper also presents the influence of three different shape of nozzles to the chili sauce flow behavior during filling time. A transient simulation has been conduct in this work using computational fluid dynamics (CFD) ANSYS CFX 15.0. It was found that viscosity is inversely proportional with temperature drop and time. The filling time also improved when using bigger conical angle of the nozzle. The results indicate the increased in production of the chilli sauce and improve packaging process.

The rheological complexities of non-Newtonian fluids can lead to a variety of difficulties including most importantly changes in viscosity during packaging process. In order to give more understanding in this phenomena, the effect of temperature to the viscosity of chili sauce during packaging is investigated. This paper also presents the influence of three different shape of nozzles to the chili sauce flow behavior during filling time. A transient simulation has been conducted in this work using computational fluid dynamics (CFD) ANSYS CFX 15.0. It was found that viscosity is inversely proportional with temperature drop and time. The filling time also improved when using bigger conical angle of the nozzle. The results indicate the increased in production of the chili sauce and improve packaging process.

Renewable energy resources play an essential role in the sustainable energy development as they are friendly energy resources. Solar energy is one of the renewable energy sources are used in many fields from domestic/industrial fluid heating, cooking and electricity production. The parabolic trough collector (PTC) is adopted to be the good choice for medium temperature (150-400 °C) heat necessities. The admiration of solar PTC has generated utility in maximum efficiency energy potential. The heat transfer element (HTE) receiver portion of PTC is the main part in PTC assembly manufactured as tubular shape either without glass envelope or covered with a glass envelope to reduce the radiative and convective heat losses. This article focused on the main parameters was considered in the HTE receiver design of parabolic trough solar collectors (PTC) which were enhanced the heat transfer process in deep details. Further, this work extended to discuss the primary results that came from a different design of PTC receiver based on previous studies in order to benefits researchers who are interested in solar energy collectors. © 2006-2018 Asian Research Publishing Network (ARPN).