Effect of storage temperature and storage duration on biodiesel properties and characteristics

Biodiesel based on vegetable oils offer the advantage being a sustainable and environmentally attractive alternative to conventional petroleum based fuel. Biodiesel is produced from any fat or oil such as soybean oil, through a refinery process called transesterification. The key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. Biodiesel can be used as a pure fuel or blended with petroleum in any percentage but the standard storage and handling procedures used for biodiesel are the main issue due to the biodiesel fuel specifications. In the quest for fulfill the industry specifications standard; the fuel should be stored in a clean, dry and dark environment. In this research, three different storage temperature were study which are; low (0 – 5 °C), ambient, and high (40 – 50 °C). The key parameters that are required to store biodiesel are discussed, and the recent research advances are noted. Five types of biodiesel after storage all the samples for 2016 hours were tested plus with two product of combustion. Images analysis for combustion process was used to image appearances analysis. Under 2016 hours of storage duration, the effect of degradation was happen although the effect is not significance because the changes are still in acceptable ranges

Circle grid fractal plate as a turbulent generator for premixed flame: an overview

This review paper focuses to ascertain a new approach in turbulence generation on the structure of premixed flames and external combustion using a fractal grid pattern. This review paper discusses the relationship between fractal pattern and turbulence flow. Many researchers have explored the fractal pattern as a new concept of turbulence generators, but researchers rarely study fractal turbulence generators on the structure premixed flame. The turbulent flow field characteristics have been studied tand investigated in a premixed combustion application. In terms of turbulence intensity, most researchers used fractal grid that can be tailored so that they can design the characteristic needed in premixed flame. This approach makes it extremely difficult to determine the exact turbulent burning velocity on the velocity fluctuation of the flow. The decision to carry out additional research on the effect circle grid fractal plate as a turbulent generator for premixed flame should depends on the blockage ratio and fractal pattern of the grid. 1

CFD Analysis of Thin Film Lubricated Journal Bearing

AbstractThe three dimensional CFD analysis were investigated regarding the performance characteristics of a thin film lubricated journal bearing. In the existing literature, several numerical analyses had been reported. Most of these analyses used two dimensional Reynolds equations to find the pressure distribution in the lubricant flow by neglecting the pressure variation across the film thickness. Besides that, most researchers only consider laminar flow. In this paper, three turbulent models which are the Standard k-ɛ model, Realizable k-ɛ model and Reynolds Stress Model (RSM) had been used to simulate the characteristics of a plain journal bearing. Three dimensional models had been simulated using ANSYS Fluent software package to accurately predict the performance of the three turbulent models on the journal bearing analysis. Design parameter like static pressure, wall shear stress and dimensionless load carrying capacity were considered and transient analysis was carried out for the analysis with different L/D ratio of 0.25, 0.5, 1.0, 1.5 and 2.0. The results showed that for the cases of thin film lubricated journal bearing, the turbulent models did not give any significant to the simulation results. However for the case of complex geometry, another simulation needs to be conduct to determine an effect of the different turbulent models in the simulation of the lubricant in bearing system

Study on Dynamic Behaviour of Grass Trimmer Using Finite Element Analysis

Nowadays, research on dynamic behavior of structural components is becoming one of the important parts in the design process for any mechanical system. In order to determine the dynamic behavior of a vibrating structure, measurements of the dynamic properties of structure are essential. Free vibration analysis is one of the approaches that apply the finite element method in determining the structure modes of vibration. Each mode is defined by its natural frequency and mode shape. In this paper, the free vibration analysis of grass trimmer was performed using commercial finite element software, such as Ansys®. The importance of determining these vibration characteristics are crucial as grass trimmer is a common machine that exposed to the dynamic and static forces coming from the engine and rotating blade. A long term exposure of grass trimmer's operator may or potentially suffering a risk of hand arm vibration syndrome. The preliminary results of free vibration analysis demonstrated that the grass trimmer experienced a global first bending mode for 1st natural frequency, a global second bending mode for 2nd natural frequency, a local first torsion mode for third natural frequency, and a combination of global and local bending mode for 4th natural frequency. Later, the analyses were further carried out on the modification of the grass trimme

The fractal flow conditioner for orifice plate flow meters

The sensitivity of orifice plate flow meters to the quality of the approaching flow continues to be a cause for concern in flow metering. The distortions caused by pipe fittings such as valves, bends, compressors and other devices located upstream of the orifice plate can lead to non-standard velocity profiles and give errors in measurement. The design of orifice plate meters that are independent of the initial flow conditions of the upstream is a major goal in flow metering. Either using a long straight pipe, or a flow conditioner upstream of an orifice plate, usually achieves this goal. The effect of a fractal flow conditioner for both standard and non-standard flow conditions was obtained in experimental work and also using simulations. The measurement of mass flow rate under different conditions and different Reynolds numbers was used to establish a change in discharge coefficient relative to a standard one. The experimental results using the fractal flow conditioner show that the combination of an orifice plate and a fractal flow conditioner is broadly insensitive to upstream disturbances. The simulation results also show that the device can be used as a part of a flow metering package that will considerably reduce installation lengths. Previous work with orifice plates has shown that a combination of flow conditioner and orifice plate was promising. The results of using a combination of the fractal flow conditioner and orifice plate for non-standard flow conditions including swirling flow and asymmetric flow show that this package can preserve the accuracy of metering up to the level required in the Standards

The Effect of Storage Container and Light Exposure on Biodiesel Characteristics Derived by Crude Palm Oil

Abstract. This study investigated the effect of types of storage container used to store biodiesel blend (B5) under different storage duration and environment. The biodiesel samples were stored in plastic and glass container under indoor condition with exposure to fluorescent light for 12 weeks. These samples were monitored and the properties tests were recorded for weekly basis. The effects of storage conditions on properties of biodiesel, experimental testing on density, viscosity, acid value, water content and flash point were discussed in detail. Analysis of this study showed that different storage duration, condition and container used gave a significant effect toward the changes of water content, acid value and viscosity. Sample stored in a glass container under indoor without being exposed to any form of light condition recorded the best quality while sample stored in a plastic container under outdoor condition had the worst quality. A long period of storage would decrease the quality of biodiesel due to exposure to direct sunlight, oxidization between ambient oxygen and double bond biodiesel, hydrolysis process between the ambient air and methyl ester and condensation within the storage tank

Emissions Characteristics of Small Diesel Engine Fuelled by Waste Cooking Oil

Biodiesel is an alternative, decomposable and biological-processed fuel that has similar characteristics with mineral diesel which can be used directly into diesel engines. However, biodiesel has oxygenated, more density and viscosity compared to mineral diesel. Despite years of improvement attempts, the key issue in using waste cooking oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. Thus, the improvement of emission exhausted from diesel engines fueled by biodiesel derived from waste cooking oil (WCO) is urgently required to meet the future stringent emission regulations. The purpose of this research is to investigate the influences of WCO blended fuel and combustion reliability in small engine on the combustion characteristics and exhaust emissions. The engine speed was varied from 1500-2500 rpm and WCO blending ratio from 5-15 vol% (W5-W15). Increased blends of WCO ratio is found to influences to the combustion process, resulting in decreased the HC emissions and also other exhaust emission element. The improvement of combustion process is expected to be strongly influenced by oxygenated fuel in biodiesel content

Analysis of Mixture Formation and Flame Development in Biodiesel Burner Combustion Using Direct Optical Visualization Technique

Despite years of emission-reduction attempts, biodiesel combustion still have problem of emitting NOx, CO and particulate matter (PM) into the atmosphere. To reduce emissions, the improvements throughout the combustion process have been considered with the enhancement fuel-air mixing. Optical visualization technique is very essential due to its ability to record real time color image of fuel-air premixing and flame development during burning process. The purpose of this study is to determine the relation between mixture formation and flame development of burner combustion using optical visualization technique and image processing technique. Blending of biodiesel ratio was varied from 5 vol% (B5) – 15 vol% (B15). Water content under emulsified biodiesel was varied up to 15 percent, and equivalence ratio from 0.6 to 2.0. The real spray image of emulsified biodiesel and different equivalence ratio were captured by direct photography method together with color digital camera. The images of the spatial distribution of fuel-air mixing and natural flame luminosity will be further analyzed and to obtain information of the flame development in order to understand the influences of fuel-air premixing on combustion process and burning process. Analysis of spray evaporation and observations of combustion process reveal that the mixture formation exhibit influences to the ignition process and flame development