Search

Biodiesel predicted to replace diesel fuel in the future that comes from the transesterification process of plant oils, animal fats, or used oils. One of the potential raw materials is nyamplung seeds because they are scattered in Indonesia, easy to cultivate, and bear fruit throughout the year [1]. The purpose of this study was to determine the effect of mixing pure diesel fuel and nyamplung biodiesel with the fuel composition B0, B20, B30, and B100 on the spray tip characteristics penetration, spray angle, and sauter mean diameter.This study focussed on simulation. The simulation method is carried out to predict the distribution and mean diameter of droplet using commercial fluent software. Fuel spray is carried out in free air with an injection pressure of 15 MPa, fuel temperature 28.2 ℃ and free air temperature 30.1 ℃. The spray process was taken at 6.25 ms and then the fuel spray characteristics were measured using the ImageJ application.The results of testing the fuel spray characteristics indicate that the amount of biodiesel content in the fuel is 20-100%. It can increase the length of spray tip penetration about 0.7-4.9%, a decrease in spray angle of 9.2-32.1% and the sauter mean diameter value increased by 20.1-84.6%. It caused by increasing the amount of biodiesel content in the fuel which results in an increase in the value of density, viscosity and surface tension of the fuel.

The research aims to analyze and reveal combustion characteristics in a Cylindrical Meso Scale (CMS) Combustor with a wire mesh flame holder as a reference for designing a compact, efficient, and high-density energy source for future vehicles. This experiment analyzes the combustion ’s of a butane gas (C4H10)-air mixture in a cylindrical meso-scale (CMS) combustor with the addition of wire mesh flame holder on the stability of the combustion flame, as initiation of future vehicle energy source. The diameter of the CMS combustor with wire mesh flame holder is varied to give an idea of the effect of heat loss on the combustion flame's characteristics. The results show that the wire mesh as a flame holder is essential in the combustion stabilization mechanism. A stable flame can be stabilized in a CMS combustor with wire mesh. Variations in the diameter of the CMS combustor will result in variations in the surface-to-volume ratio, heat loss, and contact area of the wire mesh flame holder. At a large diameter, it produces the characteristics of a combustion flame with a more stable flame stability limit than a smaller diameter, a dimmer flame visualization than a smaller diameter at the same air and fuel discharge, a more distributed flame mode map area than the smaller diameter, lower flame temperature and combustor wall temperature than the smaller diameter, and relatively higher energy output than the smaller diameter.

Al-SiC is a composite composed of AA6061 as a matrix and SiC as a reinforcement particle. The variation of mass added will affect the mechanical properties of the composite because Al-SiC is hardenable, which means that its mechanical properties can be improved by adding the reinforcement component. However, an excessive portion of SiC leads to a decrease in mechanical properties. The purpose of this study was to find the optimal composition of the addition of SiC into the aluminium matrix to gain maximum tensile strength and hardness. The mass fraction variation that would be used in this composite was the addition of 6%, 8%, and 10% SiC with the addition of 1% Mg as a wetting agent. The mixing process used the stir casting method. The process of adding SiC and Mg was carried out by melting the aluminium while stirring it for a certain time before it went to the furnace. The ASTM E8/E8M standard was used for observing the tensile strength of the specimens. Machining was carried out before testing. The specimens were also tested for hardness using the Rockwell hardness method. The result shows that the addition of SiC at the amount of 6%, 8%, and 10% SiC increased the ultimate tensile strength by154.10 MPa, 175.01 MPa, and 198.14 MPa, respectively. Similarly, the hardness also increased up to 30.1 HRF, 48.1 HRF, and 66 HRF, respectively. Microstructure observation also confirmed that a 10% SiC fraction results in less defect and good wettability. The addition of 10% SiC and 1% Mg resulted in maximum tensile strength and hardness and the best microstructure.

The burning rate of coconut oil droplets has been investigated experimentally by adding bio-additives of clove oil and eucalyptus oil. Tests were carried out with single droplets suspended on thermocouples at room atmospheric pressure, and room temperature and ignited with a hot wire. The addition of clove oil and eucalyptus oil as bio-additives into coconut oil was 100 ppm and 300 ppm, respectively. The droplet combustion method was chosen to increase the contact area between the air and fuel so that the reactivity of the fuel molecules increases. The results showed that the eugenol compounds contained in clove oil and cineol compounds in eucalyptus oil were both aromatic, and had an unsymmetrical carbon chain geometry structure. Furthermore, this factor can potentially accelerate the occurrence of effective collisions between fuel molecules. Therefore the fuel is combustible, as evidenced by the increased burning rate, where the results show that without bio-additives, the burning rate of crude coconut oil (CCO) is about 0.7 seconds. These results are 0.15 to 0.2 seconds slower than CCO with bio-additive, which is around 0.55 to 0.6 seconds. Moreover, from the observations, it was found that the highest burning rate was achieved in both bio-additives with a concentration of 300 ppm.

Technology of motor vehicles that are environmental friendly and fuel-efficient has been a demands in this era of energy crisis and global warming. The growth in number of motor vehicles which are very rapidly has raised the issue of air pollution that should be immediately resolved. Material utilization of iron (Fe) containing low carbon steel is often called low carbon as material for reducing pollution in this study applies principles of catalysation in motor vehicle exhaust gas pollutants with the material. The purpose of this research is generating a product of an architecture modification exhaust pollutants reducing motor vehicle by applying the technology of catalytic converter to reduce pollutant gases like CO and HC that are contained in the exhaust gas, as well as improving performance of the machine. The methods used to achieve these goals is the experimental method, which starts with design and creating of modification reducing exhaust gas as well as testing the effectiveness for emissions level and testing the poduct against the performance of the machine. The results of this research is the use of modification exhaust with application of catalytic converter technology with low carbon steel filler metals as catalysts in motor gasoline four steps can lower the levels of concentration of exhaust pollutants carbon monoxide (CO) and hydrocarbons (HC), increase torque, power, and lower fuel consumption than a standard exhaust conditions. Testing with a percentage of 75% volume of fibres low carbon steel has the best average results in the reduction of carbonmonoxide (CO) gases of 0.41% (lowered levels of CO 71.79% from the standard exhaust conditions) and hydrocarbons (HC) by 77.89 ppm (lowered levels of HC 61,25%), also can generate an increase in the average torque of 15.46% (with an average value of 4.23 Kg. m), an increase of the average effective power of 19.14% (with an average value of 11.76 HP), and decreasing in fuel consumption of 18.51% (with an average value of 1.48 Kg/hour) of the standard exhaust treatment conditions. Keywords: Catalytic Converter, Low Carbon Steel, Hydrocarbon, Carbonmonoxide

To obtain maximum engine performance one way to do is to do modification the camshaft . Changes can be made to alter or modify the time to open and close the valve. As already unknow that big power generated by the engine is affected by the amount of residual gases that exit the combustion chamber. The amount of air and fuel mixture entering the combustion gases and regulated by the duration of the opening and closing of the valve.For it was necessary to study the extent to which the effect of the change by the duration of the camshaft to the increased power and torque of the engine, which can then be recovered size is definitely the most appropriate duration to generate great power and torque. Effective power produced at 220 ° camshaft duration variation is at 6000 RPM of 7.7 HP, variations in camshaft duration 227 °, ie at 8.49 HP at 6500 RPM, variations in camshaft duration 233 °, ie at 6500 RPM at 8.77 HP, variations in camshaft duration 239 °, ie at 9.53 HP at 6500 RPM. Average turning moment - resulting in maximum average variation of camshaft duration 220 °, ie at 6000 RPM of 1.37 Nm Variations camshaft duration 227 °, ie at 6000 RPM 1.43 Nm Variations camshaft duration 233 °, ie at 1.47 Nm at 6000 RPM Variations camshaft duration 239 °, ie at 6500 RPM of 1.51 Nm Keywords: effect of variations in the duration of the camshaft, power, torque, and fc (fuel concumtion).

Top burner cotton less bioethanol stove is one of the appliances that apply the use of renewable fuels for domestic capacity. Application of this stove burner is a solution for scarcity of fossil fuel supplies. This study focused on variations in the distribution of flame temperature and performance on the top burner as grade of bioethanol varies at value of 55%, 70%, 85%, and 97%. Flame temperature distribution measured at of their hot spots and then simulated using Matlab R2011a to obtain isothermal contour flame shape and determine the flame temperature distribution of the flame. Performance testing used Standard International Water Boiling Test version 4.1.2 to determine the power, thermal efficiency, specific fuel consumption, and heat transfer. Results obtained that the flame temperature distribution, in the form of profiles and contours isothermal flame, reached its optimum when using bioethanol grade of 97%. Optimal performance on a stove burner using bioethanol 97% with power stove equal to 1.85 kW, the thermal efficiency of 72.21%, specific fuel consumption (Sfc) 0.512 kgbb/kguap, and heat transfer at value of 2,959 kW was also achieved at the same grade. The higher grade bioethanol used to increase the flame temperature distribution and performance of the stove. Keywords: Bioethanol, Stove, Temperature Distribution, Performance

To reduce dependence on oil usage that increasing every day, many countries have adopted a substitution of petroleum fuels with renewable fuels such as ethanol is used as a blend in gasoline. Because ethanol can be produced from agricultural products such as corn, sugarcane, rice, etc., then the ethanol is one of the best alternative fuel in motor gasoline. Blending gasoline with ethanol would not fully produce a homogeneous mixture, need for additional treatment to obtain a more homogeneous results, one way is to heat the fuel. If the fuel is heated, there will be expansion or changes in fuel volume, in addition to the viscosity of the fuel will be decreased. It’s can be explained by the theory of thermodynamics, which states that the higher the temperature of a fluid, the fluid molecules will move quickly so at fixed volume will increase the pressure. Fuel with low viscosity will be atomized better, resulting smaller granules. With these conditions the process of mixing fuel with air will be more homogeneous so that the fuel burn more. The results obtained from testing the performance of the engine is the highest maximum torque obtained when using T40˚C fuel, with 6.37 Nm at 3400 rpm, increased 22.5%. The highest maximum power obtained when using T40˚C fuel with 3.450 HP at 5600 rpm, increased 5.11%. lowest Fuel Consumption average obtained at T40˚C fuel with 4.46% more efficient. Keywords: gasoline, ethanol

The air pollution rate caused by the vehicles in big cities is now reach the critical limit. It affects the environmental health as well as the financial factors. To reduce the pollutant gas from the vehicle engines emission, a technology is needed. One of the technology is the application of catalytic converter inside the exhaust emission. A research has been done on 125 cc motorcycle engine to modify its exhaust emission. The catalysts used in this research was made of copper and designed using the honeycomb system with various diameters ( 4, 6, 8, 10, 12 mm). The observation variables are catalyst temperature, CO and HC emission rate. The emission of CO and HC from the sample engine was then compared with the standard emission rates. Result showed that increase of the copper catalyst temperature resulted in decrease of CO and HC emission rates. The decrease started to occur for all the catalysts at 225 oC. Optimum convertion efficiency is up to 47,93 % (CO) and 50,36 % (HC). Both optimum efficiency reached at the temperature of 325 oC using 8 mm diametered catalysts. Keywords : air pollutions, honeycomb system catalytic converter, temperature and copper

Exhaust muffler system is commonly called is one vital part of a motor vehicle. This serves as an exhaust silencer is removed from the machine until at a certain noise level permitted with little possibility of a decline in torque and engine power. This study aims to determine the influence of the exhaust pipe diameter of straight throw gasoline engine performance, pressure, exhaust gas flow rate and intensity of noise generated. From the results of research in getting that throw straight exhaust pipe diameter which was able to improve gasoline engine performance, pressure, flow rate of exhaust gas and noise intensity. This is evident from the results of research that shows that there was an increase by using a exhaust pipe diameters greater straight throw. Keywords: exhaust pipe, exhaust silencer and straight throw