Variable Engine Speed Research Articles

Evaluation of Energy Conversion and Distribution on the SI-PFI Engine Fueled by A Gasoline-Bioethanol Blend with AFR Variations

This study aims to investigate the engine performance of spark-ignition engines with port fuel injection using E50 fuel, which contains 50% gasoline or pertalite (in Indonesia) and 50% hydrate bioethanol, at air-fuel ratio variations of 10:1, 12:1, and 14:1. The experiments were conducted using a 1-cylinder, 662 cc engine research test with a constant load of 3 kg and engine speed variations of 1500 and 1800 RPM, as well as a compression ratio of 10:1 and standard ignition timing. The engine ran with E50 fuel, and the experimental results were compared with those of E0 for an air-fuel ratio of 14:1. According to the data, the fuel energy of E50 in an AFR of 14:1 is 0.11 kW higher than that of E0, and it increases by 21.6% when the engine speed increases from 1500 to 1800 RPM. The results also indicate that the efficiency of all performance indicators, such as indicative thermal efficiency, brake thermal efficiency, and mechanical efficiency, is maximized when the engine is operated at an AFR of 10:1 for E50 fuel. Additionally, the volumetric efficiency of E50 reaches its maximum when the fuel is burned at an AFR of 14:1, and it increases as the engine speed increases. However, it should be noted that the brake power decreases due to the frictional power of the fuel increase.

Experimentally Investigating the Potential of Iso-Stoichiometric GEM Blends as a Drop-in Replacement for E50 in SI Engines

Background: Research on alternative fuels for internal combustion engines is crucial due to climate change and energy security concerns. Ethanol-blended gasoline has been a popular alternative fuel, but biomass limitations restrict its widespread use. Methanol offers a solution as it can be produced from non-food sources, extending ethanol's availability. Objective: This study explores a ternary fuel blend consisting of gasoline, ethanol, and methanol as an alternative to binary gasoline-ethanol blend. The objective is to investigate if the isostoichiometric ternary blend offers equivalent fuel properties to E50 (Ethanol 50%, Gasoline 50% (v/v)) gasohol while potentially enhancing engine performance, reducing emissions, and improving combustion characteristics. Methods: A single-cylinder, four-stroke, port fuel injection spark ignition engine was used. The engine was tested with three fuels: pure gasoline, E50 blend, and an equivalent iso-stoichiometric GEM blends. Engine tests were conducted at constant load with varying engine speeds. Performance, emission, and combustion parameters were experimentally measured and compared across all fuels. Results: E50 and its equivalent blends improved brake thermal efficiency but increased brake specific fuel consumption compared to gasoline. It significantly reduced unburned hydrocarbon and carbon monoxide emissions but slightly increased nitrogen oxide emissions. Conclusion: Formulated E50 equivalent blends have identical air to fuel ratio, lower heating values as conventional binary E50 gasoline-ethanol blends. The study suggests that iso-stoichiometric GEM blends have the potential to be a viable alternative drop-in fuel for E50 in internal combustion engines. The future advancements in GEM blends, particularly in optimizing ratios, could lead to patentable inventions.

Artificial neural network based forecasting of diesel engine performance and emissions utilizing waste cooking biodiesel

Ecological and environmental problems resulting from fossil fuels are due to the harmful emissions released into the atmosphere. The rising interest in searching for alternative fuels like biodiesel is growing to solve these problems. Waste cooking oil (WCO) is transformed into methyl ester and combined with biodiesel in percentages of 25, 50, 75, and 100%. Research is done on the impacts of methyl ester blends on engine performance and emissions. Compared to diesel, the methyl ester combination showed 25% lower brake power and 24% loss in thermal efficiency at maximum load and 1500 rpm. However, diesel fuel showed 23% lower specific fuel consumption increase than biodiesel. Compared to diesel, methyl ester exhibits 15% lower air-fuel ratio and 4% volumetric efficiency. Biodiesel lowers CO, HC, and smoke concentrations by 12, 44, and 48%, respectively, compared to diesel. Biodiesel emits 23% higher NOx at 1500 rpm and 100% engine load. To predict the emissions and performance of different percentages of biodiesel at engine speed variation, an artificial neural network (ANN) model is presented. ANN modeling minimizes labor, time, and finances and uses nonlinear data. Predictions were produced about the brake output power, specific fuel consumption, thermal efficiency, air-fuel ratio, volumetric efficiency, and emissions of smoke, CO, HC, and NOx as a function of engine speed and blend ratio. All correlation coefficients (r) over 0.99 and R2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$R^{2}$$\\end{document} values were beyond 0.98 for all variables. There were low values of MSE, MAPE, and MSLE with significant predictive ability. WCO’s biodiesel is a viable diesel engine replacement fuel.

Modeling of an Adaptive HHO Gas Controller Based on Fuzzy Logic and Polynomial Function Controls to Improve Engine Torque of Gasoline Engine

Typical hydrogen-hydrogen-oxygen gas (HHO) usage to improve gasoline engine performance refers to the fixed HHO flow rate method, providing 0.25‒0.5 liters/minute of HHO for every 1000 cc engine size. However, the arising hypothesis expresses that the fixed HHO flow rate method does not optimally improve engine torque for various loads. The research objective is to propose an adaptive HHO gas controller that manages the HHO generator to produce an appropriate HHO flow rate for engine operation by adapting to load and engine speed variations. Hence, the engine torque improvement optimally occurs for various loads. The adaptive HHO controller combines fuzzy logic and polynomial function controls involving real-time engine data, such as mass airflow (MAF), air-fuel ratio (AFR), and the commanded AFR from the engine control unit (ECU), whose values vary with load and engine speed. A system simulation based on Matlab-Simulink investigates engine performance improvement due to the controller. The results show that the adaptive HHO flow rate due to the proposed adaptive HHO controller improves engine torque during small, medium, and big-loaded engine operations, respectively, by 1.5%‒4.7%, 6.8%‒26.8%, and 21.1%‒72.8% depending on engine speed 2500 rpm‒4000 rpm) and the commanded AFR (12.6‒15.4). Conversely, under the same condition, the fixed HHO flow rate with 0.75 liters/minute HHO for a 1500 cc engine, used for comparison, improves the engine torque by 0%‒0.6%, 0.3%‒14.2%, and 9.3%‒50.1%, respectively. The data show that the adaptive HHO controller provides better improvement. Moreover, the adaptive HHO controller improves engine thermal efficiency and reduces AFR error against the commanded AFR.

Comparative Analysis of Gasoline and Liquefied Petroleum Gas (LPG) on Motorcycle Engine Performance

This research aims to determine the efficiency of LPG fuel performance compared to gasoline in motorcycle engines. The research method involves a brake dynamometer test with engine speed variations of 2000 rpm, 2200 rpm, and 2500 rpm. Based on the results obtained, the exhaust gas temperature (°C) at an engine speed of 2000 rpm with gasoline is 148°C and 146°C, while with LPG, it is 107°C and 108°C. The fuel consumption rate (cc/min) at 2000 rpm is 15.8 cc/min, 16.2 cc/min with gasoline, and 9.36 cc/min with LPG. At 2200 rpm, the fuel consumption is 16.2 cc/min, 22.8 cc/min with gasoline, and 10.48 cc/min with LPG. At 2500 rpm, it is 20.2 cc/min, 19.4 cc/min with gasoline, and 14.40 cc/min with LPG. In terms of fuel consumption savings, using LPG as a fuel can significantly reduce fuel usage.

Three-dimensional particle image velocimetry experimental study of transient motion characteristics of different scale vortices in gasoline engine

The paper adopted three-dimensional (3D) Particle Image Velocimetry (PIV) combined with high-speed measurement technology to study the transient motion characteristics of tumble flow induced by small and medium-sized vortices on an optical gasoline engine. Meanwhile, the Proper Orthogonal Decomposition (POD) method was introduced to analyze the evolution of transient vortices, revealing the three-dimensional motion principle of vortices with different spatial scales within the cylinder. The results showed that increasing the engine speed can cause boosted in-plane and out-of-plane velocity, especially for the in-plane velocity. However, the average velocity in the plane was higher than that out of the plane with the difference generally within an order of magnitude. The strong intake jet was the main reason for bringing turbulent kinetic energy in the cylinder. The average kinetic energy and turbulent kinetic energy in the cylinder are both significantly improved at high engine speed. From the results of this experiment, it was revealed that there exists isotropic turbulent pulsation characteristics. Overall, the corresponding flow characteristics of different decomposed modes were different. The first mode section had the lowest average velocity ratio, while the other two had the highest. Due to the dissipation of large vortices into small vortices or the shear action between flow layers, new vortices were generated, leading to the intermittent phenomenon of the motion path of the vortex cluster in the target plane. The average vortex size and velocity circularity corresponding to two varied engine speeds presented a downward trend. The average vortex size was smaller at high engine speed, while the vortex intensity was higher. In addition, increasing the engine speed would decrease the vortex scale but increase the vortex strength. This work provided new fundamental insights into analyzing the characteristics of micro-scaled vortices in turbulent flow, as well as the organization of intake in the gasoline engine.

Experimental and numerical study on a SI engine fueled with gasohol and dissociated methanol gas blends at lean conditions

Hydrogen-rich dissociated methanol gas (DMG) and ethanol are both promising alternative fuels for engines. The study investigates the performance of a spark ignition engine using various gasohol-DMG blends under lean conditions, aiming to evaluate the influence of fuel composition, excess air ratio, and operational parameters including engine load and speed. The results demonstrate that the introduction of DMG substantially enhances the engine's fuel economy, combustion efficiency, combustion stability, and the HC and CO emissions. The addition of ethanol has a distinct impact on engine performance, including increased peak cylinder pressure at lower DMG ratios and a subsequent decrease at higher DMG ratios. It also leads to substantial reductions in HC and NOx emissions but shows a non-linear effect on CO emissions with an increasing ethanol blending ratio. An increase in excess air ratio results in simultaneous reductions in peak cylinder pressure, HC, CO, and NOx emissions. Moreover, variations in engine load and speed respectively impact the cylinder's thermal environment and gas flow, consequently influencing combustion and emission characteristics.

Pengaruh Bentuk Permukaan Piston Rata (Flat) Dan Piston Cembung (Dome) Terhadap Performa Dan Emisi Gas Buang Pada Mesin Sport 200cc

The aim of this research is to determine the effect of engine performance (torque and power), as well as exhaust emissions after replacing the piston. Tests were carried out on a 200CC engine with flat piston specifications with a diameter of 65.0 mm and replaced with a convex piston with a diameter of 65.0 mm using pertalite fuel. The research results obtained by replacing the convex piston (dome) caused the volume of the combustion chamber to decrease resulting in increased torque and power. There was an increase in torque of 0.02607 ft-lbs and an increase in power of 41.95384 HP, then the compression ratio increased by 0.5%. In exhaust gas emissions containing CO, HC, O2, CO2 using a gas analyzer with the results of research on flat pistons and dome pistons, it can be seen that emissions from convex pistons (dome) have increased compared to flat pistons. with the highest increase in stationary of 6.17% in CO emission content due to incomplete combustion residue, which means that the type of piston has a significant influence on exhaust gas emissions. Then the exhaust gas emission test results also show an increase in the O2 emission content on the flat piston at RPM 5000 with a value of 4.24% due to the mixture of oxygen and fuel being more perfect, but on the convex piston (dome) there is a significant increase Compared to a flat piston only at RPM 6500 with a value of 4.53% in O2 emission content. The HC and CO2 emissions content shows unstable or changing values. Apart from that, variations in engine speed also affect the exhaust emissions produced.

ANALYSIS OF CUTTING FLUID ON MASS LOSS OF CARBIDE INSERT IN THE MILLING PROCESS

The Machining process is manufacturing in the world industry that is widely used. The coolant in the machining process functions to lower the temperature and lubricate and clean the gram in the cutting process. The application of coolant in the cutting process is to maintain the quality of the workpiece during the cutting process and also serves to improve tool life so that the tool does not wear out easily. This study aims to determine the effect of a chemical-based coolant based on dromus oil and vegetable CPO on tool wear in the face milling process and to determine whether or not the liquid is effective in reducing and slowing down tool wear. In this research, the face milling process used a grey cast iron specimen as the workpiece specimen used and also used a carbide insert chisel cutting tool with the TPKN 22 VC2 type. The research was carried out by varying the engine speed and also the coolant variation, the engine speed variations used were 80, 360 and 720 Rpm. In the process of administering coolant using the method, it is sprayed directly onto the workpiece area which is cut continuously, in the milling process with a response variable that can be in the form of data or tool wear values that have been observed and tested using a microscope test tool, using the weight (mass) method to see the wear value. This research aims to see how effective the use of vegetable- based coolant (CPO) during experiments as a coolant in the machining process aims to ensure that the final value of tool insert wear must be smaller with (CPO) compared to chemical coolant (dromus).

Effects of exhaust gas recirculation on nitrogen oxides, brake torque and efficiency in a hydrogen direct injection spark ignition engine

This study investigated the effects of exhaust gas recirculation (EGR) on emission and efficiency in a hydrogen direct injection spark ignition engine. EGR was supplied as the low-pressure (LP)-EGR system by controlling EGR valve from zero to 18.7% in terms of mass fraction. The result showed that EGR effect on nitrogen oxides (NOx) reduction became enlarged as higher engine speed due to increasing residual gas fraction. Also, under the same excessive air ratio (λ:2.2), EGR addition made NOx reduction from 89.9 to 98.7 % as varying engine speed. As NOx limit was low, the maximum brake torque was also reduced. However, by using appropriate EGR, NOx margin could be converted to increasing brake torque under the same NOx concentration level from 1.9% to 18.2% as varying engine speeds. From this result, to achieve the maximum output when reaching the turbocharger’s limit in a hydrogen engine and effectively reduce nitrogen oxide emissions, it is not only dependent on lean combustion but also effective to incorporate approximately 20% EGR into the operating strategy.

Impact of Engine Speed and Time Variations on Temperature and Friction Coefficient of Brake Pads with Remote Monitoring Test Equipments System

Impact of Engine Speed and Time Variations on Temperature and Friction Coefficient of Brake Pads with Remote Monitoring Test Equipments System

Bambusa tulda: A potential feedstock for bioethanol and its blending effects on the performance of spark ignition engine

Alternatives to conventional fuel sources must be investigated due to strict regulatory requirements and the depletion of fossil fuel supplies. As a result, of better transportation and population growth, the requirement for energy is increasing daily. Bioethanol may be used successfully to replace both gasoline and spark ignition engine diesel. Most nations blend 10% bioethanol with gasoline in automobiles. Several nations, notably India, have announced that they will soon begin blending 20% bioethanol with gasoline. Bambusa Tulda is used as a raw material for the extraction of bioethanol, which is a type of Indian bamboo. This study covers both the ethanol extraction from bamboo and the effects of various mixtures on spark-ignited engine performance. Four separate blends were developed on a volumetric basis at varying engine speeds, and the wide-open throttle was utilized to evaluate the performance and emissions of each mix with a constant compression ratio of 10:1. When bioethanol was enhanced, combustion efficiency, indicated power, engine power, mechanical efficiency, and volumetric efficiency all increased. Hydrocarbon, carbon monoxide, and carbon dioxide emissions decreased, while nitrogen oxide emissions increased. The engine performance of BE 15 was found to be the greatest among all the gasoline blends tested. According to this study, when nitrogen oxide emission control methods are applied, bamboo may be used as a feedstock for the manufacture of second-generation bioethanol. This invention offers a bioethanol production process that is good for environmental sustainability.

Development of Dibble Mechanism for Tractor Operated Two Row Semi – Automatic Vegetable Transplanter

Vegetables play a crucial role in daily human nutrition, and India ranks second in vegetable production globally. Despite this, manual transplantation is prevalent in India, characterized by labor-intensive practices. The study aimed to address this by developing a tractor-operated linear dibble mechanism for tomato and chili seedlings, designed with seedling spacings of 45 and 60 cm. The evaluation for optimal operating conditions included varying engine speeds (700, 800, 900, 1000 rpm), gear positions (L1, L2), and power take-off positions (P1, P2). Among these, L1P1 and L1P2, with seedling spacings of 57.57 cm and 45.20 cm respectively, aligned with the designed spacings, while L2P1 was excluded due to excessive dibble spacing. Evaluation concentrated on 800 and 1000 rpm, with 700 rpm causing jerks. The preference for 1000 rpm was driven by higher field capacity, as exceeding 1000 rpm posed difficulties for workers. Selections were made with a focus on achieving desired dibble spacings while taking into account worker comfort and field capacity.

The dynamic behaviour of ORC-based power units fed by exhaust gases of internal combustion engines in mobile applications

Exhaust gases Waste Heat Recovery (WHR) in Internal Combustion Engines (ICEs) performed through ORC-based Power Units (ORC-bPU) ensures a reduction of fuel consumption and consequently CO2 emissions. Nevertheless, high fluctuations of hot source push the ORC-bPU to work frequently in severe off-design conditions. Hence, a deep knowledge of the unit dynamic behaviour is fundamental to develop control and operating strategies allowing to achieve a successful recovery. Dynamic response assessment of ORC-bPUs has been treated in literature but making mainly reference to theoretical approaches or to variations of input variables without considering the matching to the engine and the necessary constraints which are present in a real mobile application. Moreover, Moving Boundary (MB) models are generally used as theoretical tools to support the dynamic analysis focusing the attention on Heat Recovery Vapor Generator (HRVG) which rules the plant dynamic response. In MB models, boundary conditions at the HRVG exit are mainly fixed by the expander and by the remaining circuit. To date, the attention was focused on the presence as expander of dynamic machines (turbine), deserving an evident lower attention to volumetric expanders nonetheless their higher suitability for low-medium scale ORC applications (few kWs). To fill these knowledge gaps, a novel approach is pursued in the present paper. The dynamic response of an ORC-bPU was experimentally observed for a step change of torque and revolution speed of an ICE directly connected to the recovery unit. The variation of engine operating conditions produced an unsteady variation of the temperature and flow rate of the exhaust gas feeding the unit. The dynamics of the engine and the connecting pipes is considered as well as all the typical constraints of a real situation. Results show HRVG and exhaust pipe ruling the dynamic behaviour of the unit, leading to long time constant and raising time of gas temperature of 150 s and 300 s respectively. These results show that the unit almost always works in transient conditions being engine torque and speed variations very fast. Nevertheless, thanks to the self-regulation capacity and the robustness of the scroll expander, the unit reacts in a satisfactory way. A further novelty of the present study concerns the integration of the widely used Moving Boundary (MB) approach with Permeability theory which considers the presence of a volumetric expander and all the ither downstream components, finding a match not available in literature between the HRVG and a volumetric expander and pump. The results of the new Permeability-Moving Boundary model (P-MB) was compared with those of a more comprehensive mathematical model. The comparisons show a comparable accuracy and a significantly lower computational time achieved with P-MB. Hence, P-MB could be implemented on board to set up control strategies enhancing the recovery tuned by a model-based approach.

Analysis of Exhaust Gas Emission of Motor Vehicles with Variations of Fuel Types

The discrepancy between the use of vehicle fuel types and the vehicle's technical specifications is expected to affect exhaust emissions. This study aims to examine the effect of using four types of fuel with different octane number specifications on two four-wheeled motor vehicles with an EFI fuel delivery system on exhaust gas emission parameters of carbon monoxide (CO), hydrocarbon (HC), carbon dioxide (CO2) and non-emitting gases Oxygen (O2). With a quantitative experimental approach method using the Automotive Emission Analyzer and simple linear regression analysis, the results showed that the use of variations with octane numbers RON 98, RON 92, RON 90, and RON 88 fuels at the same time as variations in engine speed (1000 – 3000) RPM showed an effect on concentration. HC and CO emissions decreased with each increase in the octane number of fuel, RON 92 fuel with the lowest average CO / HC (0.0013% / 0.46 ppm) and RON 98 with the lowest average CO / HC (0.0026% / 0 ppm). The use of RON 92 fuel is more effective and inexpensive to apply to vehicles with an EFI fuel delivery system (with compression of 1:10/10.2) compared to RON 98 fuel which emits higher CO and HC emissions at low engine speed (1000 -1500) RPM.

Throttling effect on the availability and sustainability of a gasoline-fuelled spark ignited multi-cylinder engine

Large energy waste is one of the internal combustion engine challenges, making it unsustainable and unfriendly to the environment. Charging the spark ignition engine with the required fuel-air mixture is associated with a particular quantity of energy loss due to flow throttling. Throttle position effect on the availability, sustainability, and environmental trends of a gasoline, spark-ignited engine was evaluated based on thermodynamic analyses of real experiments. The availability and sustainability analyses were performed utilizing the relations governing the thermodynamic system under various engine speeds (1500–4000 rpm) at part and wide-open throttle (POT and WOT) conditions. The results indicated that the WOT position mostly ensures the best sharing of useful availability, i.e., 2% greater, more sustainable, i.e., 3% better, and environmentally friendly, i.e., 16% healthier, engine operation for the entire tested speed range. On the other hand, an optimum engine speed, mostly 3000 rpm, of the tested engine yielded the maximum efficiencies, i.e., 3% higher, lowest entropy production, i.e., 15% lower, and best availability proportions, as well as the most sustainable and environmentally friendly operation mode. Furthermore, a considerable perspective of the waste heat recovery of the associated availability with exhaust gases was achieved under POT and WOT conditions. The acquired improvement in engine efficiency based on the recovery potential was in the range of 3% to 19.7% and 13.6% to 24% for the WOT and POT conditions, respectively. However, the detected recovery rate and efficiency improvement were randomly tended with engine speed variation. In terms of the recovery potential, the highest engine efficiencies were about 46% and 50% at 3000 rpm, for the POT and WOT conditions, respectively. Finally, in average around 10% and 52% increment with 20% and 24% reduction was detected for the environmental impact of the CO2, NOx, CO and HC, respectively, under the WOT condition in comparison with POT condition.

A comparative study on the effect of nano-additives on performance and emission characteristics of CI engine run on castor biodiesel blended fuel

Biodiesel is a promising alternative fuel because of its renewable status, biodegradability, non-toxicity, and low pollution levels. However, other limitations such as high viscosity, low thermal energy content, poor atomization, greater densities, and higher (NOx) exhaust emissions hinder its adoption as a prospective diesel alternative. The current study focuses on comparing and analyzing the performance and emission effects of introducing single and hybrid cerium oxide (CeO2) and aluminum oxide (Al2O3) nanoparticles to a fuel blend of 20 % castor biodiesel and 80 % diesel (CB20) made from castor seed oil. The pulsed plasma in liquid technique, a straightforward one-step procedure, was used to create cerium oxide (CeO2) nanoparticles. When Al2O3 nanoparticles were added to the CB20, the cylinder pressure and rate of heat release increased. Therefore, in this study single and hybrid cerium oxide (CeO2) and aluminum oxide (Al2O3) nanoparticles are introduced. The tests were conducted on a single cylinder compression ignition engine at varied engine speeds between 1250 and 3200 rpm while keeping a constant engine load. Using a water bath and sonication, two concentrations of the nanoparticles—80 and 100 ppm—were introduced to the fuel blends, along with Tween 80 and span 80 surfactants to improve blend stability. Different tested fuel samples, including pure diesel CB0, CB20, CB20C100, CB20C80, CB20A100, CB20A80, CB20A40C40, and CB20A50C50, were examined for their physiochemical properties, such as density, viscosity, cloud point, pour point, flash point, and fire points, as well as engine performance parameters, including torque, power, fuel consumption, BTE, and EGT. CB20A50C50 and CB20A40C40 both had an average brake power that was higher than diesel fuel by 6.14 % and 1.25 percent, respectively. The average brake-specific fuel consumption decreased by 3.21 % to 8.29 % when using hybrid and single nano-additive blended fuels compared to CB20. CB20A50C50 exhibited a 20.38 % higher brake thermal efficiency than CB20. Notably, CB20C100 showed a 29.52 % reduction in HC and a 38.32 % reduction in CO, while CB20A50C50 demonstrated a 10.24 % decrease in NOx compared to CB20. Overall, the results of this study indicate that the generated fuel blends combining castor biodiesel and aluminum oxide/cerium oxide nanoparticles hold promise as alternate fuels for diesel engines, with positive impacts on engine performance and emissions.

Pengaruh Kecepatan Putar dan Jumlah Masukan Batang Singkong Terhadap Kinerja Mesin Rabakong Tipe TEP-6

Cassava production not only produces tubers, but also produces waste, one of which is cassava stems. So far, the waste of cassava stems has not been widely used by farmers, so that after the cassava is harvested, the cassava stems are just left lying on the ground. This study aims to reduce cassava stem waste through size reduction using a cassava stem chopper (Rabakong) with variations in engine speed per minute (RPM).This research was carried out at the Agricultural Equipment and Machinery Power Laboratory, Department of Agricultural Engineering, Faculty of Agriculture, University of Lampung in May - June 2023. The treatment used 3 variations of RPM namely 800, 1000, and 1400 where each used 3 different amounts of input, and each RPM was repeated 3 times. The number of inputs used is the input of 3 sticks, 4 sticks, and 5 sticks. The results showed that chopping using the RPM setting of 1400 and the input amount of 4 cassava sticks had the best working capacity with a value of 194.448 kg/hour. Lowest fuel consumption by using the RPM setting of 800 and the number of inputs of 3 sticks with a value of 1,073 liters/hour. Keywords: Cassava Stems, Input, Rabakong, RPM.

KINERJA DAN EMISI MESIN DIESEL 1 SILINDER BERBAHAN BAKAR CAMPURAN BIODIESEL NYAMPLUNG DAN ETANOL

Research has been carried out on the effect of biodiesel and ethanol fuel mixtures on diesel engine performance and emissions. Ethanol (C2H5OH) is a type of alcohol that can improve the characteristics of biodiesel. The effect of ethanol on engine performance was investigated by adding B30 (a mixture of 30% nyamplung biodiesel (calophyllum inophyllum) and 70% petrodiesel). The concentration of ethanol added to B30 is 10% v/v which is called the B30E10 mixture. The composition of the fuel mixture is B0 (petrodiesel), B30, B30E10 and Pertadex. The research was conducted on a single cylinder four stroke diesel engine with a natural air system and coupled to a generator that functions as a dynamometer. Three times the test was carried out for each load applied to the engine varying from 0, 200, 400, and 600 W at a constant rotation speed of 1700 rpm. The research results that the constant engine speed method and variations in lamp load produce torque values (Nm) and effective power (kW) which tend to be the same between fuels, this happens because it is influenced by the governor mechanism. The highest fuel consumption occurred at the addition of 10% ethanol (B30E10). The lowest thermal efficiency occurs in B30E10. Exhaust emissions of carbon monoxide decreased with the addition of 10% ethanol.

Influences of various metal oxide-based nanosized particles-added algae biodiesel on engine characteristics

Nano fuel technology is widely used to enhance fuel capability to improve combustion, performance and emission behaviors of the engines. On the other hand, biodiesel is the best alternative to the conventional fossil fuels. However, it may worsen the engine characteristics, and should be modified. In this framework, this investigation aims to improve algae oil biodiesel by employing nano fuel technology by mixing metallic oxide nanoparticles like CeO2, SiO2 and TiO2 with a concentration of 150 mg/lit. The base fuel B25 blends consist of Algae oil-based biodiesel 25 vol% and 75 vol% of diesel. The B25 blends and 150 mg/lit concentration of nanoparticles were preferred through basic experimentation. An ultrasonicator was employed in the preparation of nano fuels such as B25CeO2, B25SiO2, and B25TiO2. The prepared Nano fuels were characterized and tested in a diesel engine at varying engine speeds ranging from 1250 rpm to 2500 rpm with the step of 250 rpm. The results revealed that the use of B25TiO2 recorded the maximum engine cylinder pressure at 72.2 bar was recorded at the 5O crank angle and maximum heat release rate of 63.2 J/OCA. The maximum speed of the engine leads to higher BTE. In comparison to that of conventional diesel fuel, the use of the B25+TiO2 blend increased in-cylinder pressure by 23.4%, heat release rate by 16.6%, BTE by 32.4%, CO2 by 65.09%, and decreased BSFC by 25.62%, CO by 33.4%, NOx by 68.3%, UHC by 22.75%, and smoke opacity by 30.99%. Hence, this investigation found a novel blend of B25TiO2 for lowering emissions and improving diesel engine performance.