SI Engine Research Articles

The electrical conductivity of the flame front, as a characteristic of the rate of heat release and composition of gas fuel in SI engines

The paper considers the possibility of using the electrical conductivity of the flame front as a characteristic of the rate of heat release and composition of gas fuel in a SI engines. Based on the analysis of the experimental data, the dependences of the parameters of the electrical conductivity of the flame front on the rate of heat release are obtained with the variation of the chemical activity of the gas fuel in a SI engines. The influence of the composition of the mixture and the effect of the amount of added hydrogen on the increase in the rate of heat release and, consequently, on the increase in the electrical conductivity of the flame. The obtained dependences will allow to increase the efficiency and reduce the toxicity of the SI engines operation during the regulation of the working process by ionization sensors.

Analysis of Coolant Temperature and Swirl Motion Effects on Cycle to Cycle Combustion Variations in SI Engine Using Regression and Correlation Techniques

Analysis of Coolant Temperature and Swirl Motion Effects on Cycle to Cycle Combustion Variations in SI Engine Using Regression and Correlation Techniques

Control of Exhaust Emissions from an SI Engine with Metallic (Copper) Coating, Fuel Blend and Catalytic Converter

Control of Exhaust Emissions from an SI Engine with Metallic (Copper) Coating, Fuel Blend and Catalytic Converter

Performance analysis (WHP and torque) on SI engine fueled with low-grade bioethanol and oxygenated fuel additive

Utilization of renewable energy in Indonesia is still relatively low compared to the non-renewable energy source of petroleum, coal, and natural gas. The limited amount of the non-renewable energy encourages the development of alternative fuels. Currently, low-grade bioethanol is one of the alternative fuel being developed. Bioethanol has a higher octane number compared to gasoline. Mixing of bioethanol requires a certain comparison, the mixing is intended to increase the octane number of a fuel mixture. The use of low-grade bioethanol (C2H5OH) as a substitute or mixture of fuels has an impact on engine performance. To get a more optimal effect on the fuel mixture, oxygenated cycloheptanol as an additive can be added to the fuel. This study examined the effect of fuel mixture with the addition of oxygenated cycloheptanol to single cylinder SI engine, 150 cc premix type at 100% throttle position. The tests was carried out on E5, E10, E15 and the addition of 0.5% oxygenated cycloheptanol at each fuel mixture with engine speed variation above 4000 rpm. Performance test will be performed with connecting the machine to a dynamometer. This study aims to obtain efficient performance on the engine with the addition of additives, there is an average increase of 9% in horsepower and 6% in torque.

Comparative performance analysis of an SI engine with treated and raw biogas

The study investigates the comparative performance of a single cylinder SI engine operated on treated and raw biogas. The methane content of this gas is utilised as the fuel. The biogas is treated with different methods before fuelling in the engine and hence the performance of the specified engine is compared. The raw biogas is treated for removal of moisture and H2S because H2S is poisonous in nature and moisture lowers the power output and may corrode engine parts. In this work, CaCl2 and silica gel were used separately for the absorption of moisture. Activated carbon and iron chips were used for the elimination of H2S. The results revealed that the increase in efficiency depends on the type of treatment given to raw biogas. Moreover, scrubbing of moisture had a greater impact as compare to the H2S removal. Effect of biogas treatment on engine emissions is also studied.

A Study of the Mechanism Causing Pressure Waves and Knock in an SI Engine under High-Speed and Supercharged Operation

A Study of the Mechanism Causing Pressure Waves and Knock in an SI Engine under High-Speed and Supercharged Operation

Comparative performance analysis of an SI engine with treated and raw biogas

The study investigates the comparative performance of a single cylinder SI engine operated on treated and raw biogas. The methane content of this gas is utilised as the fuel. The biogas is treated with different methods before fuelling in the engine and hence the performance of the specified engine is compared. The raw biogas is treated for removal of moisture and H2S because H2S is poisonous in nature and moisture lowers the power output and may corrode engine parts. In this work, CaCl2 and silica gel were used separately for the absorption of moisture. Activated carbon and iron chips were used for the elimination of H2S. The results revealed that the increase in efficiency depends on the type of treatment given to raw biogas. Moreover, scrubbing of moisture had a greater impact as compare to the H2S removal. Effect of biogas treatment on engine emissions is also studied.

The Influences of Spark Ignition on Combustion Properties at Lean Condition in SI Engine

The Influences of Spark Ignition on Combustion Properties at Lean Condition in SI Engine

Study of Combustion Products Emitted from SI Engine using N-hexane and 1-hexene as Fuel

Study of Combustion Products Emitted from SI Engine using N-hexane and 1-hexene as Fuel

Study of Aromatic Hydrocarbon Emitted from SI Engine using Isooctane and N-heptane as Fuel

Study of Aromatic Hydrocarbon Emitted from SI Engine using Isooctane and N-heptane as Fuel

Control Unit for a Coreless Stator for use with SI Engine Stepping Valve

Engine efficiency could be increased if valve timing could change with engine revolutions per minute. Poppet valves are fitted with strong springs which return them to their rest positions after being pushed down by cam lobes. Overcoming the spring loaded camshaft drive train requires a lot of engine power. Valve lift, lift duration and phase cannot be adapted with cam lobes on the camshaft but electromagnetic actuators or hydraulic/pneumatic phasing mechanisms could achieve change of lift duration and phase change. Stepping valves with flexible valve event software control, move perpendicular to the piston, thus avoiding piston valve collision problem. Engine cranking requiring fuel, spark and valve event can be done electronically without engine turning. The design of a control unit for an axial coreless stator to control the motion of the stepping valve through the Otto cycle positions intake, exhaust and power / compression is presented with successful simulation of the control algorithm. A 3phase, 12V coil prototype stator with 4 coils per phase, connected in series and consuming 3A from a 12V car battery has been prototypically realized. The project aims at essential processes to run the engine as fuel, air, spark all being software controlled, leading to a more efficient, environmentally friendly, reliable and powerful engine.

Acceleration behavior of SI engine by input electricity in start condition

Acceleration behavior of SI engine by input electricity in start condition

Development of Four-Zone Segmented Transitional Model for Reciprocating Internal Combustion Engine Analysis Using Gasoline

A four zone model based on the first law of thermodynamics has been developed for analysis of combustion in an internal combustion engine. The four zones included an unburned zone and two regions of burned zone, (namely burned gas1 and burned gas 2) and unburned burned zone described as a transitory zone which is a mixture of burned and unburned gases. Arbitrary constant for each of burn (CC2) and unburned (CC1) zone leakages in unburned burned zone was evaluated at optimally predetermined values of 0.005 and 0.00025 respectively, while mass fraction burned from burned gas1, x1 and burned gas 2, x2 were also evaluated at predetermined optimal values of 0.6 and 0.4 respectively. The model was used to analyse an SI engine operating with a gasoline fuel. The engine operating conditions were set at engine speed of 2000 rpm, -35bTDC ignition time and burn duration at 60°. The temperature distribution from the arbitrary constants (CC2, CC1, x1 and x2) for the newly developed four zone model was compared to the two zone model and literature experimental temperature value. The obtained indicated mean effective pressure (IMEP), thermal efficiency (η), cylinder pressure and emission characteristics from the developed model and those of two zone analysis were both compared with literature values.

Study of Combustion Products Emitted form SI Engine using Cyclohexane and Toluene as Fuel

Study of Combustion Products Emitted form SI Engine using Cyclohexane and Toluene as Fuel

The Effect of Fuel Composition on Knock in Lean Burn SI Engine

The Effect of Fuel Composition on Knock in Lean Burn SI Engine

Behaviour of lubricating oil droplets in cylinder on abnormal combustion in supercharged SI engine

Behaviour of lubricating oil droplets in cylinder on abnormal combustion in supercharged SI engine

Performance and emissions of si engine with octane boosters

In today’s world we see that the demand for gasoline and cars keep increasing and one problem which is significantly seen is that we either opt for a fuel which provides higher performance or for a fuel which provides lesser emissions. In this study we aim to provide higher performance and lower emissions by combining two chemicals or octane boosters, namely ethanol and toluene with gasoline and find out its performance and emission characteristics when compared with traditional gasoline and ethanol-gasoline blend. In this study we have made four blends which are PP, E10, E10T5 and E20T5 which are tested against two performance parameters which are Specific Fuel Consumption, Brake Thermal Efficiency with respect to brake power and emissions parameter which are Carbon Dioxide, Carbon Monoxide, Oxides of Nitrogen and Hydrocarbon with respect to brake power as well. In each of these performance and emissions parameters, the blends are compared and we find that E20T5 has the highest performance and E10T5 has the lowest emission.

Fuel consumption evaluation of SI engine using start-stop technology

The engine start-stop technology is gaining acceptance as a key technology adopted by manufacturers to improve the fuel economy of passenger cars. This technology shuts the engine off when a vehicle is at a stop. The inherent issue with the implementation of the start-stop technology in hot climates is the requirement for the air-conditioning system to be in constant operation which reduces the duration of engine shut-off during vehicle stops, and consequently, nullifying the benefit of the system. The aim of this study is to evaluate the potential fuel consumption improvements on a spark ignition engine when using the start-stop technology in real conditions of the Malaysian tropical climate, with consideration towards cabin comfort temperature. The result provides useful insight and enables vehicle manufacturers to assess whether such technology is feasible for implementation in tropical climates. A 1.6 litre spark ignition engine was modelled along with an air-conditioning system model using a commercial one-dimensional engine simulation gas dynamic software. A vehicle driving profile of engine speed and engine torque obtained from real driving on Malaysian roads was captured and used as the boundary conditions for the simulation. Iterations of the start-stop strategy were simulated to further explore the possible impacts on fuel consumption. The result of this study showed that the duration of engine shut-off during vehicle stops becomes shorter due to the necessity of the air-conditioning system to operate in maintaining the cabin’s comfort temperature. With the shorter duration of engine shut-off, the fuel consumption improvement stemming from the start-stop technology is reduced from the average of 20.7 % to 11.0 %, therefore, addressing the concerns on the application of the start-stop technology in hot climate countries and the opportunity to further optimise fuel consumption.

Simulation and Empirical Studies of the Commercial SI Engine Performance and Its Emission Levels When Running on a CNG and Hydrogen Blend

This article is a report on a simulation based on Computational Fluid Dynamics (CFD) and an empirical investigation of in-cylinder flow characteristics, In addition, it assesses the performance and emission levels of a commercial-spark ignited engine running on a CNG and Hydrogen blend in different ratios. The main objective was to determine the optimum hydrogen ratio that would yield the best brake torque and release the least polluting gases. The in-cylinder flow velocity and turbulence aspects were investigated during the intake stroke in order to analyze the intake flow behavior. To reach this goal, a 3D CFD code was adopted. For various engine speeds were investigated for gasoline, CNG and hydrogen and CNG blend (HCNG) fueled engines via external mixtures. The variation of brake torque (BT), NOX and CO emissions. A series of tests were conducted on the engine within the speed range of 1000 to 5000 rpm. For this purpose, a commercial Hyundai Sonata S.I engine was modified to operate with a blend of CNG and Hydrogen in different ratios. The experiments attempted to determine the optimum allowable hydrogen ratio with CNG for normal engine operation. The engine performance and the emission levels were also analyzed. At the engine speed of 4200 rpm, the results revealed that beyond a ratio of 50% of the volume of hydrogen added to CNG a backfire phenomenon appeared. Below this ratio (0~40%) of the hydrogen volume, the CNG and Hydrogen blend seemed to be beneficial for the engine performance and for curtailing the emission level. However, at low engine speeds, the NOX concentration increased simultaneously with hydrogen content. In contrast, at high engine speeds, the NOX concentration decreased to its lowest level compared to that reached with gasoline as a running fuel. The concentration levels of HC, CO2, and CO decreased with the increase of hydrogen percentage.

Evaluation of the Predictive Capabilities of a Phenomenological Combustion Model for Natural Gas SI Engine

Abstract The current study evaluates the predictive capabilities of a new phenomenological combustion model, available as a part of the GT-Suite software package. It is comprised of two main sub-models: 0D model of in-cylinder flow and turbulence, and turbulent SI combustion model. The 0D in-cylinder flow model (EngCylFlow) uses a combined K-k-ε kinetic energy cascade approach to predict the evolution of the in-cylinder charge motion and turbulence, where K and k are the mean and turbulent kinetic energies, and ε is the turbulent dissipation rate. The subsequent turbulent combustion model (EngCylCombSITurb) gives the in-cylinder burn rate; based on the calculation of flame speeds and flame kernel development. This phenomenological approach reduces significantly the overall computational effort compared to the 3D-CFD, thus allowing the computation of full engine operating map and the vehicle driving cycles. Model was calibrated using a full map measurement from a turbocharged natural gas SI engine, with swirl intake ports. Sensitivity studies on different calibration methods, and laminar flame speed sub-models were conducted. Validation process for both the calibration and sensitivity studies was concerning the in-cylinder pressure traces and burn rates for several engine operation points achieving good overall results.