SI Engine Research Articles

Multiple Injection Strategies with High Water Injection Rates for Enhancing Performance and Emissions in a Boosted Si Engine

Multiple Injection Strategies with High Water Injection Rates for Enhancing Performance and Emissions in a Boosted Si Engine

The Use of Bioethanol-Isooctane Blend and the Effect of its Molecular Properties on Si Engine Performance and Exhaust Emissions

The Use of Bioethanol-Isooctane Blend and the Effect of its Molecular Properties on Si Engine Performance and Exhaust Emissions

Control-oriented observer for cylinder pressure estimation of SI engine using frequency response function

Control-oriented observer for cylinder pressure estimation of SI engine using frequency response function

Impact of ETBE proportions on RCCI engine to analyse performance and emission characteristics

All over the place the usage of fossil fuels especially gasoline engines emit hazardous pollutants and contributes to global warming. CI engines aim to give convinced benefits compared to SI engines, such as performance improvement and reliable particulate matters interns of CO, HC limitations, such as significant smoke and NOx emissions. To lower the smoke and NOx emissions a new type of IC engines like RCCI is one of the best affordable alternatives. The current research was aimed to determine the particulate matters and outcomes of RCCI engine. In the experimental work diesel as a base fuel and ETBE considered as a substitute fuel with various compositions starting from 0, 10,20 and 30% were used. To safeguard the environment, the findings from this research show a reduction in energy consumption and a reduction in smoke emissions.

Numerical comparative analysis on performance and emission characteristics of methanol/hydrogen, ethanol/hydrogen and butanol/hydrogen blends fuels under lean burn conditions in SI engine

Hydrogen is currently recognized as a clean and renewable energy source, and it has broad prospects for being used in engines. Based on the author’s previous research experience on alcohol-gasoline, and previous researchers’ individual research basis on methanol-H2, ethanol-H2, or n-butanol-H2. An alcohol-H2 engine model is established through the GT-Power simulation platform, and the combustion and emission performance of methanol, ethanol and n-butanol under different hydrogen ratios are compared and analyzed. The results show that adding 10% hydrogen to methanol, ethanol or n-butanol can increase brake torque (BT) to 3.49%, 5.02% and 6.48% at 1500 r/min, respectively. At 2000 r/min, BT increased by 3.14%, 4.74%, and 6.62% respectively. At the same time, brake specific fuel consumption (BSFC) is reduced by 31.51%, 24.6% and 21.16% at 1500 r/min, respectively. At 2000 r/min, the BSFC is reduced by 31.37%, 24.4% and 21.23% respectively. HC, CO and CO2 emissions are reduced, but NOx emissions increase. At 10% hydrogen ratio, compared with ethanol-H2 and n-butanol-H2 blends, methanol-H2 blends can reduce CO by 48.28% and 65.91%, and CO2 by 14.9% and 24.61% at 2000r/min, respectively. When using a high proportion of hydrogen, it can better increase BT and reduce BSFC and carbon emissions.

Experimental Investigations on the Effects of HHO Gas Fuel Additive on Performance of a Gasoline Engine

The hydrogen hydroxyl (HHO) gas as a fuel additive in gasoline for SI engines has a positive impact on improving the performance and reducing the consequences of the burning of fossil fuels alone which are continuously depleting and causing severe problems to the environment. In this paper, the effect of injecting HHO gas additive in the gasoline fuel of a petrol engine was experimentally explored in detail to improve the overall efficiency in terms of performance indicators such as engine fuel consumption, brake horsepower and engine’s torque developed. The engine was coupled with an electric generator to be used for the production of electricity at a relatively low cost. An experimental setup was established to measure the performance indicators and it consists of an HHO gas generator integrated with solar panels, a gasoline engine coupled with an electricity generator, a storage battery, and relevant measuring instruments. The HHO gas was produced and injected into the intake manifold of the engine whilst it was running at different load conditions. The main parameters such as engine RPM, output voltage/amperes of the electric generator were measured and performance indicators were calculated to determine the overall efficiency of the system. From the results, it was shown that the HHO additive had increased performance of the petrol engine performance at a lower HHO-fuel ratio while the engine is running at lean fuel conditions.

Performance and emission study of low HCNG fuel blend in SI engine with fixed ignition timing

Performance and emission study of low HCNG fuel blend in SI engine with fixed ignition timing

Modelling an Electrically Turbocharged Engine and Predicting the Performance Under Steady-State Engine

This paper discusses the evaluation of the energy recovery potential of turboshaft separated (decoupled) electric turbocharger and its boosting capability in a spark-ignition engine through simulation-based work and comparing it to a conventional turbocharged engine in terms of fuel consumption. The main objective of this study is to evaluate the amount of energy that can be recovered over a steady state full-load operating conditions and boosting capabilities from a decoupled electric turbocharger of an SI engine using a 1-D engine simulation software. The electric turbocharged system includes two motors and a battery pack to store the recovered electrical energy. Gt-Power engine simulation software was used to model both engines and utilizes each of the components described earlier. The conventional turbocharged engine is first simulated to obtain its performance characteristics. An electric turbocharger is then modelled by separating the turbine from the compressor. The turbine is connected to the generator and battery, whereas the compressor is connected to the motor. This electrically turbocharged engine was modelled at full load and controlled to produce the same brake power (kW) and brake torque (Nm) properties as the similarly sized conventional turbocharged engine. This step was necessary to investigate the effect an electrical turbocharger without a wastegate has on the engine’s BSFC and determine the energy that can be recovered by the electrical boosting components, and cycle-averaged fuel consumption was evaluated. The evaluation of energy recovered from the electrically turbocharged engine from the analysis can assessed in full-load steady state conditions that can be useful for research in part-load and transient studies involving the decoupled electrical turbocharger. The study revealed that a maximum of 21.6 kW of electrical power can be recovered from the decoupled electrical turbocharger system, whereas 2.6% increase in fuel consumption can be observed at 5000 rpm engine speed.

Tests of a SI engine powered by gaseous fuels blends of LPG + DME of various proportions with variable load

The article presents the test stand and the test results of a vehicle with an SI engine, fueled by a blends of LPG and DME gaseous fuels. During the tests, a chassis dynamometer was used, which reproducibly reflected road conditions. The tests were carried out for various shares of DME in the mixture, thus determining the maximum possible share of this fuel. The measuring points have been extended with different engine loads and different rotational speeds. The analysis of the pressure inside the engine cylinder made it possible to compare the operation of the engine powered by mixtures of different proportions to the reference fuel - LPG.

Experimental study on combustion and emission of an SI engine with ethanol /gasoline combined injection and EGR

Ethanol is a widely used alternative fuel for sustainable development, showing potential for improving the combustion and emission characteristics. Both EGR and lean burn are important technical approaches for engines to reduce emissions In this paper, the performance EDI + GPI four-cylinder spark ignition engine at three access air ratios, five ethanol direct injection ratios and five exhaust recirculation ratios was studied at the speed of 1500rmp. The results show that, the cooperation of EDI and EGR can improve the engine performance. Under lean burn conditions, When 6%EGR+45%EDIr, CA 0-10 decreases 49. 8%. When 12%EGR+30%EDIr, BMEP increases 6. 59%, HC decreases 28.33%, total particle number decreases 93.87%. When 6%EGR+30%EDIr, Pmax increases 26.58%, crank angle corresponding to Pmax decreases 41.98%. And in this condition, CoVIMEP is only 1.46%, decreased 21.51% from the original engine. With the increase of λ, EGR limit of CO moves from 12% to 6%; the optimal ethanol direct injection ratio of CO moves from 30% to 15%. NOx decreases about 136.08 ppm with an average increase of 1% EGR. In summary, ethanol has a higher oxygen content and laminar flame speed is faster. EGR can not only reduce pumping losses and throttling losses, but also effectively accelerate the positive effects of ethanol on combustion and emissions. EGR + EDI + GPI can obviously increase the engine power performance, improve fuel economy and decline the emissions. When the engine speed = 1500 rpm, 12%EGR+30%EDIr is the optimal combination of SI engine at λ = 1.2.

Engine Performances of Lean Iso-Octane Mixtures in a Glow Plug Heated Sub-Chamber SI Engine

Due to the difficulty to directly study ammonia, the present work investigated the engine performance of lean iso-octane/air mixture to approximate ammonia combustion behaviour. The study was conducted using a single cylinder modified diesel engine that features a spark plug and glow plug in the sub-chamber. The investigations varied the engine speeds (1000 and 1500 RPM), glow plug voltages (6 and 10 volts), excess air ratios (1.4 to 1.8), and ignition timings (-2 to -5 °BTDC). The results suggested improved engine performances with a lower excess ratio and higher glow plug voltage due to more complete and stable combustion. By increasing the engine speed, the lean burn limit was extended and improved the engine performances. Because of the sub-chamber feature, delaying the ignition timing improved the engine performances. A larger excess air ratio was found to increase the sensitivity of the engine performances with the ignition timing. The brake mean effective pressure for all conditions has a coefficient of variation of less than 7%, indicating stable combustion. The results suggested that the current setup can be used to investigate ammonia blended fuel and direct ammonia combustion in future works.

An experimental assessment of combustion and performance characteristics of a spark ignition engine fueled with co-fermentation biogas and gasoline dual fuel

Natural gas, biogas and alcohols are alternative fuels for spark ignition engines which can be used for reducing exhaust emissions and improving performance metrics. At the first stage of the study, a pilot scale biogas system was built, and biogas was produced from a mixture of manure and water called slurry, consisting of 40% cattle manure, 35% water, 17% whey and 8% poultry manure by co-fermentation method. Scrubbing and desulfurization were applied to remove the harmful gasses (CO2, H2S) from the produced biogas in two stages. In the end of the purification process, biogas with a CH4 content of 51%, 57% and 87% was produced. In the second stage, these biogas fuels were used in an SI engine, and their impacts on performance and combustion characteristics were investigated experimentally. A 4-cylinder, 4-stroke, water cooled SI engine with an 11:1 compression ratio was used in the experiments. Tests were conducted at various loads and constant speed. Results showed that daily amount of mean biogas production has reached 1.6 m3/day and biogas methane content has reached 72%. In engine tests, as the methane ratio in biogas increases, cylinder pressure and exhaust temperature values increase and brake specific fuel consumption decreases.

Experimental study of knock combustion and direct injection on knock suppression in a high compression ratio methanol engine

Methanol is a competitive low-carbon fuel for spark ignition engines. Though it has higher knock resistance than gasoline fuel, knocking combustion is still an obstacle for the application of methanol in spark ignition engines with relatively higher compression ratios. In this work, experimental investigations into knocking combustion and suppression were conducted on a single-cylinder, naturally aspirated, SI engine with a compression ratio of 15. Firstly, the knocking characteristics of the methanol engine with stoichiometric mixture under port fuel injection mode were evaluated. Results showed that knocking combustion occurred under medium and high loads. Especially, under the condition of indicated mean effective pressure (IMEP) = 0.7 MPa, some random heavy knock cycles with ultra-high knock intensity were observed. The frequency of heavy knock was 2.5% and the highest maximum amplitude of pressure oscillations reached 2.39 MPa. This heavy knock was similar to the super-knock phenomenon in boosted direct injection gasoline engines, and it can not be eliminated by retarding spark timing or adopting fuel-lean combustion. Then, the mechanism of the heavy knock was studied by thermodynamic condition analysis. Results showed that the heavy knock was triggered by pre-ignition which was induced by some hot spots in the combustion chamber. Finally, to make the best use of the charge cooling effect, the methanol direct injection strategy was applied to suppress the knocking combustion. When the engine worked with full opening throttle and adopt a single injection, the maximum knock intensity decreased to 0.43 MPa×°CA at −350 °CA ATDC start of injection which was 5.1% of the maximum value during port fuel injection mode. With the co-optimization of the start of injection and spark timing, the engine with a stoichiometric mixture could operate within the knock intensity limit at full load. Under this operating condition, the crank angle of 50% mass fraction burned located at 12 °CA ATDC and IMEP = 1.05 MPa was achieved. What’s more, adopting the optimal split injection instead of a single injection, the knock intensity was further reduced by 14.3% with a slight reduction of 0.02 MPa in IMEP.

Numerical Study on the Performance and NOx Emission Characteristics of an 800cc MPI Turbocharged SI Engine

The main purpose of this study is to optimize engine performance and emission characteristics of off-road engines with retarded spark timing compared to MBT by repurposing the existing passenger engine. This study uses a one-dimensional (1D)-simulation to develop a non-road gasoline MPI turbo engine. The SI turbulent flame model of the GT-suite, an operational performance predictable program, presents turbocharger matching and optimal operation design points. To optimize the engine performance, the SI turbulent model uses three operation parameters: spark timing, intake valve overlap, and boost pressure. Spark timing determines the initial state of combustion and thermal efficiency, and is the main variable of the engine. The maximum brake torque (MBT) point can be identified for spark timing, and abnormal combustion phenomena, such as knocking, can be identified. Spark timing is related to engine performance, and emissions of exhaust pollutants are predictable. If the spark timing is set to variables, the engine performance and emissions can be confirmed and predicted. The intake valve overlap can predict the performance and exhaust gas by controlling the airflow and combustion chamber flow, and can control the performance of the engine by controlling the flow in the cylinder. In addition, a criterion can be set to consider the optimum operating point of the non-road vehicle while investigating the performance and exhaust gas emissions accompanying changes in boost pressure With these parameters, the design of experiment (DoE) of the 1D-simulation is performed, and the driving performance and knocking phenomenon for each RPM are predicted during the wide open throttle (WOT) of the gasoline MPI Turbo SI engine. The multi-objective Pareto technique is also used to optimize engine performance and exhaust gas emissions, and to present optimized design points for the target engine, the downsized gasoline MPI Turbo SI engine. The results of the Pareto optimal solution showed a maximum torque increase of 12.78% and a NOx decrease of 54.31%.

Effects of differential pressure measurement characteristics on high pressure-EGR estimation error in SI-engines

With proper control, exhaust gas recirculation (EGR) can be used for knock mitigation in SI engines, enabling fuel economy improvements through more optimal combustion phasing and lower fuel-enrichment at high loads. Due to significant pressure pulsations across the EGR valve, estimating the mass flow rates at transient and reversing flows across the valve can be challenging. Many systems utilize the pressure drop across a restriction in a flow path as an indication of mass flow. In automotive applications, the measurement of the pressure drop is accomplished by the use of a delta pressure sensor and the pressure drop mechanism could be a sharp edge orifice or other restrictions such as a valve opening. This technique works well for steady-state flow; however, if pressure fluctuations exist, especially at higher frequencies, this method of measuring mass flow can have large errors. The accuracy of EGR mass flow estimation based on a pressure differential (Δ P) measurement and the steady compressible flow orifice equation is investigated for various Δ P sensor frequencies and sampling rates on Ford 3.5L V6 GTDI and 2.3L I4 GTDI engines. This paper identifies the two major contributors of the error are the long length of the gauge lines and the close location of the downstream tap. The long length of the gauge line results in resonances at low frequency which affects the sensor performance. When the downstream tap is placed too close to the orifice, the accuracy of sensor reading is reduced. The proposed solution suggests keeping the gauge line as short as possible and the downstream tap at least two diameters away from the orifice and using a high-speed sensor. The result from engine testing shows a great improvement in the measurement accuracy by 43%. It is demonstrated that using a slow responding sensor with a low sample rate leads to erroneous mass flow calculation when significant pressure pulsations exist. A minimum of 1 kHz sample rate is needed to increase the accuracy of the EGR estimate within ±1%.

Direct water injection and combustion time in SI engines

Over time, internal combustion engines were profoundly developed becoming more reliable, more economical and less polluting. Even if the current trend is headed towards hybrid and electric vehicles, the development of these engines continues by optimizing its operation with alternative fuels and innovative technologies. Water injection in internal combustion engines is one important way towards engine optimization. This study aims to experimentally determine the effects of direct water injection on the combustion duration of spark-ignition engines. As the thermal processes in internal combustion engines are very complex, the shape of the combustion chamber and other factors, such as the direct water injection timing has a direct influence on the results. This paper explores the potential for such a system in terms of combustion duration showing that the water injection can be beneficial. The concept was applied to a side-valve engine, as this design has a broader potential for injector location and aim.

DÜŞÜK ÇEVRE SICAKLIĞINDA E10 VE M10 YAKITLI BUJİ İLE ATEŞLEMELİ BİR MOTORDA EGZOZ EMİSYONLARININ DEĞİŞİMİ

Biomass fuels are important alternatives to conventional energy sources such as petroleum-based fuels. Biomass fuels especially alcohols have been used in passenger cars. Alcohol blends with gasoline constitute a general use. Particularly, modification of the engine is not required when using at low rates, like gasohol. Gasohol consists of a mixture of gasoline and especially ethanol, and it contains generally 10 percent alcohol. This study deals with the effect of the usage of low alcohol containing (10% ethanol or 10% methanol) blends on the exhaust emissions caused by an SI engine in the 600 seconds of the engine’s operating period from the cold start-up. According to the experimental results, the leaning effect of alcohol on the emissions is clearer in the initial 150 seconds of the experiments. The engine-out CO emissions decreased on average 34.5% for E10 fuel and 44.8% for M10 fuel compared to unleaded gasoline. Also, in the first 150 seconds, an average reduction of 23.2% E10 fuel and 25% M10 was observed in HC. When it comes to the engine-out NO, there were no significant differences by fuel type. Besides, in the study, the tailpipe emissions and converter efficiency were examined by heating the catalytic converter without changing other experimental conditions. Emissions were significantly reduced in all fuels, while efficiency reached 100%, especially for CO emissions.

Effect of variable compression ratio and equivalence ratio on performance, combustion and emission of hydrogen port injection SI engine

The present study includes an experimental investigation of the performance, combustion, and emission parameters of a hydrogen port fueled SI engine under wide-open throttle. The compression ratio (CR) is varied from 10 to 15, equivalence ratio (φ) from 0.4 to 1.0, and speed from 1400RPM to 1800RPM. The ignition timing is maintained at 20° before the top dead center. The brake thermal efficiency increases by nearly 10% from CR10 to CR15, and it also increased by 13.7% by changing φ from 0.4 to 0.9. Similarly, BP increases in the same fashion. The combustion enhances with an increase in peak pressure by increasing CR from 10 to 15 and φ from 0.4 to 0.9; however, φ 1.0 exhibits a negative trend. However, the NOX emission increases continuously with CR and φ, and so as the exhaust gas temperature. The carbon-based emissions are negligible, and volumetric efficiency decreases with φ and increases with CR.

Effect of driving resistances on energy demand and exhaust emission in motor vehicles

Among the fundamental factors affecting the emissions of internal combustion engines is the resistance to motion acting on the car. This is an important factor to be taken into account when testing cars in conditions simulated on a chassis dynamometer. The dependence of the driving resistance function on vehicle speed is determined on the basis of various methods, the most frequently used of which is the so-called alternative method specified in procedures for the type approval of motor vehicles with respect to the emission of pollutants in exhaust gases. The values adopted in accordance with the alternative method differ from the actual resistance acting on the car in road conditions. This is one of the reasons why the emission of pollutants and the fuel consumption of an engine in real road conditions differs from the values given by the car manufacturer, including the emission limits specified in the standards. This paper presents an evaluation of the influence of driving resistance on the energy demand and emission of pollutants in the exhaust gases by sample passenger car with SI engine fuelled by petrol and LPG.

Impact assessment of acetylene fueling on the performance, emissions, and combustion of a spark-ignition engine

ABSTRACT Along with industrialization and transportation, the higher living standard is also the main reason for the increase in energy demand. This increasing energy demand motivates researchers to find new alternative fuels that are eco-friendly and sustainable. In this concern, to analyze the performance, emissions, and combustion characteristics of an SI engine fueled by petrol-acetylene under DF mode is the main purpose of this study. For this purpose, a VCR spark ignition engine was used and operated at the engine maximum speed (1800 rpm). The experimental study was carried out at different acetylene gas flow rates and spark timing. In this study, the acetylene gas flow rate was first optimized on a performance basis. Furthermore, the engine was run at an optimized acetylene gas flow rate (100 LPH) to find out the optimum value of spark timing. In further experimentation, it is also found that the BThE to be maximum and emissions were significantly low or comparable at spark timing 20º CA bTDC (at 100 LPH) as compared to other spark timing and baseline case at all loads. The effects of NOx and smoke are not considerable. Hence, it is not covered in this study. The heat release rate and peak cylinder pressure are found to increase with the advancement of spark timing. But knocking was observed at higher spark advance.