Effects Of Engine Operating Parameters Research Articles

Effect of engine parameters on the mixture distribution, performance and emission characteristics of a gasoline direct injection engine with baffles – A numerical analysis

Baffles inside the combustion chamber of internal combustion (IC) engines improve in-cylinder mixture distribution, performance, and emission characteristics. However, the effect of engine operating parameters on these aspects of the engine with baffles (EWB) remains underexplored. In this study, using computational fluid dynamics (CFD), the effects of fuel injection pressure (FIP), engine speed and load in a spray-guided, gasoline direct injection engine (GDI) are analysed and compared with the conventional engine. For the analysis, injection pressures of 30, 50, 80, and 120 bar; engine speeds of 1000, 2000, and 3000 rev/min.; and overall equivalence ratios of 0.7, 0.9, and 1.2 are considered, keeping the fuel injection timing constant. Results show that, EWB outperforms the conventional engine under various conditions considered. Also, it is found that the performance of EWB at an FIP of 30 bar is comparable to that of the base engine at an FIP of 80 bar. Additionally, the EWB exhibits better thermal efficiency across all the engine speeds and load conditions. Moreover, the HC and CO emissions of the EWB are found to be lower in most engine operating conditions. However, NOx emissions are marginally higher than those of the base engine.

Performance and Emissions Parameters Optimization of Thermal Barrier Coated Engine Tested with Tamanu Blended Diesel Fuel: A Novel Emission Pollution-Preventive Approach

<p>Diesel engines cause major pollutants such as hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). These emissions affect environmental systems and lead to global warming and climatic change effects. These pollutants also affect humans and lead to health problems like lung cancer, breathing problems, and headaches, etc. Hence, some necessary action has to be taken to minimise these pollutants. There are several steps available to control these emissions. The coating of the piston using catalytic material is an effective method and novel approach of reducing emissions in diesel engines with alternate fuel operated diesel engines. The copper-chromium-zirconium alloy (CuCr1Zr) is known for its good thermal conductivity and good catalyst material, and the piston is coated bycopper-chromium-zirconium alloy with 250µm thickness. Tamanu oil was blended with diesel fuel in a 20% (B20) to 40% (B40) ratio and used as an alternate fuel for the coated engine. The results showed a significant reduction in emissions and improvements in performance. In this research, the Taguchi with grey relational analysis (GRA) optimization technique is also used to study the effect of engine operating parameters on the emission level such as load and fuel for copper-chromium-zirconium alloy-coated diesel engine. Based on experimental results found that fuel is the most influential factor for CO and HCexhaust gas emissions reductions for coated type diesel engines.</p>

A study on effect of engine operating parameters on NOx emissions and exhaust temperatures of a heavy-duty diesel engine during idling

Though NOx emissions from on-road heavy duty vehicles (HDVs) have reduced drastically over the past three decades, upcoming North American regulations may call for further reductions. Lowering NOx emissions below current levels is challenging, especially at lower operating loads such as idling and/or colder climates when the exhaust gas temperature is insufficient for high NOx conversion in the HDV’s exhaust after treatment (EAT) system. This paper investigates the impact of various engine operating parameters on the three-way trade-off between NOx emissions, exhaust temperature, and fuel consumption using a single-cylinder, heavy-duty diesel engine outfitted with a conventional EAT system and diesel exhaust fluid (DEF) injection. The engine parameters investigated include exhaust gas recirculation (EGR) ratio, intake pressure, intake temperature, injection pressure, multiple injections, and engine fluid temperatures. In order to simulate cold climate operation, the baseline intake air, coolant, and lubricating oil temperatures are maintained at 10°C, 40°C, and 50°C, respectively. Results show that using a moderate level of EGR has the dual benefit of reducing the engine-out NOx and increasing the intake charge temperature. Increasing the intake or injection pressure does not result in significant benefit in improving the three-way trade-off. However, using double injection with the second injection at the start of the expansion stroke can help reduce NOx emissions and increase exhaust temperature with marginal impact on fuel efficiency. Based on the parametric study, three particular engine operating conditions are chosen for further investigation with the EAT online. At an identical DEF dosing rate, the rates of NOx reduction in the SCR are similar for the three conditions (∼96%), and the lowest tail-pipe NOx observed for this study is 0.032 g/kWh.

A review on morphology, nanostructure, chemical composition, and number concentration of diesel particulate emissions.

Particulate matter (PM) emitted from compression ignition (CI) engines (diesel engines) has a detrimental effect on human health and the environment. The physical and chemical characteristics of PM emitted from CI-engines are influenced by engine operating conditions and fuel properties. The morphology, nanostructure, and chemical composition of PM affect its toxicity and interaction with the environment. From automotive industry perspective, these parameters influence the design of diesel particulate filters. This study presents a review of the physical and chemical characteristics of particulate emissions from the CI-engine. The present study commences with a brief description about the composition of PM emitted from CI-engine and the PMformation mechanism in CI-engine. Later on, the detailed review of PM's physical and chemical characteristics and the effect of engine operating parameters and alternative fuels on the particle number concentration, morphology, nano-structure, and oxidative reactivity of PM is presented. Online and offline methods of diesel particulate characterization and emerging chemical characterization techniques such as X-ray photoelectron spectroscopy and X-ray absorption fine structure (EXAFS) are also discussed briefly. Correlation between physical and chemical properties, and oxidative reactivityof PM is also discussed. It was found that engine operating parameters affect the physical and chemical properties of PM. Use of alternative fuels changes the diesel particulate morphology, nanostructure, and chemical composition which enhances the oxidative reactivity of PM.

Effect of operating parameters on performance and emissions of a diesel engine fueled with ternary blends of palm oil biodiesel/diethyl ether/diesel by Taguchi method

Since operating factors play an important role on engine emissions and performance, it is important to explore the common influence of several operating factors on diesel engine performance and emission parameters. In this paper, it was aimed to investigate the effects of diethyl ether (DEE) ratio, palm oil ratio, injection advance and engine load on diesel engine performance and emission parameters. Test were planned based on Taguchi L27 orthogonal array (OA) that considered DEE ratio, palm oil ratio, injection advance and engine load as factors and brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxides (NOx) and smoke emissions as responses. The effects of engine operating parameters on responses were determined by variance analysis (ANOVA). Considering the outcomes of the study, optimal levels of each factor were assigned from the point of engine performance and emission attributes. The highest signal-to-noise (S/N) ratios of BTE, BSFC and EGT were observed with the low DEE ratios, low injection advance values and average engine load. Overall, the highest S/N ratios achieved for emission responses were obtained with high DEE percentages and 35 CAs. While the highest S/N ratios for CO and smoke were seen with 20% palm oil, the highest S/N ratios were obtained with 0% palm oil for all other responses. These results showed that ANOVA-supported Taguchi design method is an effective tool with the aim of define the effect rates of engine operating parameters.

Exergetic analysis of a spark ignition engine fuelled with ethanol

Abstract Exergetic analysis consists in the evaluation of the exergetic balance on experimental data. When applied to an internal combustion engine, exergetic analysis can identify sources of inefficiency and potentialities for utilizing exergy that would be rejected. To perform this analysis, experimental data were acquired for different operating conditions of a spark-ignition engine by using gasohol and hydrous ethanol as fuels. With these data, an exergetic analysis was carried out by evaluating the effects of engine operating parameters on associated irreversibilities. Afterwards, a comparison between the exergetic analyses of hydrous ethanol and gasohol was presented. Finally, first and second law efficiencies were evaluated as functions of engine speed, engine load and air–fuel ratio. Exergy distributions of hydrous ethanol at different conditions and the accounts of exergy losses during engine operations were also evaluated.

Effect of Diesel Engine Operating Conditions on the Particulate Size, Nanostructure and Oxidation Properties when Using Wasting Cooking Oil Biodiesel

Present work focuses on the effect of engine operating parameters, including the engine speed and engine load (air/fuel ratio), on the particulate nanostructure and oxidative reactivity when the engine is operated with WCO (waste cooking oil) biodiesel. The particulate samples were collected from the diluted exhaust produced by a medium-duty direct injection diesel engine and were used to analyze the physical and chemical properties via using the high-resolution transmission electron microscope (TEM) and the thermogravimetric analysis/differential scanning calorimetry (TGA/DSC). The TEM images reveal that larger primary particles are formed at low engine speed and high engine load. The particles with typical inner core-outer shell structure are common at high engine load due to the sufficiently high in-cylinder gas temperature and pressure. Quantitative analysis of the nanostructures indicates stronger effect in engine load than engine speed and more soot with shorter and more curving graphene layer at lower engine load. Furthermore, the results of TGA infer that the soot oxidative reactivity is closely related to the nanostructure and the effect of engine load at constant engine speed is more pronounced than the effect of engine speed.

Experimental Investigations of Particulate Size and Number Distribution in an Ethanol and Methanol Fueled HCCI Engine

Alcohols (ethanol and methanol) are being widely considered as alternative fuels for automotive applications. At the same time, homogeneous charge compression ignition (HCCI) engine has attracted global attention due to its potential of providing high engine efficiency and ultralow exhaust emissions. Environmental legislation is becoming increasingly stringent, sharply focusing on particulate matter (PM) emissions. Recent emission norms consider limiting PM number concentrations in addition to PM mass. Therefore, present study is conducted to experimentally investigate the effects of engine operating parameters on the PM size–number distribution in a HCCI engine fueled with gasoline, ethanol, and methanol. The experiments were conducted on a modified four-cylinder diesel engine, with one cylinder modified to operate in HCCI mode. Port fuel injection was used for preparing homogeneous charge in the HCCI cylinder. Intake air preheating was used to enable auto-ignition of fuel–air mixture. Engine exhaust particle sizer (EEPS) was used for measuring size–number distribution of soot particles emitted by the HCCI engine cylinder under varying engine operating conditions. Experiments were conducted at 1200 and 2400 rpm by varying intake air temperature and air–fuel ratio for gasoline, ethanol, and methanol. In this paper, the effect of engine operating parameters on PM size–number distribution, count mean diameter (CMD), and total PM numbers is investigated. The experimental data show that the PM number emissions from gasoline, ethanol, and methanol in HCCI cannot be neglected and particle numbers increase for relatively richer mixtures and higher intake air temperatures.

Effect of intake air temperature and air–fuel ratio on particulates in gasoline and n-butanolfueled homogeneous charge compression ignition engine

An experimental study was conducted to investigate the effect of engine operating parameters on exhaust particulate size–number distribution in a homogeneous charge compression ignition engine fueled with gasoline and n-butanol. In this investigation, portfuel injection was done for preparing homogeneous charge, and intake air preheating was used for auto-ignition of the charge. Engine exhaust particle sizer was used for measuring size–number distribution of particulate matter emitted from the homogeneous charge compression ignition engine. Experiments were conducted at different engine speeds by varying intake air temperature and air–fuel ratio of the charge. Effect of engine operating parameters on particulate size–number distribution, size–surface area distribution, and total particulate number concentration was investigated. Most significant particle numbers were in the range of 6–150 nm mobility diameter for all test conditions. n-Butanol showed relatively higher peak number concentration and lower mobility diameter corresponding to the peak concentrations as compared to baseline gasoline. On increasing intake air temperature, mobility diameters corresponding to peak number concentration of particles moved towards lower mobility diameters. Count mean diameter of particles was in the range of 35–80 nm and 20–65 nm for gasoline and n-butanol, respectively, for all test conditions in homogeneous charge compression ignition operating range.

Effects of engine operating parameters on diesel low-temperature combustion with split fuel injection

This paper shows that a split-fuel-injection strategy can achieve robust, near-zero smoke and nitrogen oxide emissions at reduced exhaust gas recirculation levels under low-temperature combustion conditions. The overall objective of the work was to investigate the sensitivity (in terms of the engine emissions and the fuel economy) of a 50:50 (by mass) split-injection strategy to variations in the key engine operating parameters. Experiments were performed at operating conditions corresponding to a gross indicated mean effective pressure of 500 kPa at an engine speed of 1500 r/min in a 0.51 l single-cylinder high-speed direct-injection diesel engine. The paper presents the effects of different relative fuel injection timings at a variable intake oxygen mass fraction (10.5% and 12%) at a constant intake pressure (120 kPa, absolute) on the smoke, total hydrocarbon and carbon monoxide emissions with the split-main-injection strategy. The effects of a variable fuel injection pressure (90 MPa and 110 MPa) on diesel low-temperature combustion with split injection are also reported, as are the effect of an increased intake pressure (150 kPa, absolute). The combined effects of the operating parameters and the fuel injection timing on the smoke, nitrogen oxide, total hydrocarbon and carbon monoxide emissions and the gross indicated specific fuel consumption are described. For selected operating conditions, the cycle-resolved spray and combustion processes are visualized together with the flame temperature measurement using two-colour optical pyrometry to understand the combustion phenomena occurring in the split-injection strategy. The results of the optical studies show that different low-temperature combustion operating conditions producing similarly low levels of ‘engine-out’ smoke emissions have substantially different histories of soot formation and soot oxidation. An increase in the intake oxygen mass fraction reduced the total hydrocarbon emissions and the gross indicated specific fuel consumption at a given intake pressure, while a higher intake pressure reduced them further. Although significant soot formation took place from the second injection event, the majority of the soot was subsequently oxidized because of a slightly higher flame temperature and slightly higher oxygen concentration than in single-injection high-exhaust-gas-recirculation low-temperature combustion. A higher injection pressure did not have any significant effect on the emissions and the gross indicated specific fuel consumption.

Effects of Engine Operating Parameters on Lean Combustion Limit of Hydrogen Enhanced Natural Gas Engine

An experimental study was conducted on a S.I. engine fueled by compressed natural gas and hydrogen blends (HCNG), in order to test different engine operating parameters that affect lean combustion limit (L.C.L) of HCNG engine. Firstly, constant ignition timing and ignition timing under maximum L.C.L (L.L.T) conditions were compared, then L.L.T conditions were adopted in this paper. The results indicated that for each condition, neither over-retarded nor over-advanced ignition timing are advised in order to achieve leaner combustion. L.C.L increases with hydrogen fraction in the blends, and slightly increases with throttle opening, while decreases when the engine speed is raised

Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions

A study on the sources of variability in the measurement of particle size distribution using a two-stage dilution system and an engine exhaust particle sizer was conducted to obtain a comprehensive and repeatable methodology that can be used to measure the particle size distribution of aerosols emitted by a light-duty diesel engine under transient operating conditions. The paper includes three experimental phases: an experimental validation of the measurement method; an evaluation of the influence of sampling factors, such as dilution system pre-conditioning; and a study of the effects of the dilution conditions, such as the dilution ratio and the dilution air temperature. An examination of the type and degree of influence of each studied factor is presented, recommendations for reducing variability are given and critical parameter values are identified to develop a highly reliable measurement methodology that could be applied to further studies on the effect of engine operating parameters on exhaust particle size distributions.

Soot formation in ethanol/gasoline fuel blend diffusion flames

The aim of this paper is to examine how adding ethanol to gasoline affects soot formation. This is currently an important question with respect to particulate emissions from gasoline powered motor vehicles, but in this paper the ethanol impact is examined in co-flow diffusion flames to decouple combustion chemistry from the effects of engine operating parameters. Soot size distributions are measured as a function of height above the burner for E0, E20, E50, and E85 blends. For all fuels, the size distributions evolve from a single nucleation mode low in the flame through a bimodal distribution at mid heights and finally a single accumulation mode. The soot agglomerates in the accumulation mode, exhibit a bipolar charge. The nucleation mode initially includes charged particles, but becomes electrically neutral with increasing height in the flame. Thermodesorber measurements reveal significant hydrocarbon condensation on nucleation mode particles. This is more extensive for E0, E20, and E50 fuels as compared to E85. In other respects as well, the flames fall into two classes: (1) E85 versus (2) E0, E20, and E50. These groups of flames are visibly distinct and exhibit quantitatively different trends in terms of the size and quantity of particulate matter. The E85 flame appears similar to an ethylene diffusion flame, whereas those in the second group are more akin to a benzene flame. The results are discussed with respect to their implications regarding the effects of ethanol blends on PM emissions from gasoline engines.

Parameter Based Combustion Model for Large Prechamber Gas Engines

Challenging requirements for modern large engines regarding power output, fuel consumption, and emissions can only be achieved with carefully adapted combustion systems. With the improvement of simulation methods simulation work is playing a more and more important role for the engine development. Due to their simplicity and short computing time, one-dimensional and zero-dimensional calculation methods are widely applied for the engine cycle simulation and optimization. While the gas dynamic processes in the intake and exhaust systems can already be simulated with sufficient precision, it still represents a considerable difficulty to predict the combustion process exactly. In this contribution, an empirical combustion model for large prechamber gas engines is presented, which was evolved based on measurements on a single cylinder research engine using the design of experiment method. The combustion process in prechamber gas engines is investigated and reproduced successfully by means of a double-vibe function. The mathematical relationship between the engine operating parameters and the parameters of the double-vibe function was determined as a transfer model on the base of comprehensive measurements. The effects of engine operating parameters, e.g., boost pressure, charge temperature, ignition timing, and air/fuel ratio on the combustion process are taken into account in the transfer model. After adding modification functions, the model can be applied to gas engines operated with various gas fuels taking into account the actual air humidity. Comprehensive verifications were conducted on a single-cylinder engine as well as on full-scale engines. With the combination of the combustion model and a gas exchange simulation model the engine performance has been predicted satisfactorily. Due to the simple phenomenological structure of the model, a user-friendly model application and a short computing time is achieved.

An investigation of engine performance parameters and artificial intelligent emission prediction of hydrogen powered car

With the depletion of fossil fuel resources and the potential consequences of climate change due to fossil fuel use, much effort has been put into the search for alternative fuels for transportation. Although there are several potential alternative fuels, which have low impact on the environment, none of these fuels have the ability to be used as the sole “fuel of the future”. One fuel which is likely to become a part of the over all solution to the transportation fuel dilemma is hydrogen. In this paper, The Toyota Corolla four cylinder, 1.8 l engine running on petrol is systematically converted to run on hydrogen. Several ancillary instruments for measuring various engine operating parameters and emissions are fitted to appraise the performance of the hydrogen car. The effect of hydrogen as a fuel compares with gasoline on engine operating parameters and effect of engine operating parameters on emission characteristics is discussed. Based on the experimental setup, a suite of neural network models were tested to accurately predict the effect of major engine operating conditions on the hydrogen car emissions. Predictions were found to be ±4% to the experimental values. This work provided better understanding of the effect of engine process parameters on emissions.

Les glitazones sont-elles toutes identiques ?

Development of an empirical correlation for combustion duration is presented. For this purpose, the effects of variations in compression ratio engine speed, fuel/air equivalence ratio and spark advance on combustion duration have been determined by means of a quasi-dimensional SI engine cycle model previously developed by the authors. Burn durations at several engine operating conditions were calculated from the turbulent combustion model. Variations of combustion duration with each operating parameter obtained from the theoretical results were expressed by second degree polynomial functions. By using these functions, a general empirical correlation for the burn duration has been developed. In this correlation, the effects of engine operating parameters on combustion duration were taken into account. Combustion durations predicted by means of this correlation are in good agreement with those obtained from experimental studies and a detailed combustion model.

Thrust Chamber Dynamics and Propulsive Performance of Single-Tube Pulse Detonation Engines

This pape r deals with the modeling and simulation of the thrust chamber dynamics in an airbreathing pulse detonation engine (PDE). The system under consideration includes a supersonic inlet, an air manifold, a rotary valve, a single -tube combustor , and a convergent -divergent nozzle. The analysis accommodates the full conservation equations in two - dimensional coordinates, along with a calibrated one - progress -variable chemical reaction scheme for a stoichiometric hydrogen/air mixture. The combustion and flow dynamics involved in typical PDE operations are carefully examined. In addition, a flow -path based performance prediction model is established to estimate the theoretical limit of the engine propulsive performance. Various performance loss mechanisms, including refilling process, mismatch of nozzle exit flow conditions with the ambient state, nozzle flow divergence, and internal flow dynamics, are identified and quantified. The internal flow loss, which mainly arises from the shock waves within the chamber, play s a dominant role in degrading the PDE performance. The effects of engine operating parameters and nozzle configurations on the system dynamics are also studied in depth. Results indicate the existence of an optimum operating frequency for achieving a be st performance margin. For a given cycle period and purge time, the performance increases with decreasing valve close -up time in most cases. On the other hand, a larger purge time decreases the specific thrust but increases the specific impulse for a giv en cycle period and valve close -up time. The nozzle throat area affects both the flow expansion process and chamber dynamics, thereby exerting a much more significant influence than the other nozzle geometrical parameters.

Influence of Diesel Engine Combustion Parameters on Primary Soot Particle Diameter

Effects of engine operating parameters and fuel composition on both primary soot particle diameter and particle number size distribution in the exhaust of a direct-injected heavy-duty diesel engine were studied in detail. An electrostatic sampler was developed to deposit particles directly on transmission electron microscopy (TEM) grids. Using TEM, the projected area equivalent diameter of primary soot particles was determined. A scanning mobility particle sizer (SMPS) was used for the measurement of the particle number size distribution. Variations in the main engine operating parameters (fuel injection system, air management, and fuel properties) were made to investigate soot formation and oxidation processes. Primary soot particle diameters determined by TEM measurements ranged from 17.5 to 32.5 nm for the diesel fuel and from 24.1 to 27.2 nm for the water-diesel emulsion fuel depending on the engine settings. For constant fuel energy flow rate, the primary particle size from the water-diesel emulsion fuel was slightly larger than that from the diesel fuel. A reduction in primary soot particle diameter was registered when increasing the fuel injection pressure (IP) or advancing the start of injection (SOI). Larger primary soot particle diameters were measured while the engine was operating with exhaust gas recirculation (EGR). Heat release rate analysis of the combustion process revealed that the primary soot particle diameter decreased when the maximum flame temperature increased for the diesel fuel.

Methodology for measuring exhaust aerosol size distributions from heavy duty diesel engines by means of a scanning mobility particle sizer

A study of the sources of variability in particle size measurements using a dilution minitunnel and a scanning mobility particle sizer (SMPS) has been conducted in order to obtain a comprehensive and repeatable methodology that can be used for measuring the particle size distribution of the exhaust aerosol emitted by a heavy duty diesel engine. The paper includes three experimental phases: an experimental analysis of the SMPS operating parameters' influence; an evaluation of the effect of dilution conditions, such as the dilution ratio and the dilution residence time; and a study of the influence of sampling factors, such as measurement stabilization and the effect of exhaust system pre-conditioning. An examination of the type and degree of influence of each studied factor is presented, recommendations for reducing variability are given and critical parameter values are identified to develop a measurement methodology of low uncertainty that could be applied to a further study concerning the effect of engine operating parameters on the exhaust particle size distribution.

Development of an empirical correlation for combustion durations in spark ignition engines

Development of an empirical correlation for combustion duration is presented. For this purpose, the effects of variations in compression ratio engine speed, fuel/air equivalence ratio and spark advance on combustion duration have been determined by means of a quasi-dimensional SI engine cycle model previously developed by the authors. Burn durations at several engine operating conditions were calculated from the turbulent combustion model. Variations of combustion duration with each operating parameter obtained from the theoretical results were expressed by second degree polynomial functions. By using these functions, a general empirical correlation for the burn duration has been developed. In this correlation, the effects of engine operating parameters on combustion duration were taken into account. Combustion durations predicted by means of this correlation are in good agreement with those obtained from experimental studies and a detailed combustion model.