Performance Of Internal Combustion Engines Research Articles

Development of a technology for the manufacturing of parts/components of an internal combustion engine involving additive manufacturing methods

Introduction: the article considers a strategic objective consisting in reduction of the Russian companies’ dependence on highly sought-after imported power engineering equipment, including internal combustion engines used as part of auxiliary power units. In the article, the co-authors propose to integrate additive manufacturing methods into technologies used to produce internal combustion engines, their parts and components, which are temporarily or permanently impossible to import. The co-authors have proven the feasibility of advanced additive technologies in respect of casting molds and castings designated for internal combustion engines. An alloy of cast iron featuring an advanced chemical composition was developed. It enables the use of complex shape castings free from any non-metallic inclusions to produce engine parts and components; these castings demonstrate higher values of strength and wear resistance, they are a must for an internal combustion engine operating in severe conditions. The co-authors demonstrate the casting mold production process using ExOne’s S-MAX 3D printer.Methods: the study is based on the analysis of strengths, weaknesses and peculiarities of established casting methods, with account for faster production cycles and a higher quality of final products.Results and discussion: in the article, the co-authors analyze the proposed technology used to manufacture castings for “a block of cylindersˮ and “a head of the block of cylindersˮ.Conclusion: the newly developed technology for production of parts/assemblies of an internal combustion engine, including an advanced alloy having a new chemical composition, enables manufacturers to make high quality parts/ assemblies for an internal combustion engine in the most economical and productive way.

An intake manifold geometry for enhancement of pressure drop in a diesel engine

Intake manifolds are one of the most important components affecting performance in internal combustion engines. An intake manifold having low pressure drop is very important to maximize the mass of the drawn air into the cylinder. In addition, the intake manifolds ensure that the air is sent in equal amounts to the cylinders in order to obtain stable and compatible piston movements. Therefore, optimizing the geometry of intake manifolds is very important. One of the traditional methods in optimization is to manufacture a prototype having different manifold geometries, to test these manifolds in engine tests and to select the best performance. This method is very expensive both in terms of time and cost. It also does not provide the best possible design with an information about the behavior of the air passing through the manifold. If a designer gets this information, he may know exactly which regions need to be improved. Nowadays, optimization studies supported by computational fluid dynamics (CFD) is used commonly since they cost lower in time and money than conventional methods and give optimum results faster. The influence of the changes in the manifold geometry on the flow and pressure can be investigated in detail by using the CFD method. The best solution can be obtained with a high accuracy by focusing directly on the region where the geometry problem is. Our optimization study has been carried out by using Ansys-Fluent software.

Power Improvement and NOx Reduction Strategies for a Hydrogen-Fueled Multicylinder Internal Combustion Engine

Abstract The conventional operation of a hydrogen internal combustion engine (ICE) under lean conditions results in low NOx emissions, however, at the cost of power generated. In this study, the power output of a hydrogen-fueled ICE was increased while maintaining the NOx emissions at low levels. The power output was increased by turbocharging, relatively richer operation, and spark timing optimization, whereas a combination of exhaust gas recirculation (EGR) and H2-selective catalytic reduction (H2-SCR) aftertreatment was used to reduce NOx emissions. Turbocharging resulted in a maximum torque output of 168 N·m at 3200 rpm as compared to 70 N·m at 1600 rpm for the naturally aspirated operation. However, the turbocharger could not generate enough boost at low speeds and the equivalence ratio was increased to obtain a high power output which resulted in a substantial increase in the NOx emissions. The use of EGR resulted in an average reduction of 72% in the NOx emissions. Retarding of spark timing significantly reduced the NOx emissions too, but was limited by the adverse impact on the torque. Since hydrogen would be available onboard a hydrogen-fueled vehicle, we for the first time report external injection of H2 for use as a reductant in the selective catalytic reduction unit. Even under extremely oxidizing conditions, the efficiency of aftertreatment was found to be 35.4% averaged over various speeds. A maximum of 83.7% overall reduction in NOx emissions was achieved by using the combined EGR and H2-SCR strategies.

CORRELATIONAL ANALYSIS OF POLLUTANT EMISSION INTENSITY IN VARIOUS CONDITIONS OF OPERATION OF THE AUTOMOTIVE INTERNAL COMBUSTION ENGINE

The aim of this article was to analyse the correlation of emission intensity of carbon monoxide, hydrocarbons, nitrogen oxides, and carbon dioxide in various conditions of operation of the automotive internal combustion engine. The operational properties of the engine were investigated on chassis dynamometer in driving test cycles simulating various real-world conditions of the vehicle drive: street congestions, urban traffic without congestions, extra-urban traffic, and high-speed traffic. The correlational dependence of the pollutant emission intensity on the non-negative effective power of the engine and the correlational interdependence between the emission intensity of individual pollutants were investigated. The coefficients of Pearson’s linear correlation, Spearman’s rank correlation, Kruskal’s gamma correlation, and Kendall’s tau correlation were calculated. It was found that the emission intensity of pollutants in the driving test cycles strongly depends on the dynamic states of operation of the engine. The time histories of the emission intensity of pollutants were strongly correlated with the non-negative effective power of the engine. There were only a few cases where this correlation can be assessed as weak. The time histories of the emission intensity of individual pollutants were also strongly correlated with each other, with only a few exemptions.

The Effect of Compression Ratio by Different Piston Head Shape on the Performance of Motorcycle Engine

The compression ratio has a significant impact on engine power, fuel economy, emission, and other performances of internal combustion engines. Basic engine theory states that a higher compression ratio produces higher torque and horsepower. One way of having different compression ratio is by changing piston head shape. A piston is a cylindrical engine component that slides back and forth in the cylinder bore via forces produced during the combustion process. The piston acts as a movable end of the combustion chamber transmitting power generated from the burning of fuel and air mixture in the combustion chamber. The objective of this study is to compare the engine performance in horsepower and torque produced by the different shapes of the piston head in an internal combustion engine. Three pistons with different head shapes - standard, mug (low compression) and dome (high compression) with a compression ratio of 8.8:1, 7.61:1 and 10.06:1 were selected for the study. An experiment was also performed to a standard piston installed with 1.5 mm gasket, which has a compression ratio of 7.31. The experiments were carried out using a standard internal combustion engine of a Honda EX5 motorcycle. The engine runs on a chassis dynamometer to measure its torque and horsepower. Piston performance was evaluated based on the maximum available torque and horsepower. The result shows that all three pistons produce different torque and horsepower. The domed piston head produces higher torque and horsepower followed by the standard and mug. By just changing the piston head shape, torque and horsepower increased up to 7.14% and 20.05% respectively.

Flow characteristics of gas injectors

The operation of Internal Combustion Engine (ICE) with gaseous fuels is characterized by the specificity of the fuelling process. Nowadays the most common system is the one in which after lowering its pressure the gas fuel is delivered to the engine intake manifold by means of gas injectors. This leads to a difference in the laws of fuel supply relative to the original gasoline injection system that dispenses fuel in liquid phase. Theoretical research has been done and gas leakage has been found to be critical under engine normal operating conditions, that is, it depends on fuel pressure and not on the environment in which the fuel leaks (intake manifold). An experimental test stand was set-up and multiparametric characteristics of a common construction bottom feed gas injectors were determined experimentally under conditions very close to the real working ones.

Research on Top-Down Design Method of Internal Combustion Engine based on NX Future Development

With the development of internal combustion engine, how to design complicated parts of internal combustion engine quickly and effectively is of great significance. In view of the rapid prototyping design research of internal combustion engine parts, we firstly formulate a prototype model design criterion. From the sketch parameterization, shape feature parameterization and assembly parameterization design ideas, we propose a parameterized model construction method in order to meet the requirements of model accuracy and extensibility in the top-down design of internal combustion engine. Then according to the performance of internal combustion engine and the structure characteristics of main parts, we develop a system design process and a part design process. At the same time, we put forward a top-down design platform for internal combustion engine, analyse platform development functions, platform development framework and platform development process. Finally accomplishing the prototype of internal combustion engine based on NX development and a complete development technology system of internal combustion engine platform so as to improve the success rate of internal combustion engine design.

Thermoeconomic optimisation of small-scale organic Rankine cycle systems based on screw vs. piston expander maps in waste heat recovery applications

The high cost of organic Rankine cycle (ORC) systems is a key barrier to their implementation in waste-heat recovery (WHR) applications. In particular, the choice of the expansion device has a significant influence on this cost, strongly affecting the economic viability of an installation. In this work, numerical simulations and optimisation strategies are used to compare the performance and profitability of small-scale ORC systems using reciprocating-piston or single/two-stage screw expanders when recovering heat from the exhaust gases of a 185-kW internal combustion engine operating in baseload mode. The study goes beyond previous work by directly comparing these small-scale expanders for a broad range of working fluids, and by exploring the sensitivity of project viability to key parameters such as electricity price and onsite heat demand. For the piston expander, a lumped-mass model and optimisation based on artificial neural networks are used to generate performance maps, while performance and cost correlations from the literature are used for the screw expanders. The thermodynamic analysis shows that two-stage screw expanders typically deliver more power than either single-stage screw or piston expanders due to their higher conversion efficiency at the required pressure ratios. The best fluids for the proposed application are acetone and ethanol, as these provide a compromise between the exergy losses in the condenser and in the evaporator. The maximum net power output is found to be 17.7 kW, from an ORC engine operating with acetone and a two-stage screw expander. On the other hand, the thermoeconomic optimisation shows that reciprocating-piston expanders show a potential for lower specific costs, and since piston-expander technology is not mature, especially at these scales, this finding motivates further consideration of this component. A minimum specific investment cost of 1630 €/kW is observed for an ORC engine with a piston expander, again with acetone as the working fluid. This system, optimised for minimum cost, gives the shortest payback time of 4 years at an avoided electricity cost of 0.13 €/kWh. Finally, financial appraisals show a high sensitivity of the investment profitability to the value of produced electricity and to the heat-demand intensity.

Effects study of injection strategies on hydrogen-air formation and performance of hydrogen direct injection internal combustion engine

Based on the dual challenges of the global energy crisis and environmental pollution, hydrogen has been recognized as an ideal alternative internal combustion engine (ICE) fuel. To improve the combustion efficiency of hydrogen direct injection ICE, we numerically analyzed the effects of different injection parameters, including injection timing, injection pressure, and dual injection, on the formation of a hydrogen-air mixture using the CONVERGE software from the perspective of mass transfer and flow state. It was determined that it is enough to set the injection timing to −88° after top dead center (ATDC) for both uniform mixture and desirable indicated thermal efficiency (ITE). However, when the injection timing is set to −43° ATDC, an acceptable ITE and effective combustion can be achieved by employing the “jet-room coordination” effect of the ω chamber. Injection pressure has a minimal effect on mixture formation and combustion. In contrast, the timing and mass fraction of secondary injection have a significant influence on tumble strength, which is a key factor for the mixture improvement.

Study of the electric-booster and turbo-generator system and its influence on a 1.5 L gasoline engine

To effectively recovery the energy in exhausts and improve the transient performance of internal combustion engine. In this paper, a new electric turbo-compounding layout called electric-booster and turbo-generator system (EBTG) was established and studied in a 1.5 L gasoline engine. In the EBTG system, the turbo and compressor operate independently. Its impact on a gasoline engine was analyzed from the perspective of fuel economy, power output, availability distribution and transient performance. Results show that the proposed EBTG system is effective to improve the thermal efficiency of engine at high-speed and wide-open throttle conditions. Simultaneously, it is also valuable to solve the turbo-lag of engine. By applying EBTG system, the maximum reduction of specific fuel consumption was 2.6%. Exergy analysis showed that the EBTG system can reduce the irreversibility in turbine and recovery more exergy from exhausts. There was a 0.8 percentage point exergy efficiency increment at 4400 rpm and full-load operation. The step response time of boost pressure in EBTG engine decreased to about half of it in baseline at 2000 rpm and full-load condition.

Priming dose in distributed injection systems of overheated alcohol fuel

The expansion of the use of alcohol-containing fuels is evidenced by the release to the market of vehicles operating on benzoethanol mixtures E85 and E90, as well as on pure fuel ethanol E100. For regions with a temperate and cold climate (Russia, USA, Canada, Western Europe), the lack of fuel systems, which make it possible to launch and operate engines on pure alcohols (n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, tert-butyl), restrains, among other reasons, the widespread use of alcohols as motor fuels. According to numerous studies, an engine operating on pure alcohols can be started at temperatures above 10 ° C, at lower temperatures it becomes impossible to start and for its implementation at least 10-15% of the priming dose of gasoline is introduced into alcohols. The priming dose of gasoline in gas-alcohol mixtures can be replaced by a priming dose of alcohol injected into the intake manifold in a superheated state. This technical solution is proposed in patents for inventions of the Russian Federation of the authors. This article is devoted to the scientific and technical rationale for the efficiency of the use of pure superheated alcohols in injection systems and their impact on the effective performance of internal combustion engines with forced ignition.

The investigation of transesterification effect of Eruca sativa Madwort’s oil as biodiesel on performance and emissions of internal combustion engines

ABSTRACT As fossil fuel sources are being decreasing day by day, finding renewable energy resources are necessary. Biodiesel is one of the best alternatives in diesel engines. Eruca sativa Madwort (ESM), a nonedible plant and spice of Brassica carinata family, is one of the Iranian local oil seed plants that can grow in poor and unsuitable lands and has been used as an initial source of biodiesel in this study. Transesterification of ESM’s oil has been done using KOH as catalyst and methanol with protection of molar proportion of oil to alcohol (1:6). Indirect Spray Diesel engine (Lister M8.1) is used according to ECE-49 standard and different proportions of diesel fuel and biodiesel (B0, B5, B10, B20, and B35) are selected to investigate functional parameters and exhaust emission. The results show that with the increase in the percentage of the amount of biofuel in the fuel mixture, the amount of NO, NOx, and soot contamination reduce. Also, the diesel engine has best specific fuel consumption equal to 470 g/kw.h at B20. Other basic engine parameters such as power also remain in optimal condition. Finally, it is shown that ESM has good potential to replace the diesel fuel in diesel engines, without major modification in the design of engine and injection system.

Experimental evaluation of the performance and exhaust emissions of porous medium diesel and Otto engines

Nowadays, the porous medium engine as a new combustion concept is proposed to achieve high combustion efficiency and low emissions because of providing homogeneous combustion conditions. Rare experimental results have been reported about the effect of using porous media on the performance and exhaust emissions of internal combustion engines, in the previous researches. Therefore, in this paper the effect of using porous Otto and diesel engines on pollution emission, brake-specific fuel consumption (BSFC) and brake torque brake power is investigated. The results show a 70% reduction in CO and HC emission, 27% decrease in fuel consumption and negligible increase in NOx emission due to using porous media in the air manifold of Otto engine, while using porous media in combustion chamber of diesel engine reduces NOx emission by 35% and increases HC emissions by 35%. According to the results, the best place for use of porous media in internal combustion engines with the largest advantages is in the air manifold of Otto engine.

Research of CFR SI Engine and Dacia single cylinder SI engine equipped with LASER and Classical Spark Plug

Latest investigation has shown that laser ignition offers many potential benefits compared to the classical spark plug ignition due to the improvement of the performance of internal combustion engines. This paper aims to show the progress made in recent research on laser ignited internal combustion engines and also discusses the advantages and control opportunities, while considering the challenges faced and the prospects for its future implementation. It has been demonstrated that laser ignition can be used to improve the control of the engine in areas such as improved combustion stability, reductions in emissions, lower idle speed and leaner operation. Moreover, laser ignition not only that is non-invasive, but it also has a great flexibility in terms of the ignition position. Therefore, it allows the possibility of multi-point ignition. On the other hand, spark plugs offer limited possibilities for optimising engine efficiency, as their fixed position within a cylinder and the protrusion of electrodes disturbs the cylinder geometry and can also quench the flame kernel. As a result, this paper explores several results of the recent research focusing on: indicated, mediated pressures and their wave dispersion.

Mechanical Activation of Hydrocarbon Motor Fuels

Solving the problems of energy saving and reducing the load on the environment during the operation of internal combustion engines develops in different directions. One of the ways to reduce fuel consumption and reduce the amount of harmful emissions can be the use of an activator of liquid hydrocarbon fuel. Activator of motor hydrocarbon fuel (gasoline, diesel fuel, aviation kerosene, fuel oil) carries out processing of fuel, changing its composition and performance properties and is a highly efficient mechanical device. As a result of the action of the activator, the composition and properties of the hydrocarbon fuel change, the content of heavy fractions decreases, lighter and branched molecules appear, the sulfur and tar content decrease, and fuel consumption decreases. The decrease in the content of harmful emissions of CO, CH, CO2 in exhaust gases was experimentally established. Activated (structured) motor fuel, in addition to these advantages, increases the life of the engine by improving the organization of the working process in the engine cylinders, provides easier start-up at low temperatures and approaches the requirements of the Euro-5 certificate, regardless of the initial quality. This development provides solution of actual problems of energy saving and reduction of environmental pollution during operation of internal combustion engines.

An Experimental Investigation of Electrical and Thermal Performance of Battery Pack for Zero Emission Vehicle

A motor transport is a leading cause of the negative ecological situation and the excessive use of non-renewable resources. Increasing the volume of emissions from the operation of internal combustion engines and increasing consumption of hydrocarbon fuel are factors that stimulate the development of electric vehicles which are environmentally friendly and energy efficient. However, today electric vehicles are difficult to counter conventional cars in terms of cost and performance, determined mainly by characteristics and operating modes of traction battery packs. This article considers some topical issues related to the practical implementation of traction battery packs based on lithium-ion cells. The electric and thermal characteristics of the battery pack are considered by the authors in conditions of a discharge mode simulation. This is believed to be a the technical solution for the implementation of a modular battery pack, The present experimental investigations give qualitative and quantitative evaluation of the heat release of lithium nickel manganese cobalt oxide (NMC) cells and demonstrate the efficiency of the realized passive air cooling. This article partly fills the gap existing with regard to real (experimental) data on temperature conditions and heat release of NMC-cells in battery packs of electric vehicles.

Numerical investigation of combustion characteristics of a four-stroke single cylinder CI engine under various turbulence models

ABSTRACT This project deals with the flow analysis inside the combustion chamber and the validation process will be done by using various turbulence models. Enlightening the performance of internal combustion engines is the key effort of researchers. In the computational fluid dynamics, simulation is carried out by using STAR-CD software. The methods used for analysis are the Realizable k-ϵ model, RNG k-ϵ model, standard k-ϵ low Reynolds number model, and standard k-ϵ high Reynolds number model. These methods are chosen on the complexity of the problem. The obtained results will be validated with the experimental values. This paper assessed the complete performance of various turbulence models for modelling airflows in enclosed environments. Among various turbulence models Realizable k-ϵ model matches well with the experimental pressure with a deviation of 0.48%.

An Electric Load Simulator for Engine Camless Valvetrains

Camless valvetrains have become a promising direction to improve the performance of internal combustion engines. In this paper, an electric load simulator is proposed to simulate and implement gas force on the exhaust valve for camless valvetrains under semi-physical conditions. According to test data, the 1D gas-dynamic model was established to get boundary conditions and initial values for 3D finite element simulation. The 3D finite element simulation model was solved to obtain the gas force characteristics of the exhaust valve for camless valvetrains. The electromagnetic actuator was designed according to the system scheme and performance requirements of the electric load simulator. The PID (Proportion Integration Differentiation) algorithm was designed to control the output force of the electric load simulator and reproduce the gas force characteristics of the exhaust valve. It was found that the output force of the electric load simulator could follow the variation of the target gas force and meet the performance requirements of the electric load simulator based on simulation results and experimental results.

Cycle-to-Cycle Variation Analysis of Two-Colour PLIF Temperature Measurements Calibrated with Laser Induced Grating Spectroscopy in a Firing GDI Engine

<div class="section abstract"><div class="htmlview paragraph">In-cylinder temperatures and their cyclic variations strongly influence many aspects of internal combustion engine operation, from chemical reaction rates determining the production of NOx and particulate matter to the tendency for auto-ignition leading to knock in spark ignition engines. Spatially resolved measurements of temperature can provide insights into such processes and enable validation of Computational Fluid Dynamics simulations used to model engine performance and guide engine design.</div><div class="htmlview paragraph">This work uses a combination of Two-Colour Planar Laser Induced Fluorescence (TC-PLIF) and Laser Induced Grating Spectroscopy (LIGS) to measure the in-cylinder temperature distributions of a firing optically accessible spark ignition engine. TC-PLIF performs 2-D temperature measurements using fluorescence emission in two different wavelength bands but requires calibration under conditions of known temperature, pressure and composition. Here the TC-PLIF technique is calibrated in-situ using high precision (<1%) LIGS point measurements.</div><div class="htmlview paragraph">Temperature distributions were recorded during the compression stroke for fired operation with Direct Injection and with Plenum Fuel Injection of three two-component fuels containing toluene and iso-octane. Temperature inhomogeneity was observed for all fuels and injection strategies, with mm-scale regions having temperatures up to 10% higher than the local environment. Charge cooling of 3% due to direct injection was resolved.</div><div class="htmlview paragraph">Proper Orthogonal Decomposition (POD) was used to quantify the cycle-to-cycle variation of the temperature data. Low-order POD modes featured most of the cyclic variation in temperature and the corresponding mode coefficients were used to investigate correlations with combustion analysis, fuel injection strategies and toluene content of the fuel. Additionally, the low-order POD mode coefficients provided an opportunity to identify cycles containing local hotspots or outlier measurements.</div></div>

Simultaneous study on spray liquid length, ignition and combustion characteristics of diesel and hydrogenated catalytic biodiesel in a constant volume combustion chamber

Application of biodiesel is very important for reducing the consumption of fossil fuels and improving emissions performance of internal combustion engines in the transportation field. Hydrogenated catalytic biodiesel has attracted more attention due to the high quality and eco-friendly nature. Hence, in order to provide more fundamental data for applying this biodiesel in engines, the spray liquid length, ignition and combustion characteristics for both diesel and hydrogenated catalytic biodiesel has been researched in a constant volume combustion chamber to see their differences and similarities, which can be used for determination of the possible proportion of hydrogenated catalytic biodiesel in blends for further research in engines. The results show that the spray liquid length of hydrogenated catalytic biodiesel is shorter than that of diesel fuel, which indicates that hydrogenated catalytic biodiesel has better atomization and less chance for occurrence of wall-impingement. While a shorter ignition delay of hydrogenated catalytic biodiesel reveals that it cannot be applied in blends with a large proportion due to knocking combustion. However, a shorter ignition delay of hydrogenated catalytic biodiesel means that it is a highly active fuel which can be used to engines as a blend for new advanced combustion modes. The lift-off lengths were compared with different optical methodologies. Lift-off length is more sensitive to fuel properties rather than temperature under low ambient temperature conditions. The relationships between spray liquid length and lift-off length and between ignition delay and lift-off length were also compared.