Emissions Of Internal Combustion Engines Research Articles

Wheeled vehicles and environmental pollution

Urbanization and human activity have led to an increase in the negative impact on the environment in urban agglomerations. According to the UNECE, every year more than 3 million people die prematurely because of ambient air pollution. A significant role in this belongs to road transport, the polluting effect of which can be divided into the following main components: exhaust emissions of internal combustion engines; non-exhaust emissions (products of wear of friction pairs); pollution with fuels, lubricants and operational materials, as well as noise pollution. Emissions of non-exhaust particulate matter are among the most dangerous emissions of pollutants generated by the movement of wheeled vehicles. At the same time, scientific research and legal regulation in this area are insufficient for making informed decisions on the reduction of the impact of these emissions on the environment and public health. The article presents an overview of the main types of environmental pollution from cars, the priority directions of scientific research and development of the regulatory framework for reducing the negative impact on the environment from wheeled vehicles.

Design and performance evaluation of low-speed marine diesel engine selective catalytic reduction system

Selective catalytic reduction (SCR) systems are among the most effective methods used to reduce NOX emissions in internal combustion engines. SCR system performance is directly related to exhaust gas characteristics such as temperature and mass flow rate. Two-stroke engines commonly used in ships have different exhaust gas temperatures compared to four-stroke engines. In low-speed two-stroke diesel engines, the gas temperature drops after the exhaust gas expand in the turbocharger turbine, affecting SCR system performance. The main objective of this study is to determine performance parameters of marine SCR systems using computational fluid dynamics (CFD). The working processes of low-pressure SCR (LP-SCR) and high-pressure SCR (HP-SCR) systems were examined comparatively. The SCR system was modeled to include urea-water solution (UWS) decomposition and catalytic reduction reactions in the study. In the designed model, the amount of injected urea-water solutions (UWS), SCR bypass valve (RBV) opening, thermolysis and hydrolysis reactions, ammonia (NH3) slip and NOX reduction performances were investigated. In addition, pressure drop, velocity distribution and optimal catalyst length were determined on the model. The results showed that an increase in UWS reduces NOX emissions however increases the probability of NH3 slip. Increasing the RBV opening also reduced the pressure loss, which was beneficial to engine performance. However, the increasing RBV opening decreased the NOX reduction performance and increased the NH3 slip. The optimal SCR catalyst length was determined as 1200 mm. Furthermore, in the studies carried out under the same boundary conditions, the HP-SCR system meets the IMO Tier III standard, but it was observed that the LP-SCR system could not meet the standard due to the decreasing temperature in the turbine.

Oxy‐fuel combustion for carbon capture and storage in internal combustion engines – A review

As the impacts of global warming have become increasingly severe, oxy-fuel combustion has been widely considered a promising solution for carbon capture and storage (CCS) to reduce carbon dioxide (CO2) to achieve net-zero emissions. In the past few decades, researchers around the world have demonstrated improvements by the application of oxy-fuel combustion to internal combustion (IC) engines. This article presents a comprehensive review of the experimental and simulation studies about oxy-combustion for CCS in IC engines. To give a more comprehensive understanding, it has included a detailed explanation of the essential components contained in an oxy-fuel IC engine and its typical operating parameters. The oxy-fuel IC engine components include the system of oxygen supply, exhaust gas recirculation (EGR), water injection, fuel injection, and CCS. In order to optimise the combustion process, it is required to adopt the appropriate values for the oxygen concentration, EGR rate, ignition timing, compression ratio, fuel injection, and water injection in oxy-fuel engines. The detailed literature review and analysis presented provide a basis for the selection of oxy-fuel combustion for CCS as a prospective solution to reduce carbon emissions in IC engines.

Synergistic effect of textured piston ring and nano-lubricant on performance parameters and emissions of IC engine

Internal combustion (IC) engine is a prime emitter of greenhouse gases. The piston ring-cylinder liner pair plays a critical role in engine performance and exhaust emissions. Moreover, it accounts for major engine losses. The texturing on the piston ring and nano-material blended engine oil (nano-lubricant) have demonstrated promising results in their respective investigations on the IC engine. So far, most of the studies have been conducted on one of these approaches. Therefore, in this study synergistic effect of textured piston ring and nano-lubricant is investigated on performance parameters (fuel consumption, brake thermal efficiency, and brake specific fuel consumption) and engine emissions. The upper top compression piston ring is textured partially, and the nano-lubricant is prepared using silicate complexes nano-material [Mg6SiO10(OH)8] of 1% by weight with multi-grade engine oil (20W-40). The laser surface texturing technique (LST) is used to produce cylindrical textures on the piston ring with 6% texture density and 7.5% aspect ratio. Experiments have been conducted on a single-cylinder, direct injection, air-cooled, naturally aspirated compression ignition engine. All tests have been performed under different loading conditions (20%, 40%, 60%, 80% and 100% of full load). The synergistic effect of partially textured piston ring and nano-lubricant showed lower fuel consumption up to 4.58%, and nano-lubricant showed fuel reduction up to 3.23%. Furthermore, the exhaust emissions (CO, HC, and NOx) demonstrated a reduction that ranges from 0.24% to 10% compared to baseline data.

BIKE WORKING ON WATE

H2O otherwise known as hydroxy or Browns Gas is the gas produced from splitting water into hydrogen and oxygen from electrolysis and allowing the gas to stay in a premixed state for use on-demand without the need for storage. In 1918 Charles Frazer, a North American inventor, patented the first water electrolysis machine act as a hydrogen booster for internal combustion engines. Yull Brown, a Bulgarian born Australian inventor patented and attempted to popularize Browns Gas as a cutting gas and fuel additive during the 1970’s and 80’s. During the 2000’s there was a huge influx in Browns Gas devices coming to the mark, with many sensational claims of bringing dramatic reductions in fuel consumption and exhaust emissions in internal combustion engines.

Analysis of Driving Dynamics Considering Driving Resistances in On-Road Driving

Internal combustion engine emissions are a serious worldwide problem. To combat this, emission regulations have become stricter with the goal of reducing the proportion of transportation emissions in global air pollution. In addition, the European Commission passed the real driving emissions–light-duty vehicles (RDE-LDV) regulation that evaluates vehicle emissions by driving on real roads. The RDE test is significantly dependent on driving conditions such as traffic or drivers. Thus, the RDE regulation has the means to evaluate driving dynamics such as the vehicle speed per acceleration (v·apos) and the relative positive acceleration (RPA) to determine whether the driving during these tests is normal or abnormal. However, this is not an appropriate way to assess the driving dynamics because the v⋅apos and the RPA do not represent engine load, which is directly related to exhaust emissions. Therefore, in the present study, new driving dynamic variables are proposed. These variables use engine acceleration calculated from wheel force instead of the acceleration calculated from the vehicle speed, so they are proportional to the engine load. In addition, a variable of driving dynamics during braking is calculated using the negative wheel force. This variable can be used to improve the accuracy of the emission assessment by analyzing the braking pattern.

Improvement in accuracy of engine cycle simulations by using a turbocharger prediction model instead of measured efficiency map

In the downsizing concept, the turbocharger (T/C) is one of the key devices for improving thermal efficiency and exhaust emissions of internal combustion engines for automobiles. In order to maximize the supercharged engine performance, the size of the T/C applied for the given engine system has been optimized by using a 1-D engine cycle simulation. For this reason, T/C performance prediction model for engine cycle simulation is required to be accurate over a wide operating range. In the conventional T/C performance prediction model, the turbine performance was predicted by extrapolating from the efficiency map measured under steady flow. However, the accuracy of the extrapolation method is uncertain, and it has been pointed out that the prediction accuracy is low in the low load operations. In this study, a 1-D T/C model developed based on hydrodynamics and thermodynamics was used. Using the 1-D T/C model, a grid efficiency map over the entire operating range was calculated and the grid map was applied to 1-D engine cycle simulation. The accuracy of the T/C model was verified by comparing the experimentally measured efficiency under steady flow.

Effects of Fuel Ratio on Performance and Emission of Diesel-Compressed Natural Gas (CNG) Dual Fuel Engine


 
 
 Recent research breakthrough reveals that diesel-CNG dual fuel (DDF) combustion can potentially reduce exhaust emission of internal combustion engines. However, problem arises when knock phenomenon occurs producing high carbon monoxide (CO) and hydrocarbon (HC) emission due to uncontrolled blending ratio of diesel-CNG fuel on specific engine load. This study will determine the limit of dual fuel ratio before knock occurrence while analysing performance and exhaust emission of an engine operating with diesel and DDF fuel mode. A 2.5 litre 4-cylinder direct injection common-rail diesel engine was utilised as a test platform. The models tested were 100% Diesel, 90% DDF, 80% DDF and 70% DDF, representing diesel to CNG mass ratio of 100:0, 90:10, 80:20 and 70:30 respectively. It was found that DDF engine performance was lower compared to diesel engine at 1500 rpm engine speed. At higher engine speed, the 70% DDF showed engine performance comparable to diesel engine. However, high HC emission with knock onset and a decrease of Nitrogen Oxide (NOX) emission were recorded. This study suggests the preferred limit of dual fuel ratio should not be lower than 70% DDF which will be able to operate at high engine speed without the occurrence of knock and poor exhaust emission.
 
 

Effect of engine control parameters on combustion and particle number emission characteristics from a SIDI engine fueled with gasoline-ethanol blends

In this study, the impact of engine control parameters on combustion behaviors and particle number emissions was investigated with a spark ignition direct injection (SIDI) engine used various gasoline-ethanol blended fuels. The SIDI engine was tested with the E0, E30 and E85 at a engine operation of 1500 rpm/1.5 BMEP. The combustion pressure and mass burn fraction (MBF) according to the control parameters and ethanol fractions were analyzed. To verify the PN oxidation characteristics of the ethanol blended fuels, the size-resolved PN emissions over the three-way catalyst (TWC) were determined with a DMS500. The peak pressure in the cylinder was similar regardless of the type of fuel and the particle emissions were reduced by 92 % compared to gasoline at the engine out position in the E85 fuel. The results show that gasoline-ethanol blends have potential as alternative fuels and are effective in reducing the particle emissions in internal combustion engines.

Control of Organic Rankine Cycle, a neuro-fuzzy approach

Undesirable emissions in internal combustion engines are of major concern due to their negative effect on the human health and global warming. Implementing an organic Rankine cycle (ORC) in mobile applications can help to mitigate their negative effect by transferring some of their wasted heat into useful electrical or mechanical energy. Considering the stringent regulations in automobile industry ensuring the safety of equipment before implementing them on the vehicles is vital. In this study, a novel control approach is proposed to ensure the safe operation of Organic Rankine Cycle (ORC) waste heat recovery (WHR) system and stabilize its work output when subjected to transient heat sources in a range of waste heat from heavy-duty diesel engines. The control strategy comprises a neuro-fuzzy controller based on the inverse dynamics of the ORC system to control the superheating at the evaporator outlet by adjusting the pump speed and a PI controller to maintain the expander work output by regulating the mass flow rate at the expander inlet. The performance of the control strategy is investigated with respect to set-point tracking and its robustness is tested in the presence of noises. The simulation results indicate an enhancement in the controller performance by combination of feedforward and feedback controllers based on neuro-fuzzy technologies. The proposed control scheme not only can obtain satisfactory transient response under various loading conditions, but also can achieve desirable disturbance rejection performance.

Adaptive Air Charge Estimation Algorithm for Lean Burn SI Engines

Abstract The accuracy of cylinder air charge direct measurement affects air-fuel ratio (AFR) control performance and exhaust emissions of internal combustion engines, especially during the transient response. In lean combustion control, the combustion variation is higher than the normal combustion. Accurate air charge estimation is crucial in this combustion mode. Therefore, the methodology for the improvement of cylinder air charge estimation is required. With the effective air charge estimation method, the feedforward control of fuel injection can be precisely performed. This paper studies the performance of the adaptive air charge estimation algorithm on the lean operation mode. The results show that the applied algorithm is robust and has high efficiency for the cylinder air charge estimation.

Preface

Curtin University Malaysia hosted 2nd International Conference on Materials Technology & Energy (ICMTE) 2019 at its campus from 6 to 8 November 2019. The conference was co-organized with The Institution of Engineers Malaysia (IEM) Miri Branch and The Institution of Materials Malaysia (IMM) Miri Chapter with support from the Sarawak Convention Bureau (SCB) and Serba Dinamik Holdings Berhad, Malaysia.ICMTE 2019 provided a unique platform to exchange ideas on innovations, trends and future challenges related to materials technology, structures, construction, green energy, and industrial technologies. The conference hosted over 100 delegates, academics, researchers and industry professionals from Malaysia, Australia, Brunei, India, Indonesia, Singapore, UAE, Dubai, and South Africa to showcase their knowledge and expertise in different technologies focused on the above topics.The conference featured seven keynote speakers, such as Prof. Mohd. Nasir Tamin (University Teknologi Malaysia) who spoke on ‘Hybrid Experimental-Computational Characterisation of Materials for Reliability and Life Prediction Models’, Assoc. Prof. Yang Wenming (National University of Singapore) whose topic was ‘Fuel Design and its Impact on the Performance and Emissions of Internal Combustion Engines’, and Assoc. Prof. Ir. Chong Wen Tong (University of Malaya) who delivered a talk on ‘Innovative Wind Turbine Designs and Technologies’. Assoc. Prof. Sujan Debnath (Curtin University Malaysia) gave a presentation on ‘Mechanical Performance of Natural Fiber Polymer Composites Using Palm Oil Biomass’ while Dr. Suvash Saha (University of Technology Sydney) spoke on ‘Heat Transfer and Thermal Storage in Different Types of Heat Exchangers’. Dr. Ir. Wahyudi Sutopo (Universitas Sebelas Maret) talked about ‘Intervening for Accelerating a Technology Commercialisation in University using Early Supply Chain Integration’, and Assoc. Prof. Chithirai Pon Selvan (Curtin University Dubai), spoke about ‘Investigation of Process Parameters for Depth of Cut in Abrasive Waterjet Machining of Materials’.Apart from the keynote talks, 8 parallel sessions were hosted presenting the papers. A total of 88 papers have been submitted to the conference, out of which 66 papers have been selected for publication in the conference proceedings. The delegates found the conference an excellent opportunity for domestic and international participants to share their research findings and initiate collaboration in areas of recent technical advancements and innovation with regards to materials technology and energy. The conference ended with a half-day technical tour to the Sarawak BioValley Pilot Plant at the Curtin Malaysia campus, and a half-day master class on the interpretation of industrial welding codes.The organizers hope that these proceeding papers will be a good source of information for the relevant Scientific community from academia and industry.Editor(s)Dr. Sukanta Roy Dr. Yam Ke SanCurtin University Malaysia Curtin University Malaysia

Smoothed particle hydrodynamics modeling of fuel drop impact on a heated surface at atmospheric and elevated pressures.

The outcomes of fuel drop impact on heated walls will affect the fuel-air mixture distribution and the subsequent combustion and emissions in internal combustion engines. Existing numerical models for drop-wall interactions are mainly validated for conditions at atmospheric pressures. In this work, a numerical method, based on smoothed particle hydrodynamics, was developed to simulate the drop impact on a heated wall at high pressures. The effects of high temperature and high pressure on the evaporation of the drop were considered. The impact regimes under various wall temperatures and ambient pressures were identified, including deposit, contact splash, film splash, and rebound. Numerical predictions were validated by experimental observations. The present method predicted the increase in the critical temperature above which the drop would rebound as the ambient pressure increased. For example, for n-heptane drop impact on a 200 °C wall at We=50, the drop rebounds at 1 bar but deposits at 20 bars ambient pressure. The present method is able to capture the shift in the Leidenfrost point with the change in ambient pressure. The ability to predict such effects of the ambient pressure on drop-wall interactions is important in simulating spray impingement at realistic engine conditions.

Electronic Constant Twist Angle Control System Suitable for Torsional Vibration Tuning of Propulsion Systems

Currently, great emphasis on reducing energy consumption and harmful emissions of internal combustion engines is placed. Current control technology allows us to customize the operating mode according to the currently required output parameters, while the tuning of mechanical systems in terms of torsional vibration is often ignored. This article deals with a semi-active torsional vibroisolation system using pneumatic flexible shaft coupling with constant twist angle control. This system is suitable, as it is specially designed, for the tuning of mechanical systems where the load torque has fan characteristics (fans, ship propellers, pumps). The main goal of this research is to verify the ability of an electronic control system developed by us to maintain the pre-set constant twist angle of the used pneumatic flexible shaft coupling during operation. The constant twist angle control function was tested on a laboratory torsional oscillating mechanical system. Presented results show that the proposed electronic control system meets the requirements for its function, namely that it can achieve, sufficiently accurately and quickly, the desired constant twist angle of the pneumatic flexible shaft coupling. It is possible to assume that the presented system will increase the technical level of the equipment where it will be applied.

Analysis of the combustion process in a lean-burning turbulent jet ignition engine fueled with methane

Recent needs of reducing pollutant emissions of internal combustion engines have pushed the development of non-conventional ignition systems. One of the most promising techniques appears to be the so-called Turbulent Jet Ignition (TJI) system, in which a jet of high-energy reactive gases is generated by means of a pilot combustion in a pre-chamber and used to initiate the main combustion event in the cylinder. Considering the complex nature of some phenomena typical of TJI systems, 3D CFD studies are essential to provide a detailed analysis for an efficient design. In this study, numerical simulations of an active pre-chamber TJI system applied to a lean operating methane engine were performed to provide a thorough analysis of the combustion process that characterizes such a technology. The numerical model was validated against experimental measurements carried out on an optically accessible single cylinder spark-ignition engine equipped with the pre-chamber prototype. The numerical simulations provided an insight view of both physical and chemical phenomena occurring inside the pre-chamber otherwise difficult to achieve by experiments alone. The evolution of some species of interest was analyzed in order to study the main charge ignition process, as well as the overall combustion progress. The results show that the main charge ignition is made possible by the large amount of energy and active radicals released from the pre-chamber and this ensures an overall stable and faster combustion in lean conditions. The performance improvements of the TJI system with respect to a traditional spark-ignition engine were evaluated in terms of efficiency and pollutant emission levels.

Gasoline Particulate Filter Accelerated Aging Processes - a Literature Review

This article briefly presents the testing processes of vehicle and engine testing on chassis and engine dynamometers in a laboratory environment and their development trend due to the stricter environmental regulations. It then explains the test cycles that form the basis of the measurements and their effect on emissions and components of the exhaust system. It briefly summarizes the potential processes of soot formation. It researches and describes the possibilities of reducing the duration and costs of testing and inspection processes in the field of particulate emissions of internal combustion engines.

Analysis of combustion acoustic phenomena in compression–ignition engines using large eddy simulation

As computational capabilities continue to grow, exploring the limits of computational fluid dynamics to capture complex and elusive phenomena, which are otherwise difficult to study by experimental techniques, is one of the main targets for the research community. This paper presents a detailed analysis of the physical processes that lead to combustion noise emissions in internal combustion engines. In particular, diesel combustion in a compression–ignition (CI) engine is studied in order to understand the singular behavior of the in-cylinder flow field responsible for the acoustic emissions. The main objective is, therefore, to improve the understanding of the phenomena involved in CI engine noise using large eddy simulations. Several visualization methods are employed to investigate the connection between combustion behavior and its effects on the pressure field. In addition, proper orthogonal decomposition is used to analyze the modal energy distribution among all the acoustic modes. The results show that the acoustic signature is fundamentally conditioned by the intensity of the premixed combustion rather than by the pressure oscillations generated by turbulent fluctuations in the flame surface established during the diffusion stage.

Nozzle rate of injection estimation from hole to hole momentum flux data with different fossil and renewable fuels

Due to environmental problems, research on fuel economy and pollutant emissions in internal combustion engines has drawn the attention of automobile manufacturers and researchers. The diesel engine is one of the most efficient alternatives and one of the main areas of the study in these engines is spray mixing, recognized as a critical factor in combustion control and the reduction of its related contaminants.The studies about fuel sprays rely on experimental data of the rate of injection, which can only be obtained with high-cost equipment. The aim of this paper is to validate for different fuels a method for the determination of the rate of injection based on spray momentum measurements and the total injected mass. After a proper tuning of the test momentum flux device, the injection rate results were validated using the Bosch tube method. The technique was validated for four different fuels, diesel, biodiesel, GTL (Gas-to-liquid) and Farnesane, in order to identify the consequences of the fuel properties on the injection performance characteristics and the estimation method.The results of rate of injection following the procedures presented showed good accuracy when compared to experimental values. These methods can be employed to estimate this parameter when experimental facilities for this purpose are not available.

An emission analysis study of hydrogen powered vehicles

In this study, emissions of internal combustion engine, hybrid, and fuel cell vehicles have been investigated when they use hydrogen in gas or liquid form. Well to pump (WTP) and well to wheel (WTW) emissions of volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NOx), particulate matters (PM10 and PM2.5), sulphur oxides (SOx), and carbon dioxide (CO2) emitted from vehicles are compared for scenarios in 2010, 2020, 2030, 2040, and 2050 years. For these years, 2005, 2015, 2025, 2035, and 2045 vehicle technologies are used in the analyses. In total emissions, gaseous hydrogen (GH2) powered fuel cell vehicles (FCV) appear to be the best options, while liquid hydrogen (LH2) powered spark ignition internal combustion engine vehicles (SI ICEV) are the worst. The lowest and highest CO2 emission values are seen as 81 g/km and 416 g/km in GH2 powered FCVs in 2050 and LH2 powered SI ICEVs in 2010, respectively.

Implementation of the Semi Empirical Kinetic Soot Model Within Chemistry Tabulation Framework for Efficient Emissions Predictions in Diesel Engines

Abstract Soot prediction for diesel engines is a very important aspect of internal combustion engine emissions research, especially nowadays with very strict emission norms. Computational Fluid Dynamics (CFD) is often used in this research and optimisation of CFD models in terms of a trade-off between accuracy and computational efficiency is essential. This is especially true in the industrial environment where good predictivity is necessary for engine optimisation, but computational power is limited. To investigate soot emissions for Diesel engines, in this work CFD is coupled with chemistry tabulation framework and semi-empirical soot model. The Flamelet Generated Manifold (FGM) combustion model precomputes chemistry using detailed calculations of the 0D homogeneous reactor and then stores the species mass fractions in the table, based on six look-up variables: pressure, temperature, mixture fraction, mixture fraction variance, progress variable and progress variable variance. Data is then retrieved during online CFD simulation, enabling fast execution times while keeping the accuracy of the direct chemistry calculation. In this work, the theory behind the model is discussed as well as implementation in commercial CFD code. Also, soot modelling in the framework of tabulated chemistry is investigated: mathematical model and implementation of the kinetic soot model on the tabulation side is described, and 0D simulation results are used for verification. Then, the model is validated using real-life engine geometry under different operating conditions, where better agreement with experimental measurements is achieved, compared to the standard implementation of the kinetic soot model on the CFD side.