In engine 30% of the total energy is lost due to the friction between piston ring and cylinder liner due to their constant rubbing motion. A piston that reciprocates at high speeds has piston rings that constantly scrape against the wall leading to high frictional losses within the engine. The engine has to work against this resistance to provide the required power, and hence it will consume more fuel. For this reason, material used for these components is more crucial. Reduction of surface friction between moving parts in order to increase overall efficiency can be achieved by suitable coating. The most commonly used piston rings are coated with chromium layers that are electroplated which is being replaced by chrome plating. Low coefficient of friction (COF) and high wear resistance can be achieved by self-lubricating coating of PTFE and PEEK polymer-based composite coatings.
During investigation of an automotive shock absorber endurance test where it was supposed to last at least 200,000 load cycles but that did not meet the mandatory fatigue requirement. This is because of the failure in the shock absorber shim assembly. This failure was due to Fretting fatigue. Design improvement is carried out to avoid the fretting fatigue phenomenon on the shock absorber shim assembly. Using FEA some analysis is done over the shim assembly to determine the stress region. At last after increasing the shims in the piston important improvement in fatigue life was achieved. This improvement was obtained with simple solution, without effecting the damping forces.
The goal of this research is to study the efficiency and emissions of diesel in combination with linseed and jatropha oil as biodiesels. These oils were trans-esterified and three ternary blends of ethanol, biodiesel, and diesel were prepared in E10-B20, E15-B20, and E20-B20 configurations. Ethanol is used as an additive to improve combustion properties. Brake power and emission tests were carried out using ternary biodiesel mixtures in a computerized single-cylinder water-cooled diesel engine. These novel ternary blends exhibit lower NO 2 and CO 2 emissions than normal diesel fuel. From the performance point of view, the blend E10-B20 has similar SFC and brake thermal efficiency to diesel. The E15-B20 blend displayed a significant reduction of around 50 % in unburnt hydrocarbons in comparison with the base diesel at heavy load conditions. In addition, the NOx value also dropped by 28% in comparison with the E15-B20 blend with base diesel at heavy load conditions.
Disposal of non-biodegradable plastic waste is one of the major hindrances for many countries. The research works in area of plastic waste management expands almost like every day. The conversion of waste to energy recovery is one of the promising techniques found to manage the waste plastic. Waste plastics have the dominating factor for fuel production since they have good heat of combustion and also their growing availability. The present work examines the potential of using blends of plastic oil (PO) with diesel in a direct injection diesel engine. The plastic oil is synthesized through pyrolysis process from mixed plastic waste, which has got more potential for scalable implementations. The present work includes the production of PO, characterization of the produced PO, performance and emission testing in a single cylinder four stroke VCR multi fuel engine. The engine is fueled with blends of plastic oil with diesel.
Interest in the use of kerosene fuel in diesel engines has garnered researchers’ attention in the past few years due to its improve premixed combustion and its ability to decrease soot emission. The potential of using kerosene in the design stage of a diesel engine is thus a great motivator to study fuel spray development and to evaluate known fuel spray tip correlations and models with respect to their predictive capability with such a fuel. Therefore, the present paper proposes to investigate the spray development of a multi-hole solenoid injector fueled with kerosene under non-evaporative conditions. Moreover, the experimental results are used to evaluate how different phenomenological models proposed in the literature for diesel fuel are able to predict kerosene spray tip penetration. The experimental test rig is composed of a constant-volume pressurized vessel and a camera allowing to visualize the liquid phase using a backlight illumination technique.
Argon Power Cycle (APC) engine is an innovative power system for high efficiency and zero emissions, which employs an Ar-O2 mixture rather than air as the working substance. However, APC engines face the challenge of knock suppression. Compared to hydrogen, methane has a better anti-knock capacity and a larger thermal conversion efficiency, thus is an excellent potential fuel for APC engines. In previous studies of methane-fueled APC engines, the methane is injected into the intake port. Nevertheless, for lean combustion, the stratified in-cylinder mixture formed by methane direct injection has superior combustion performances. Therefore, based on a methane direct injection engine at compression ratio=9.6 and 1000 r/min, this study experimentally investigates the effects of replacing air by Ar-O2 mixture (79%Ar+21%O2) on efficiencies, loads, and other combustion characteristics under different excess oxygen ratios.
Conventional diesel combustion (CDC) is known to provide high efficiency and reliable engine performance, but often associated with high particulate matter (PM) and nitrogen oxides (NOX) emissions. Combustion of fossil diesel fuel also produces carbon dioxide (CO2), which acts as a harmful greenhouse gas (GHG). Renewable and low-carbon fuels such as renewable diesel (RD) and methanol can play an important role in reducing harmful criteria and CO2 emissions into the atmosphere. This paper details an experimental study using a single-cylinder research engine operated under dual-fuel combustion using methanol and RD. Various engine operating strategies were used to achieve diesel-like fuel efficiency. Measurements of engine-out emissions and in-cylinder pressure were taken at test conditions including low-load and high-load operating points.
According to the AEO2022 report, almost 30% of the transport sector will still use internal combustion engines (ICE) until 2050. Small and light-duty vehicles can be electrified with an acceptable range, and the market has already moved in this direction. Equipment used for heavy-duty (HD) applications will continue to use fossil fuels as the primary energy source due to the challenges of providing comparable energy storage in HD electric vehicles. However, the transportation sector has been actively seeking different methods to reduce the CO2 emissions footprint of fossil fuels. The use of lower carbon-intensity fuels such as Renewable Diesel (RD) can enable a pathway to decarbonize the transport industry. This suggests the need for experimental or advanced numerical studies of RD to gain an understanding of its combustion and emissions performance. This work presents a numerical modeling approach to study the combustion and emissions of RD.
Methanol is a suitable alternative fuel to relieve the problem of energy shortage and decrease the emission of greenhouse gases. The effect of direct injection timing of methanol and diesel on the combustion characteristics of a marine diesel engine with bore of 0.21 m was simulated with a 3-dimentional computational fluid dynamic (CFD) software AVL-FIRE. The combustion model was set-up and validated by the experimental data from the marine diesel engine. Results show that there are two peaks on the heat release rate (HRR) curves with the normal diesel-methanol combustion process. The first HRR peak is caused by the combustion of diesel. The second HRR peak is resulted from the hybrid combustion process of diesel and methanol. The injection timing of diesel influences the maximum pressure rise rate (PRRmax) and ignition timing.
Compression ignition engines used in heavy-duty applications are typically powered by diesel fuel. The high energy density and feedstock abundance provide a continuing source for the immense energy demand. However, the heavy-duty transportation sector is challenged with lowering greenhouse gas and combustion by-product emissions, including carbon dioxide, nitrogen oxides, and particulate matter. The continuing development of engine management and combustion strategies has proven the ability to meet current regulations, particularly with higher fuel injection pressure. Nonetheless, a transition from diesel to a renewable alternative fuel source will play a significant role in reducing greenhouse gases while maintaining the convenience and energy-dense inherent of liquid fuels. Dimethyl ether is a versatile fuel that possesses combustion properties suitable for compression ignition engines and physical properties helpful for clean combustion.
The forthcoming Euro 7 emissions legislation will regulate emissions of ammonia for the first time from light duty vehicles. Most light duty vehicles are powered by gasoline spark ignition engines and gasoline direct injection is a predominate technology. Sources of ammonia emission from such engines can be in-cylinder reactions (i.e. combustion) or downstream reactions across aftertreatment devices, particularly three-way catalysts. The latter, because they are the major contributor to gasoline vehicle ammonia emissions, has been the subject of many investigations. The former, less so, and hence are the subject of this work using a comprehensive chemical kinetics mechanism in a two-zone spark ignition engine model validated against experimental heat release and emissions data.
The supercritical fluid combustion technology was regarded as an effective method to increase fuel gas mixing rate and performance. During the injection and combustion process, critical characteristics dominate the jet development to behave as different spray structure. Due to the limited researches about supercritical gasoline-like fuel injection characteristics, macroscopic and near-nozzle microscopic spray structure was observed respectively. In this work, a supercritical gasoline -like fuel injection device was designed able to heat the fuel temperature up to 773 K and maintain the fuel injection pressure stable at 4 MPa. The experiment was conducted with the fuel injecting from supercritical condition to atmosphere condition. As a comparison, two fluids were selected to conduct injection experiment. The n-heptane was used to represent the surrogate of the supercritical gasoline, while the cryogenic nitrogen was selected to represent the ideal gas.
This paper presents a method to analyse the characteristics of nano-scale particles emitted from a 1.6 Litre, 4-stroke, gasoline direct injection (GDI) and turbocharged spark ignition engine fitted with a three-way catalytic converter. Ensemble Empirical Mode Decomposition (EEMD) is employed in this work to decompose the nano-scale particle size spectrums obtained using a differential mobility spectrometer (DMS) into Intrinsic Mode Functions (IMF). Fast Fourier Transform (FFT) is then applied to each IMF to compute its frequency content. The results show a strong correlation between the IMFs of specific particle ranges and the IMFs of the total particle count at various speed and load operating conditions. Hence, it is possible to characterise the influence of specific nano-scale particle ranges on the total particulate matter signal by analysing the frequency properties of its IMFs using the EEMD-FFT method.
Several governments are increasing the blending mandate of renewable fuels to reduce the life-cycle greenhouse gas emissions of the road transport sector. Currently, ethanol is a prominent renewable fuel and is used in low-level blends, such as E10 (10 %v/v ethanol, 90 %v/v gasoline) in many parts of the world. However, the exact concentration of ethanol amongst other renewable fuel components in commercially available fuels can vary and is not known. To understand the impact of the renewable fuel content on the emissions from Euro 6d-Temp emissions specification vehicles, this paper examines the real-driving emissions (RDE) from four 2020 to 2022 model-year vehicles run on E0 and E10 fuels. CO, CO2, NO, and NO2 were measured through a Portable Emissions Measuring System (PEMS).
It is a well-known fact that HCCI combustion offers the possibility of achieving high efficiency with low emissions, but with the challenges in combustion control and ability to adjust to changing environmental conditions. To resolve the aforementioned challenges, a pre-chamber induced homogeneous charge compression ignition (PC-HCCI) combustion mode was experimentally tested with aim of providing initial boundaries of combustion stability and obtaining initial performance results. The single cylinder engine equipped with active prechamber and compression ratio of 17.5 was fueled by gasoline. The engine speed was fixed to 1600 rpm with intake air temperatures varied from 33 to 95°C. The initial experiments were performed to verify the possibility of PC-HCCI combustion mode. Parameters that were varied were pre-chamber fuel mass and spark timing at different air excess ratios in the main chamber.