Search Results

Abstract This study demonstrates the defossilized operation of a heavy-duty port-fuel-injected dual-fuel engine and highlights its potential benefits with minimal retrofitting effort. The investigation focuses on the optical characterization of the in-cylinder processes, ranging from mixture formation, ignition, and combustion, on a fully optically accessible single-cylinder research engine. The article revisits selected operating conditions in a thermodynamic configuration combined with Fourier transform infrared spectroscopy. One approach is to quickly diminish fossil fuel use by retrofitting present engines with decarbonized or defossilized alternatives. As both fuels are oxygenated, a considerable change in the overall ignition limits, air–fuel equivalence ratio, burning rate, and resistance against undesired pre-ignition or knocking is expected, with dire need of characterization.

Abstract Fossil fuel reserves are swiftly depleting when consumer demand for these fuels continues to rise. In order to meet the demand and diminish the pollution derived through conventional fuels, it is crucial to employ cleaner fuels made from substitutes such as waste biomass. Also, converting waste biomass to fuel can lower usage of landfills. There are many biomass resources that are suitable for fuel production, out of which groundnut is also a potential feedstock. Groundnut shell biomass was chosen for this study, as it is a waste leftover during shelling of groundnuts for various commercial applications. The procured groundnut shells were converted to oil using pyrolysis process and was distilled. Both the pyrolysis oil and the distilled oil were analyzed using Fourier transform infrared instrument wherein the presence of functional groups such as alcohols, amines, and carboxylic acids were identified.

Abstract Various feedstocks can be employed for biodiesel production, leading to considerable variation in composition and engine fuel characteristics. Using biodiesels originating from diverse feedstocks introduces notable variations in engine characteristics. Therefore, it is imperative to scrutinize the composition and properties of biodiesel before deployment in engines, a task facilitated by predictive models. Additionally, the international commercialization of biodiesel fuel is contingent upon stringent regulations. The traditional experimental measurement of biodiesel properties is laborious and expensive, necessitating skilled personnel. Predictive models offer an alternative approach by estimating biodiesel properties without depending on experimental measurements. This research is centered on building models that correlate mid-infrared spectra of biodiesel and critical fuel properties, encompassing kinematic viscosity, cetane number, and calorific value.

Abstract The ASTM D130 was first issued in 1922 as a tentative standard for the detection of corrosive sulfur in gasoline. A clean copper strip was immersed in a sample of gasoline for three hours at 50°C with any corrosion or discoloration taken to indicate the presence of corrosive sulfur. Since that time, the method has undergone many revisions and has been applied to many petroleum products. Today, the ASTM D130 standard is the leading method used to determine the corrosiveness of various fuels, lubricants, and other hydrocarbon-based solutions to copper. The end-of-test strips are ranked using the ASTM Copper Strip Corrosion Standard Adjunct, a colored reproduction of copper strips characteristic of various degrees of sulfur-induced tarnish and corrosion, first introduced in 1954. This pragmatic approach to assessing potential corrosion concerns with copper hardware has served various industries well for a century.

Abstract Quantifying exhaust gas composition and temperature in vehicles with internal combustion engines (ICEs) is crucial to understanding and reducing emissions during transient engine operation. This is particularly important before the catalytic converter system lights off (i.e., during cold start). Most commercially available gas analyzers and temperature sensors are far too slow to measure these quantities on the timescale of individual cylinder-firing events, thus faster sensors are needed. A two-color mid-infrared (MIR) laser absorption spectroscopy (LAS) sensor for gas temperature and carbon monoxide (CO) mole fraction was developed and applied to address this technology gap. Two quantum cascade lasers (QCLs) were fiber coupled into one single-mode fiber to facilitate optical access in the test vehicle exhaust. The QCLs were time-multiplexed in order to scan across two CO absorption transitions near 2013 and 2060 cm–1 at 15 kHz.

Abstract The Coordinating Research Council (CRC) is actively involved in developing and applying advanced analytical techniques to the chemical characterization of transportation fuels. This article complements a 2017 CRC project to quantify and compare the effects of a commercially available renewable diesel fuel (hydrotreated vegetable oil [HVO]) and an ultralow sulfur diesel (ULSD) fuel on engine-out gaseous and particulate matter (PM) emissions from a light-duty vehicle. Results showed that the combustion of HVO fuel had an advantage over ULSD in terms of lowering engine-out emissions (THC, CO, NOx, etc.). Furthermore, this advantage is strongly related to the fuel composition. This article summarizes the results of advanced and comprehensive analytical tests on the same ULSD and HVO fuels and attempts to connect some of the engine-out emissions results to fuel composition and specific chemical structures.

Abstract An aeroengine exhaust plume is one of the important sources of infrared (IR) signature in the 3-5 μm and the 2-3 μm bands. Analysis, characterization, and modeling of the exhaust plume IR emission are needed for insight into its role in aircraft survivability against IR-guided missiles. The IR signature estimation of aeroengine exhaust needs estimation of radiative properties of absorbing-emitting exhaust gases, e.g., carbon dioxide (CO2) and water vapor (H2O). The radiative properties of the gases can be estimated by a mathematical model with a spectroscopic database of these gases. Low-Resolution Transmission (LOWTRAN), Moderate-Resolution Transmission (MODTRAN), High-Resolution Transmission (HITRAN), and High-Temperature Transmission (HITEMP) are some commonly used spectroscopic databases. This study compares Statistical Narrowband (SNB) models with the various other mathematical models used for the estimation of radiative properties of exhaust gases.

Abstract A reproducible analytical test method was developed to quantify the fouling resistance and cleanability of camera lens covers for autonomous vehicles (AVs). Reproducible fouling and cleaning cycles were achieved using a custom-built laboratory test stand. The impact of fouling/cleaning on image quality was quantified using digital image analysis. Three optically transparent, fluorine-containing functional coatings on lens covers were used to validate the test method. Accelerated weathering was employed to deliberately degrade the functional coatings. Coating degradation was characterized using water contact angle and X-ray photoelectron spectroscopy. The effect of coating degradation on cleaning performance was studied using this test method. This analysis method was able to characterize differences in coating performance and can be used as a tool to evaluate next-generation functional coatings for autonomous vehicles.

Abstract The hot corrosion studies for the die-casted magnesium (Mg) silver (Ag) alloys are carried out through the steam heating route. The Magnesium Silver (QE22A) alloy is fixed under the top lid of the pressure cooker (2 liters) and filled with water and 5% salt (NaCl) solution. The specimens are treated with different time intervals (10, 20, and 30 minutes), with the steam temperature maintained at 100°C around the specimen. The results showed an increase in the corrosion rate with the increase in the steaming time. Further, after the specimens have cooled down to room temperature, similar experiments are repeated for the second and third cycles. Here the formation of the oxide layers over the specimen has reduced the corrosion rate. The structural, surface study was carried out through scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive spectroscopy (EDS) to know the corrosion behavior on the specimen.

Abstract Electrochemical impedance spectroscopy (EIS) is widely used to diagnose the state of health (SOH) of lithium-ion batteries. One of the essential steps for the diagnosis is to analyze EIS with an equivalent circuit model (ECM) to understand the changes of the internal physical and chemical processes. Due to numerous equivalent circuit elements in the ECM, existing parameter identification methods often fail to meet the requirements in terms of identification accuracy or convergence speed. Therefore, this article proposes a novel impedance model parameter identification method based on the random mutation differential evolution (RMDE) algorithm. Compared with methods such as nonlinear least squares, it does not depend on the initial values of the parameters. The method is compared with chaos particle swarm optimization (CPSO) algorithm and genetic algorithm (GA), showing advantages in many aspects.

Abstract Biodiesel was found to be the best candidate to replace diesel fuel mainly due to being renewable, biodegradable, and non-toxic and reduce greenhouse gases, which cause global warming. Nowadays, biodiesel is blended with diesel fuel in different concentrations depending on the country of usage and is used in diesel engines. Concerns about biodiesel were raised after premature fouling of fuel filters were reported before meeting their mileage requirement. Three filters from Brazil were analyzed using different techniques (Energy Dispersive X-Ray [EDX], Fourier Transform Infrared Spectroscopy [FTIR], Thermogravimetric Analysis [TGA], Time of Flight-Secondary Ion Mass Spectrometry [ToF-SIMS], and Gas Chromatography/Mass Spectrometry [GC/MS]) to understand the chemical composition of the filter deposits and highlight the main compounds responsible for the blockage.

Abstract The acidification of lubricating oils during engine operation, and the subsequent additive neutralization, is an important challenge for Original Equipment Manufacturers and end-users. Often the decline in Total Base Number (TBN) and increase in Total Acid Number (TAN) is measured during engine operation as an indication of the oil’s condition and lifetime. This is clearly an oversimplification given that no consideration is given to the type of acid, how corrosive it is, or the type of base and how effective it is at neutralizing. Acids can be broadly categorized into mineral acids such as sulfuric/nitric and organic acids such as acetic. Traditionally, research has focused on understanding the effects of mineral acids such as sulfuric, which can be formed during the combustion of sulfur-containing fuel.

Abstract In this work, an in situ multispecies portable emission measurement system (PEMS) is presented. The system is based on tunable diode laser absorption spectroscopy (TDLAS) and is capable of measuring tailpipe emissions without the necessity of online calibration. It is intended for application on passenger cars within the real drive emission (RDE) procedure of the Worldwide Harmonized Light Duty Test Procedure (WLTP). In contrast to the extractive measurement principles of commercially available PEMS, the introduced measurement system does not require gas sampling or preconditioning and thus does not suffer from the same low-pass filter effects on the measurements. These differences are suspected to have an impact on certification-relevant measurement data. Measurements have been conducted on a 3-cylinder 1 liter EURO 6 b gasoline engine test bench to investigate the differences between the presented measurement system and a commercially available PEMS.

Abstract The transportation industry is currently in a transition toward the use of zero-emission vehicles; however, reaching it will take a considerable amount of time. In the meantime, a diesel powertrain will remain the workhorse for most heavy-duty transportation. In order to reduce the engine’s environmental impact, biofuels, such as biodiesel, are used as drop-in fuels or fuel blends. The use of drop-in fuels may create challenges for the fuel system since sticky deposits can precipitate and cause injector malfunctioning or premature fuel filter plugging. It has been concluded in the past that these deposits have been caused by soft particles. In this article, soft particles created through the degradation of biodiesel and their effect on filters are studied. The article aims to analyze fuel filters and investigate the materials responsible for soft particle separation. The study includes three pre filters and three main filters that are commercially available truck filters.

Abstract Sustainable practices are taking precedence across many industries, as evident from their shift towards the use of environmentally responsible materials, such as natural fiber-reinforced acrylated epoxidized soybean oil (NF-AESO). However, due to the lower reactivity of AESO, the curing reaction usually requires higher temperatures and longer curing time (e.g., 150°C for 6-12 h), thus making the entire process unsustainable. In this study, we demonstrate the potential power of photons towards manufacturing NF-AESO composites in a sustainable manner at room temperature (RT) within 10 min. Two photoinitiators, i.e., the 2,2-dimethoxy phenylacetophenone (DMPA) and 1-hydroxycyclohexyl phenyl ketone (HCPK), were evaluated and compared with the thermal initiator, i.e., tert-butyl perbenzoate (TBPB). Based on the mechanical performance of the AESOs, the photoinitiation system for NF-AESO was optimized.

Abstract Artificial intelligence-based computing systems like artificial neural networks (ANN) have recently found increasing applications in predicting complex chemical phenomena like combustion properties. The present work deals with the development of an ANN model that can predict the derived cetane number (DCN) of oxygenated fuels containing alcohol and ether functionalities. Experimental DCNs of 499 fuels comprised of 116 pure compounds, 222 pure compound blends, and 159 real fuel blends were used as the dataset for model development. DCN measurements of sixty new fuels were carried out in the present work, and the data for the rest were collected from the literature.

Abstract Neutralization of acidic contaminants in engine lubricating oil is an important topic for engine manufacturers. Often, the deterioration in total base number (TBN) and increase in total acid number (TAN) during engine test operation is used as an indication of oil lifetime. This is clearly an oversimplification given that no consideration is given to how corrosive the acid is, and how effective the base is at neutralizing different acids. The work detailed here will explore how the presence of inorganic acids can be combated by lubricant additives, such as overbased detergents, through rapid neutralization. To achieve this, stopped-flow UV/visible spectroscopy has been used to measure the reaction kinetics between an overbased detergent and sulfuric acid containing water-in-oil (w/o) microemulsion droplets. The key structural properties of overbased detergents that contribute to effective acid neutralization will be explored.

Abstract Intake-runner fluid dynamics represent a vital component in the global performance of internal combustion engines, but limited diagnostics exist to characterize these gas flows. In this work, a laser absorption-based sensor was developed to measure intake-runner gas temperature, pressure, and water (H2O) mole fraction with crank-angle resolution. The sensor was designed to target two temperature-sensitive 1.8 μm absorption transitions in ambient H2O vapor. A high-resolution study of both lines was conducted, and a novel, multi-harmonic wavelength-modulation-spectroscopy (WMS) detection technique was developed to achieve sensitive measurements at 31 kS/s (once per crank angle degree at 6000 RPM). The sensor was validated in the laboratory across a range of intake-relevant conditions and subsequently demonstrated during dynamometer (dyno) testing of a single-cylinder development engine under motored and fired conditions.

Abstract Engine oils have complex packages of additives aimed at improving their tribological properties. However, interactions between elements of these additives may hinder the cooling ability of these oils. The current article addresses the influence of the interaction between chemical elements of oil additives on the cooling capacity of oils for different wall superheats (0°C-150°C) and oil bulk temperatures (60°C, 100°C, and 150°C). A back-propagation neural network (BPNN) is used to conduct the present work. The NN is trained on experimental heat transfer data of five commercial engine oils. Enhancement intensity, interaction sensitivity, and interaction stability of additive elements are investigated for the range of element concentrations of the experimental dataset.

Abstract Epoxies, synthesized from bisphenol-A (BPA) and epichlorohydrin (ECH), are predominantly used as coatings, adhesives, and matrix material in fiber-reinforced composites for body-in-white (BiW) applications in the automotive sector. However, given the production of conventional epoxies from nonrenewable petroleum resource and toxicity of BPA, several initiatives have been undertaken by researchers to synthesize alternative epoxies from various bio-sources that are free of BPA and exhibit similar mechanical performance. As a result, such bio-sourced epoxies are almost immediately termed as “ecofriendly,” despite the lack of comprehensive evaluation of their ecological performance that takes into account enhanced natural resource usage and associated impacts accompanying such epoxies.