Analytical and chemometric applications in the study of automotive and related lubricant degradation

Chemometric techniques have been utilised for the study of automotive lubricant oil degradation. The initial investigations were performed by analysis of data from top ring zone engine test datasets. Principal component analysis (peA) was used to explore the ring zone data. The difference in the performance of various lubricant formulations sampled from the ring zone region of operating Petter AA-I diesel and Petter W-1 petrol engines was established by the partial least squares discriminant model (PLS-DA). The results from the study of the test engine data provided optimised insight into the break down of the chemical/physical parameters of the lubricants during operative conditions. This work proceeded onto condition monitoring techniques. Over a hundred used oil samples were obtained from the sump of various petrol and diesel engine vehicles, in addition fresh oil samples were also collected. Series sets of used oil samples were acquired by periodic sampling from a Honda 1.8 L petrol engine, a Peugeot 1.9 L diesel engine and a diesel engine sump test. Following sample acquisition, each oil sample was analysed using FTIRIATR and conductimetric titrations were performed. These analytical equipments are used to monitor and assess the extent of degradation. A novel model was developed to enhance the IP 400 conductimetric titration method of measuring base number of new and used lubricants. This nonlinear least-squares model was integrated into the titration programme along with two linear least-squares curve fitting methods. The models were effectively used to estimate the titration endpoint which was subsequently used in base number calculation. The results demonstrated the robustness of the three endpoint estimation methods and indicate reliability of the titration equipment and programme. peA was used to analyse the FTIR spectra data of the oil samples. peA performed on different sets of pre-processed data uncovered objective information on the condition of the lubricants. peA models of the series set oil samples highlighted difference between samples as a result of progressive degradation. The effect of adding fresh oil (top-up) to the engine was apparent. This work has demonstrated the importance and efficiency of mathematical/statistical models in lubricant oil engine testing and condition monitoring

Aeronautical Engineering: A special bibliography with indexes, supplement 74

This special bibliography lists 295 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1976

In-cylinder fuel and lubricant effects on gasoline engine friction

The purpose of the research reported in this thesis was to investigate the viability and quantify the potential gains of improving fuel economy of the gasoline engine through strategic application of additives. An increased awareness of the link between greenhouse gas emissions and global warming means that there is a desire to reduce carbon dioxide emissions from transportation. There is therefore a growing emphasis on improving the fuel economy performance of vehicles. The addition of friction modifier additives to the fuel is one way to achieve this. Using bespoke in-cylinder sampling techniques, an understanding of the operation of the piston assembly, a system responsible for much of the power loss in the internal combustion engine, is developed. Validation is given to the hypothesis that fuel economy gains can be achieved through the application of friction modifier administered to the engine via the gasoline. Results show gasoline administered friction modifier additive can accumulate in the piston assembly lubricant at levels 77 times greater than the initial fuel treatment level. The performance of a large number of friction modifier additives were uniquely screened in a novel bench-top test which simulated the arduous in-cylinder conditions found in a firing gasoline engine. The test generated vast amounts of information which led to high performance formulations capable of reducing the friction coefficient in both the boundary and mixed lubrication regimes by around 50% when compared with the result for the base oil alone. Surface analysis techniques were also employed 0!l engineering surfaces coated with friction modifier additives and add to the knowledge of their mechanism of action. Finally a series of engine tests were conducted which prove the effectiveness of friction modifier administered to the engine via the gasoline. A fuel economy improvement of approximately 2% was seen where friction modifier gasoline was employed. Application of successful technology such as this is shown to correspond to the projected saving of around 502 million litres of gasoline and 388,000 tonnes of carbon (C02) per year in the UK alone

Electrochemical Behavior of AISI 1020 Steel in Type C Commercial Gasolines

In the present paper, the corrosion behavior of 1020 carbon steel in commercial gasoline-ethanol blends was investigated. The composition of each gasoline-ethanol blend was evaluated by infrared spectroscopy, and the ethanol content was determined by the ABNT 13992 reference method. Electrochemical Impedance Spectroscopy (EIS) and polarization methods were employed to evaluate corrosion resistance and penetration rates. Statistical analyses revealed that the gasoline’s solution resistance governs the corrosion process, the RON (Research Octane Number) and MON (Motor Octane Number) numbers as well as the olefin content being more related to the corrosion rates. The polarization resistance had minor impact on the corrosion process. This work is licensed under a Creative Commons Attribution 4.0 International License

On-Line Monitoring of Engine Health Through the Analysis of Contaminants in Engine Lubricant

Monitoring automobile liquids, such as engine lubricants, has received increasing attention recently mainly due to environmental and safety legislation, coat saving measures, and customer demand. Literature review in monitoring engine lubricant condition indicates systems approach, an intellectual discipline method to address complex problem, has never been used to monitor engine performance and health through the engine sub-systems such as lubricant system. The literature review also points toward deficiency in considering lubricant as a source of information for engine performance evaluation, and lack of understanding of engine lubricant as a medium with random properties. Engine lubricant condition reflects the state of health of engine through its properties. Recognition and analysis of the correlation between engine lubricant system based on the lubricant properties and engine performance is crucial to provide insight into engine health. The contribution of this research will be implementation of systems approach to monitor engine performance through engine lubricant using new methodologies of surface plasmon resonance, object shape based optical analysis and statistical optical analysis methodologies to monitor optical properties of lubricant with respect to aging process and contaminants in real time and on-line. Degradation of engine lubricant causes variation in the optical properties of lubricant such as refractive index, absorption, statistical optical characteristics, shape parameters and etc. The purpose of using surface plasmon resonance (SPR) is to study the change in the reflectivity and incidence angle caused by variation in the refractive index and absorption of lubricant due to its degradation and presence of contaminants. Utilization of SPR measurement for characterization of engine lubricant will develop new knowledge which can be used for on-line condition monitoring of lubricant quality. To investigate the variation in statistical optical characteristics of lubricant, this research also introduces two new methodologies. Statistical optic and object shape-based methodologies are based on the optical analysis of the distortion effect when an object image is obtained through a thin random medium. In the object shape-based optical analysis, several parameters of an acquired object image are measured and compared. In the statistical optic analysis methodology, statistical auto and cross-characteristics are used for the analysis of combined object-lubricant images. Both proposed methodologies utilize the comparison of measured and calculated parameters for fresh and contaminated lubricants. Proposed methodologies are verified experimentally showing ability to distinguish lubricant with different contamination individually and in a combined form. Capabilities of the proposed methodologies are extended to establish the linkage between accumulated travelled distance and the change in the optical statistical properties of the lubricant. Also, on board analysis to detect the presence of coolant, gasoline and water (1%-5%) are performed

Progettazione e Analisi di Dispositivi di Riscaldamento Attivo per Ridurre le Emissioni Inquinanti da Avviamento a Freddo di Motori a Combustione interna a Benzina

La crescente preoccupazione ambientale in molti paesi del mondo, ha spinto le istituzioni a introdurre legislazioni sempre più restrittive sulle emissioni inquinanti nel settore automobilistico. Ciò ha portato a una progressiva revisione dei limiti sulle emissioni e, allo stesso tempo, delle procedure di test. L'ottimizzazione della combustione del motore, sebbene fondamentale per ridurre le emissioni in uscita dal motore, non è sufficiente per rispettare tali limiti; sono necessarie efficienze di conversione molto elevate da parte dei dispositivi di post-trattamento dei gas di scarico fin dall'avvio del motore. La ricerca condotta in questo studio, riguarda la definizione e l’analisi di dispositivi di riscaldamento attivo, per migliorare le prestazioni dei sistemi di post-trattamento dei gas di scarico, in particolare durante la fase critica di avviamento a freddo. Questa fase è essenziale per il controllo delle emissioni, difatti, l'efficienza del sistema di post-trattamento si riduce significativamente quando il motore e il sistema di scarico sono freddi. Lo studio si è concentrato su due tecnologie principali: il bruciatore di combustibile e il catalizzatore riscaldato elettricamente (EHC), entrambi testati e analizzati attraverso una combinazione di simulazioni numeriche e test sperimentali. Il bruciatore di combustibile, un dispositivo progettato per introdurre una fiamma controllata direttamente all’interno della linea di scarico (al fine di aumentare rapidamente la temperatura del post-trattamento), è stato in una prima fase valutato attraverso simulazioni numeriche. Queste simulazioni (condotte in ambiente sia 1D che 3D) sono servite per prevedere il comportamento del bruciatore in diverse condizioni di utilizzo. La geometria della connessione tra il bruciatore e la linea di scarico è stata anch’essa ottimizzata mediante simulazioni per garantire un efficiente trasferimento di calore dal bruciatore al post-trattamento dei gas di scarico. Inoltre, le simulazioni hanno permesso di investigare gli effetti della variazione della durata del preriscaldamento (quanto tempo il bruciatore è in funzione prima dell'avvio del motore) sulle emissioni allo scarico Per validare queste simulazioni, sono state condotte prove sperimentali su un prototipo di bruciatore. Il funzionamento del bruciatore è stato ottimizzato per ottenere un avviamento ripetibile, minimizzare le emissioni durante il funzionamento del bruciatore stesso (emissioni del bruciatore) e massimizzare l'output termico diretto verso il post-trattamento. I risultati di questi esperimenti hanno dimostrato che il bruciatore può ridurre significativamente le emissioni allo scarico rispetto a strategie di riscaldamento passivo. Parallelamente all'indagine sul bruciatore, la ricerca si è concentrata anche sull'EHC, che utilizza energia elettrica per riscaldare il post-trattamento dei gas di scarico. Analogamente al bruciatore, l'EHC è stato valutato mediante simulazioni CFD sia 1D che 3D. Queste simulazioni hanno permesso di prevedere quanto efficacemente l'EHC po aumentare la temperatura del sistema di post-trattamento fino ad arrivare alla sua temperatura di attivazione. I modelli hanno preso in considerazione vari fattori, come ad esempio l'energia e la potenza elettrica impiegate. A seguito delle simulazioni, è stata condotta una campagna sperimentale dedicata. Gli esperimenti hanno convalidato l'accuratezza dei modelli di simulazione e hanno fornito dati reali sulle prestazioni dell'EHC. Inoltre, sono state studiate diverse strategie di preriscaldamento per l'EHC, analizzando come l'attivazione del dispositivo prima dell'avvio del motore influenzasse l'efficienza complessiva del sistema di post-trattamento. La ricerca ha dimostrato che l'EHC può migliorare la conversione degli inquinanti durante le fasi iniziali di avviamento a freddo, superando in efficacia le strategie di riscaldamento passivo del catalizzatore.In the last two decades, the increasing environmental concern in many countries worldwide has pushed the regulators to introduce more and more restrictive legislation on pollutant emissions for the automotive sector. This has led to a progressive revision of the emission limits and, at the same time, of the testing procedures. Under these challenging boundary conditions, engine combustion optimization, although fundamental to lower specific engine-out emissions, is not enough; very high after-treatment conversion efficiencies from the engine start-up onwards are necessary. The research undertaken in this work was a systematic exploration of the potential of active heating devices to improve the performance of exhaust after-treatment systems, particularly during the critical light-off phase. This phase is essential for emissions control, as the efficiency of the after-treatment system is significantly reduced when the engine and exhaust system are cold. The study focused on two main technologies: the fuel burner and the electrically heated catalyst (EHC), both of which were tested and analyzed through a combination of numerical simulations and experimental validation. The fuel burner, a device designed to introduce a controlled flame directly into the exhaust line to rapidly increase the after-treatment temperature, was first assessed through numerical simulations. These simulations were crucial in predicting how the burner would perform under various conditions and were conducted in both 1D and 3D CFD configurations to provide a comprehensive understanding of its operation. The geometry of the connection between the burner and the exhaust line was also optimized by means of simulations to ensure efficient heat transfer and minimal heat loss. Moreover, the simulations allowed to investigate the effects of varying the pre-heating duration (how long the burner operated before the engine was started) on the tail pipe emissions output. To validate these simulations, experimental trials were conducted on a prototype fuel burner. The fuel burner operation was optimized to achieve a repeatable start-up, to minimize emissions during the burner operation (burner-out emissions), and to maximize the thermal output. The results from these experiments were crucial, demonstrating that the fuel burner could significantly reduce the cumulative tailpipe emissions when compared to passive heating strategies. Parallel to the fuel burner investigation, the research also concentrated on the EHC, which uses electrical energy to heat the after-treatment. Similar to the fuel burner, the EHC was evaluated using both 1D and 3D CFD simulations. These simulations were designed to predict how effectively the EHC could raise the temperature of the after-treatment system to its light-off temperature. The models took into account various factors, such as the electrical energy and power input, and the heat transfer characteristics of the after-treatment system. Following the simulations, a dedicated experimental campaign took place. The experiments were critical for two main reasons: they validated the accuracy of the simulation models and provided real-world data on the performance of the EHC. Moreover, pre-heating strategies for the EHC were investigated, analyzing how activating the device before the engine start-up affected the overall efficiency of the after-treatment system. The research demonstrated that EHC could improve the conversion of pollutants during the initial cold start phases, outperforming passive catalyst heating strategies. The comparative analysis between the fuel burner and the EHC highlighted that both technologies could significantly reduce cumulative tailpipe gaseous emissions during engine cold starts

Chemical characterisation and classification of forensic trace evidence

Automotive paint, in the form of paint chips and/or smears, is one of the most commonly encountered forms of forensic trace evidence located at automotive related incidents. There is an increasing demand for more scientifically rigorous approaches to the interpretation of such evidence. This dissertation presents studies examining the use of a suite of spectroscopic techniques in conjunction with multivariate statistics, in order to develop analytical and interpretational protocols for automotive paint evidence