Stricter emission legislation for heavy trucks in combination with the customers demand on low fuel consumption has resulted in intensive technical development of engines and their control systems. To control all these new solutions it is desirable to have reliable models for important control variables. One of them is the air mass-flow, which is important when controlling the amount of recirculated exhaust gases in the EGR system and to make sure that the air to fuel ratio is correct in the cylinders. The purpose with this thesis was to use system identification theory to develop a model for the air mass-flow through the compressor. First linear black-box models were developed without any knowledge of the physics behind. The collected data was preprocessed to work in the modeling procedure and then models with one or more inputs where built according to the ARX model structure. To further improve the models performance, non-linear regressors was developed from physical relations for the air mass-flow and used to form grey-box models of the air mass-flow.In conclusion, the performance was evaluated through comparing the estimated air mass-flow from the best model with the estimate that an extended Kalman filter together with a physical model produced. / Hårdare utsläppskrav för tunga lastbilar i kombination med kundernas efterfrågan på låg bränsleförbrukning har resulterat i en intensiv utveckling av motorer och deras kontrollsystem. För att kunna styra alla dessa nya lösningar är det nödvändigt att ha tillförlitliga modeller över viktiga kontrollvariabler. En av dessa är luftmassflödet som är viktig när man ska kontrollera den mängd avgaser som återcirkuleras i EGR-systemet och för att se till att kvoten mellan luft och bränsle är korrekt i motorns cylindrar. Syftet med det här examensarbetet var att använda systemidentifiering för att ta fram en modell över luftmassflödet förbi kompressorn. Först togs linjära svartboxmodeller fram utan att ta med någon kunskap om den bakomliggande fysiken. Insamlade data förbehandlades för att passa in i modelleringsproceduren och efter det skapades i enlighet med ARX-modellstrukturen modeller med en eller flera insignaler. För att ytterligare förbättra modellernas prestanda togs icke-linjära regressorer fram med hjälp av fysikaliska relationer för luftmassflödet. Dessa användes sedan för att skapa gråboxmodeller av luftmassflödet. Avslutningsvis utvärderades prestandan genom att det estimerade luftmassflödet från den bästa modellen jämfördes med det estimat som ett utökat kalmanfilter tillsammans med fysikaliska ekvationer genererade.

[pt] A adaptação de um simulador numérico para a simulação da operação bicombustível Diesel-gás em motores com ignição por compressão foi realizada. O código-fonte em questão foi desenvolvido ao longo dos últimos anos pelo IFP, e uma modificação ao modelo da auto-ignição nele contido foi concluída neste estudo. As diversas etapas necessárias para a adaptação são apresentadas. Considerações foram feitas em relação à literatura existente para o assunto, e as hipóteses realizadas foram verificadas numericamente sempre que possível. Uma equação que relaciona os números de octanas do Diesel e do gás natural com a qualidade da auto-ignição de sua combinação resultante é proposta. Foi construída uma extensa base de dados necessária ao funcionamento do modelo, contendo as taxas de reação em função dos parâmetros físicos da mistura. Por fim, foi feita uma análise qualitativa de simulações bicombustível para um motor Diesel. / [en] The adaptation of a numerical simulator for the dual fuel Diesel-gas combustion in compression ignition engines was accomplished. The referred source code has been developed for the past years by the IFP, and a modification of its auto-ignition model was concluded during this study. The various steps needed for this adaptation are presented. All hypotheses were numerically verified when possible. A relation between auto-ignition quality and the combination of the octane numbers of Diesel and natural gas is proposed. A comprehensive reaction rates database required by the model was constructed. Finally, a qualitative analysis of dual fuel simulations in a Diesel engine was conducted.

[pt] Neste trabalho, foi desenvolvida uma modificação do modelo para simulação de sprays Diesel com o método de PDF presumida e cinética química tabulada. Através do acoplamento entre a parte química e a parte turbulenta, avaliou-se os efeitos do spray com a metodologia flamelet. Onde o conceito flamelet trata a chama difusiva e transiente como um conjunto de chamas unidimensionais, utilizando o modelo de PDF presumida para a avaliação dos valores turbulentos. A validação do modelo foi realizada com dados experimentais do laboratório Sandia, em uma câmara a volume constante. A validação e a aplicação do modelo foram conduzidas em diferentes tipos de ensaios experimentais: avaliação e comparação para diferentes modelos de cinética química do n-heptano, validação do método para o modelo de turbulência K-epsilon na câmara de volume constante do Sandia para o n-heptano não reativo, validação e comparação do modelo para o spray reativo e aplicação de modelo para o estudo comprimento do ancoramento de chama e para o tempo de atraso de ignição do n-heptano para diferentes temperaturas ambientes. Em geral, a modelagem proposta tem demonstrado excelente capacidade de previsão para a combustão com spray Diesel numa vasta gama de aplicações e é um candidato altamente promissor para outras aplicações em motores Diesel. / [en] In this work, a modification of the model for the simulation of diesel sprays with the presumed PDF method and tabulated chemical kinetics was developed. Through the coupling between the chemical part and the turbulent part, the effects of the spray were evaluated for the flamelet methodology. Where the textit flamelet concept treats the diffusive and transient flame as a set of one-dimensional flames, using the presumed PDF model for the evaluation of turbulent values. The validation of the model was performed with experimental data from the Sandia laboratory, in a chamber at constant volume. The validation and application of the model were conducted in different types of experimental trials: evaluation and comparison for different chemical kinetics models of n-heptane, validation of the method for the turbulence model K-epsilon in the constant volume chamber of the Sandia for non-reactive n-heptane, validation and comparison of the model for the reactive spray and model application for the study of the flame anchoring length and for the ignition delay time of n-heptane at different ambient temperatures. In general, the proposed modeling has demonstrated excellent predictive capacity for diesel spray combustion in a wide range of applications and is a highly promising candidate for other applications in diesel engines.

Orientador: Pedro Teixeira Lacava / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T16:57:57Z (GMT). No. of bitstreams: 1 Carlos_AndersonAlmeida_M.pdf: 15995318 bytes, checksum: baaba56f9c2c8d35c3ae72468050a525 (MD5) Previous issue date: 2011 / Resumo: Em baixas temperaturas, as condições de partida do motor tornam-se mais difíceis devido a diversos fatores, como por exemplo, a menor lubrificação devido ao aumento da viscosidade do óleo lubrificante, a diminuição da massa de ar e a diminuição das folgas entre as partes móveis do motor como virabrequim, pistão e conseqüentemente o aumento do atrito entre estas partes. Foi construído um dispositivo para estimar o torque resistivo em baixas temperaturas na faixa entre - 20°C a 0ºC em um motor diesel NGD 3,0 litros, quatro cilindros de fabricação da MWM International com o objetivo de estudar a correlação entre o rendimento do motor de partida nestas condições e o torque resistivo solicitado na partida. Este dispositivo permite o levantamento do torque resistivo nos motores diesel sem combustão, onde a lubrificação é mínima e o atrito entre as partes móveis do motor são máximas. Para a medição do torque foi utilizada uma flange de torque modelo T40 de fabricação da HBM acoplada ao dispositivo de arraste, composto por um volante e motor de partida de um motor com 9,3 litros também de fabricação MWM International e o volante do motor que foi testado, através de um eixo cardam. Os testes para o levantamento dos dados foram realizados em um "contêiner" frigorífico utilizado para transportes de cargas perecíveis, como carnes congeladas, adaptado para realização de ensaios de motores diesel a temperaturas negativas (-50ºC + temperatura ambiente) e instalado nas dependências do Centro Tecnológico da MWM International / Abstract: In lower temperatures, the conditions for starting the engine become more difficult due to several factors, eg, less lubrication due to increased viscosity of lubricating oil, the decrease in air mass and reducing the clearances between moving parts the engine crankshaft, piston and consequently increases the friction between these parts. A device was built to estimate the resistive torque at low temperatures in the range between -20°C to 0°C in a diesel engine NGD 3.0-liter four-cylinder manufacturing MWM International aiming to study the correlation between the starter motor efficiency in these conditions and the resistive torque at startup. The device allows the removal of the resistive torque without combustion in diesel engines, where lubrication is minimal and the friction between the moving parts of the engine is maximum. For measuring torque was used a model T40 torque flange from HBM manufacturing device coupled to the drag, comprising a flywheel and starter motor with a 9.3 liters also manufacturing MWM International and the flywheel was tested through a cardan shaft. Tests for the survey data were conducted in a "container" refrigerator used to transport perishable cargo such as frozen meat, suitable for testing diesel freezing temperatures (-50 ° C + ambient temperature) and installed in the premises of the Centre Technological MWM International / Mestrado / Eletrônica / Mestre em Engenharia Automobilistica

Internal combustion engines developments are driven by emissions reduction and energetic efficiency increase. To reach the next standards, downsized/downspeeded engines are required to reduce fuel consumption and CO2 emissions. These techniques place an important demand on the charging system and force the introduction of multistage boosting architectures. With many possible arrangements and large number of parameter to optimize, these architectures present higher complexity than current systems. The objective of this thesis has thus been to investigate the potential of two-stage boosting architectures to establish, for the particular case of passenger car downsized/downspeeded Diesel engines, the most efficient solutions for achieving the forthcoming CO2 emissions targets. To respond to this objective, an exhaustive literature review of all existing solutions has first been performed to determinate the most promising two-stage boosting architectures. Then, a new matching methodology has been defined to optimize the architectures with, on the one hand the development of a new turbine characteristic maps representation allowing straight forward matching calculations and, on the other hand, the development of a complete 0D engine model able to predict, within a reduced computational time, the behavior of any boosting architecture in both steady state and transient operating conditions. Finally, a large parametric study has been carried out to analyze and compare the different architectures on the same base engines, to characterize the impacts of thermo-mechanical limits and turbocharger size on engine performance, and to quantify for different engine development options their potential improvements in term of fuel consumption, maximum power and fun to drive. As main contributions, the thesis provides new modeling tools for efficient matching calculations and synthesizes the main trends in advanced boosting systems to guide future passenger car Diesel engine develop / Varnier ., ON. (2012). Trends and Limits of Two-Stage Boosting Systems for Automotive Diesel Engines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16880 / Palancia

En la actualidad, la industria del transporte es la encargada de satisfacer las necesidades logísticas del mundo. Los combustibles fósiles continúan siendo la principal fuente de energía de esta industria, y el motor Diésel, una de las tecnologías principales en la transformación de la energía química de estos combustibles en energía mecánica a través del proceso de combustión. Asociado a este proceso de transformación de la energía, un conjunto de efectos indeseados como las emisiones contaminantes o los gases de efecto invernadero han hecho movilizar a la comunidad científica. Dicha comunidad, ha realizado importantes esfuerzos en la investigación de soluciones limpias y eficientes que ayuden a minimizar los efectos indeseados del uso del motor Diésel. Sumado a los esfuerzos en la investigación, diferentes organizaciones gubernamentales han generado normativas que regulan estas emisiones contaminantes y la industria del motor ha reaccionado integrando soluciones tecnológicas que han hecho evolucionar la configuración original del motor Diésel. Debido a razones principalmente geopolíticas, el desarrollo económico a nivel mundial no se ha dado de manera homogénea, y en la actualidad, existe una disparidad global en cuanto a las exigencias en normativa de emisiones y la implementación de tecnologías para su control, siendo estas afectadas principalmente por sus costos. Es en este contexto donde se enmarca esta tesis doctoral, cuyo objetivo principal es el estudio de diferentes estrategias de inyección y de renovación de la carga como herramienta de control de emisiones en motores de encendido por compresión, teniendo en cuenta el costo de su integración. Se busca poder definir los límites de estas estrategias de bajo costo, determinando así su potencial real en la futura normativa de los mercados emergentes. Para abordar dicho objetivo, la tesis se ha desarrollado en tres etapas. En la primera, se ha realizado una aproximación teórico-experimental a las estrategias de inyección mediante modelado 3D-CFD y ensayos paramétricos en motor que permiten establecer como los parámetros de inyección responden al objetivo planteado. En la segunda etapa, se han estudiado las estrategias de renovación de la carga. Primero desde el modelado 1D para luego su posterior evaluación mediante su ensayo experimental en motor definiendo de esta manera las ventajas e inconvenientes de cada estrategia. En la tercera y última etapa, se han combinado todas las estrategias previamente estudiadas desde una aproximación experimental. De esta manera se puede alcanzar el objetivo de la tesis doctoral donde se ha comprobado la viabilidad de estas estrategias de bajo costo y se ha determinado su verdadero potencial como herramientas de control de las emisiones contaminantes. / En l'actualitat, la indústria del transport és l'encarregada de satisfer les necessitats logístiques del món. Els combustibles fòssils continuen sent la principal font d'energia d'aquesta indústria, i el motor Diésel, una de les tecnologies principals en la transformació de l'energia química d'aquests combustibles en energia mecànica a través del procés de combustió. Associat a aquest procés de transformació de l'energia, un conjunt d'efectes indesitjats com les emissions contaminants o els gasos d'efecte hivernacle han fet mobilitzar a la comunitat científica. Aquesta comunitat, ha realitzat importants esforços en la recerca de solucions netes i eficients que ajuden a minimitzar els efectes indesitjats de l'ús del motor Diésel. Sumat als esforços en la recerca, diferents organitzacions governamentals han generat normatives que regulen aquestes emissions contaminants i la indústria del motor ha reaccionat integrant solucions tecnològiques que han fet evolucionar la configuració original del motor Diésel. A causa de raons principalment geopolítiques, el desenvolupament econòmic a nivell mundial no s'ha donat de manera homogènia, i en l'actualitat, existeix una disparitat global quant a les exigències en normativa d'emissions i la implementació de tecnologies per al seu control, sent aquestes afectades principalment pels seus costos. És en aquest context on s'emmarca aquesta tesi doctoral, que el seu objectiu principal és l'estudi de diferents estratègies d'injecció i de renovació de la càrrega com a eina de control d'emissions en motors d'encès per compressió, tenint en compte el cost de la seua integració. Se cerca poder definir els límits d'aquestes estratègies de baix cost, determinant així el seu potencial real en la futura normativa dels mercats emergents. Per a abordar dita objectiva, la tesi s'ha desenvolupat en tres etapes. En la primera, s'ha realitzat una aproximació teòric-experimental a les estratègies d'injecció mitjançant modelatge 3D-CFD i assajos paramètrics en motor que permeten establir com els paràmetres d'injecció responen a l'objectiu plantejat. En la segona etapa, s'han estudiat les estratègies de renovació de la càrrega. Primer des del modelatge 1D per a després la seua posterior avaluació mitjançant el seu assaig experimental en motor definint d'aquesta manera els avantatges i inconvenients de cada estratègia. En la tercera i última etapa, s'han combinat totes les estratègies prèviament estudiades des d'una aproximació experimental. D'aquesta manera es pot aconseguir l'objectiu de la tesi doctoral on s'ha comprovat la viabilitat d'aquestes estratègies de baix cost i s'ha determinat el seu vertader potencial com a eines de control de les emissions contaminants. / Nowadays, the transport industry is responsible for accomplish the world's logistics requirements. Fossil fuels continue to be the main source of energy for this industry, and the Diesel engine, one of the main technologies in the transformation of the chemical energy of these fuels into mechanical energy through combustion. Associated with this process of energy transformation, a set of undesired effects such as pollutant emissions or greenhouse gases have challenged the scientific community that has made significant research efforts aiming clean and efficient solutions. Added to the scientific community efforts, different governmental organizations have created regulations in order to control these pollutant emissions and the engine industry has reacted by integrating technological solutions that have evolved the original configuration of the Diesel engine. Due mainly to geopolitical reasons, economic development worldwide has not occurred in a homogeneous manner, and currently, there is a global disparity regarding the requirements in emission regulations and the implementation of technologies for their control, mainly driven by their costs. It is in this framework where is set this doctoral thesis, with the main objective to study different injection and air management strategies as a tool for emission control in compression ignition engines, taking into account the cost of their integration. The aim is to be able to define the limits of these low-cost strategies, thus determining their real potential in the future regulations of emerging markets. To address this objective, the thesis has been developed in three stages. In the first one, a theoretical-experimental approach to the injection strategies has been carried out using 3D-CFD modeling and parametric engine tests which allow us to establish how the injection parameters help to reach the depicted thesis objective. In the second stage, the air management strategies have been studied. First, from the 1D modeling point of view in order to select the best option for this platform, and later to proceed with the experimental validation of this selection. Through the described approach is possible defining the advantages and disadvantages of each air management strategy. In the third and final stage, all previously studied strategies have been combined from an experimental approach. In this way, the evaluation of these cost-effective strategies has been defined and the fully potential as a tool for emissions control has been determined thus the objective of the doctoral thesis could be achieved. / Estepa Ruiz, D. (2018). Study of different fuel injection and air management strategies as a tool for emissions control in a compression ignition engine (Diesel engine) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/113076 / TESIS

This thesis deals with the numerical analysis state of stress diesel engine piston. Based on results of performed analyses a new pistons designed with a focus on mass reduction and consequently individual structural designs are compared with present piston.

Thesis Remotorization of the aircraft EV-55 Outback deals with possibility of installationt piston diesel engine instead of turboprop engine PT6A-21. Begining of this thesis deals with choice of convenient engine and propeller. Then, 3D model of engine bed is designed, followed by mass analysis. Based on results from the mass analysis and requirements from the CS - 23 regulation, load is specified and stress analysis is done. The other part of this thesis deals with adjustment of the airframe and with calculation of flight performances. Finally, economic indices are specified.

In the introduction this thesis brings a short summary of the energy, environmental and economical balance, related to the production and use of conventional fuels for diesel engines, and compares them with possibility of using recycled cooking vegetable oils as a fuel. The main part focuses on the laboratory analysis of major physical and chemical properties of this alternative fuel and on their comparison to diesel fuel, especially according to ČSN EN 590 norm. In conclusion there is a proposal of diesel vehicle modification to be propelled with waste vegetable oils.

The goal of this master’s thesis is to examine the influence of eccentricity on the behaviour of forces between the piston and cylinder liner and on balancing of the crank mechanism for given parameters of the diesel engine. Another aim of this paper is to propose an appropriate balancing of the crank mechanism followed by stress analysis considering torsional vibration for a chosen value of eccentricity.