In this study, an ignition unit was designed and constructed for a new design engine with eight cylinders and sixteen pistons. The ignition coils with two high voltage outputs were used to ignite sixteen spark plugs on the system. They were driven by PIC16F628A based igniter circuits triggered with digital signals. The igniter circuits receive ignition signals in a square wave form from a main control circuit / they open or close primary voltage of the induction coils to ignite spark plugs. This main control circuit is based on PIC16F877A / and there are two of them. The duty of main control circuit is to determine ignition advance according to engine speed and cooling water temperature, and send proper ignition signals to the igniter circuits. This main control circuit receives engine speed from the other main circuit (secondary control circuit) with serial communication and reads cooling water temperature and then it reads advance value from external eeprom memory according to engine speed and temperature. The main control circuit receives cylinder position signals from the secondary control circuit and adds advance value on them to form ignition timing signals which triggers igniter circuits. The secondary control circuit reads engine speed and determines cylinder positions with two magnetic pick-ups and LM2907 circuits on a gear wheel. This gear wheel was used to simulate disks on the crank shaft of the cars, and driven with an electric motor. The ignition unit was tested for different engine speeds, and its proper working was proved.

A detailed multi-zone thermodynamic simulation has been developed for the direct-injection (DI) diesel engine combustion process. For the purpose of predicting heterogeneous type combustion systems, the model explores the formation of pre-ignition radicals, start of combustion, and eventual heat release. These mechanisms are described based on the current understanding and knowledge of the diesel engine combustion acquired through advanced laser-based diagnostics. Six zones are developed to take into account the surrounding bulk gas, liquid- and vapor-phase fuel, pre-ignition mixing, fuel-rich combustion products as well as the diffusion flame combustion products. A three-step phenomenological soot model and a nitric oxide emission model are applied based on where and when each of these reactions mainly occurs within the diesel fuel jet evolution process. The simulation is completed for a 4.5 liter, inline four-cylinder diesel engine for a range of operating conditions. Specifically, the engine possesses a compression ratio of 16.6, and has a bore and stroke of 106 and 127 mm. The results suggest that the simulation is able to accurately reproduce the fuel jet evolution and heat release process for conventional diesel engine combustion conditions. The soot and nitric oxide models are able to qualitatively predict the effects of various engine parameters on the engine-out emissions. In particular, the detailed thermodynamics and characteristics with respect to the combustion and emission formation processes are investigated for different engine speed/loads, injection pressures and timings, and EGR levels. The local thermodynamic properties and energy, mass distributions obtained from the simulation offer some fundamental insights into heterogeneous type combustion systems. The current work provides opportunities to better study and understand the diesel engine combustion and emission formation mechanisms for conventional diesel engine combustion modes. The flexible, low computational cost features of this simulation result in a convenient tool for conducting parametric studies, and benefits for engine control and diagnostics.

Due to the kinematic limitation of slider-crank mechanisms used in traditional internal combustion engines, such devices driven by their piston motions have a difficulty to reach the better fuel efficiency. In order to make the fuel efficiency better, many engine mechanisms that can be tuned to obtain desired piston motions have been proposed. Since most of the proposed engine mechanisms have complex linkages and bulky size, they become impractical for real applications. The design of a conjugate cam engine mechanism containing a conjugate cam with a slider crank mechanism can be conveniently tuned to produce a desired piston motion in consideration of a limited space, weight, and the number of linkages. The aim of this research is to set up a systematic design and analysis procedure for conjugate cam engine mechanisms. First of all, the kinematic analysis of conjugate cam engine mechanisms is performed based on the rigid body transformation method to determinate the conjugate cam profiles. Then, the geometric properties including the pressure angle and radius of curvature are investigated. Also, in order to characterize the rigid body dynamic behavior of the mechanism, the Newton¡¦s Law is used to derive equations of motion. Finally, it is conducted to design and analyze a real system, and observe the real condition from the experiment to prove the theory is correct.

A poly-generation system can be defined as the simultaneous and collocated generation of two or more energy supply types, aimed to maximize the utilization of the thermodynamic potential (efficiency) of the consumed energy resources. A Polygeneration system may involve co-generation (power and heat) or tri-generation (power, heat, and cold) processes and may also be connected to a district energy system. A poly-generation plant reclaims heat in a useful form that would be wasted otherwise in separate electricity and heat (and chilled water in some cases) generating systems. By this way a poly-generation plant provides a variety of benefits including improved efficiency and fuel savings, reduction of the primary energy demand total cost of utility service and unit fuel cost, independency for energy and protection of environment. With the overall efficiencies in the range of 70-90%, poly-generation systems are gaining popularity all around the world. including Turkey. In spite of all their potential benefits and increasing interest for poly-generation systems, there is not yet any rating, testing, metrication and classification guidelines and standards. It is indeed very important to rate the performance and energy savings potential, determine the heat and power outputs, estimate the system efficiency and the ratio of the split of the power produced between thermal and electric. These are the information which are hard to determine since there are not enough common test standards, rating standards and nor consensus-based terminology for combined heat and power systems in the world literature. Even the classification of the cogeneration systems is hardly globalized. Aim of this study is to develop a common procedure with respect to the above shortcomings for testing and rating poly-generation systems under realistic operating conditions with accurate formulae which will help to contribute energy and exergy economy by establishing a robust metrication standard based on new evaluation parameters. This study aims to find a procedure to evaluate a poly-generation system by establishing standard test methods and evaluation tools in terms of parameters like energy and exergy characteristics of thermal and electric loads, temperature demand and power split for determining operational characteristics of the system. This may be achieved by revising and expanding DIRECTIVE 2004/8/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL. A case study is expected to be based on a trigeneration power plant to be received within the framework of the EU FP6 HEGEL Poly-generation project, to be tested at METU, which has a capacity of 145 kW electric and 160 kW useful heat.

Bakalauro darbą „Brauno dujų panaudojimo vidaus degimo variklyje galimybių tyrimas. Ekologinis aspektas“ sudaro įvadas, trys skyriai, išvados, literatūros sąrašas ir priedai. Šio darbo apimtis 51 puslapis. Darbe yra 18 paveikslėliai ir 1 lentelė. Įvade iškeliama darbo problema, tikslai, uţdaviniai bei temos aktualumas. Pirmajame skyriuje pateikiama informacinių šaltinių analizė. Antrajame skyriuje detaliai aprašoma eksperimento metodika. Trečiajame skyriuje pateikti dvitakčio vidaus degimo variklio dirbusio prie skirtingų Brauno dujų kiekio eksperimentinių tyrimų rezultatai ir jų analizė. / The Bachelor„s thesis “The research of appliance of Brown gas in internal - combustion engine. The ecological aspect” consists of introduction, three chapters, conclusions, literature source and additions. The volume of this work is 51 pages. There are 18 pictures and 1 table in this work. The introduction sets the problem, the aims, the goals of the study and relevance of the topic. The first chapter provides an analysis of information sources. The second chapter describes in detail the experimental technique. The third chapter provides the results of the two-stroke internal combustion engine, which has been employed at different Brownian gas experimental research and their analysis.

Bakalauro baigiamąjį darbą „Brauno dujų panaudojimo vidaus degimo variklyje galimybių tyrimas. Energetinis aspektas“ sudaro 6 skyriai. Darbo apimtį sudaro 36 puslapiai, 19 paveikslėlių, 3 lentelės ir priedai. Įvade iškeliama darbo problema, tikslai ir uždaviniai. Pirmajame skyriuje pateiktas dvitakčio vidaus degimo variklio veikimas, aptariami naudojami degalai. Antrajame skyriuje analizuojamas elektrolizės procesas vykstantis Brauno dujų generatoriuje. Trečiajame skyriuje analizuojamas vandenilio panaudojimas vidaus degimo varikliuose ir vandenilio kaip kuro savybės. Ketvirtame skyriuje aptariamos kylančios problemos ir aktualijos. Penktame skyriuje aprašoma tyrimo metodika. Darbo pabaigoje pateikiame išvadas, kurias padarėme atlikę eksperimentą. / The final Bachelor's work " The research of appliance of Brown gas in internal - combustion engine. Power and energy aspect “ consists of six chapters. The work is made of 36 pages, 19 drawings, 3 tables and accessories. Problem of the research along with objectives and goals are provided in the introduction. The first chapter contains a two-stroke internal combustion engine operation and fuel it is using. The second chapter analyzes the electrolysis process at Brown gas generator. The third chapter examines the use of hydrogen in the internal combustion engines and hydrogen as the fuel properties. The fourth chapter deals with emerging issues and news. The fifth chapter describes the research methodology. At the end of work we made conclusions, which we notice doing the experiment.

AN ABSTRACT OF THE THESIS OF AMIT SHRESTHA, for the Master of Science degree in MECHANICAL ENGINEERING, presented on July 6th 2009, at the Southern Illinois University at Carbondale. TITLE: DEVELOPMENT AND PERFORMANCE EVALUATION OF A MONO-VALVE ENGINE MAJOR PROFESSOR: Dr. Suri Rajan A new Mono-Valve engine head was fabricated and assembled for a standard 4-stroke single cylinder Two-Valve gasoline engine with an aim to achieve an improved air flow characteristics than that of the Two-Valve engine. The Mono-Valve engine has only one valve in the cylinder head with the intake and exhaust ports controlled by an auxiliary Rotary-Valve. The two engines were tested under cold flow motoring conditions at engine speeds ranging from 1000 to 2500 rpm under fully open and half open throttle conditions in order to study and compare their volumetric efficiencies. Variable intake pipe lengths of 8.25, 25.5 and 39 inches were used to study their effect on volumetric efficiencies and in-cylinder pressure characteristics of both the engines. The results of the experiments showed that the average in-cylinder peak pressure, intake and exhaust pressures characteristics are similar for both the engine heads. However, the volumetric efficiency of the new Mono-Valve engine head was found to be 2-7% less than that of the original Two-Valve engine head depending upon the length of the intake pipe. This is mainly due to the opening angle in the Rotary-Valve that mostly controls the duration of the intake and the exhaust processes, and also due to the timing of the opening and closing of the intake and exhaust ports.

Este trabalho aborda o desenvolvimento de um sistema de controle em malha fechada de torque e velocidade de rotação para testes de motores de combustão interna em uma bancada que possui um dinamômetro de correntes de Foucault. É apresentada uma revisão bibliográfica que abrange a fundamentação teórica básica sobre dinamômetro, alguns dos principais testes realizados em motores de combustão interna e técnicas de controle e instrumentação que estão sendo desenvolvidas por pesquisadores sobre o tema de controle de dinamômetro para testes de motores de combustão interna. O projeto surgiu com a necessidade do Laboratório de Motores da UFRGS realizar vários testes em motores a combustão tendo uma maior confiabilidade e rapidez para aquisição dos resultados. Este sistema está baseado num microcontrolador da família Atmega onde foram implementados os algoritmos de um controlador PID e um proporcional, que controlam respectivamente, os níveis de corrente contínua aplicadas no dinamômetro e o percentual de abertura da borboleta do motor combustão através de um motor de passo. A etapa de controle é executada no microcontrolador e uma interface gráfica foi implementada em Labview. Esta interface gráfica faz a leitura via porta serial dos dados do microcontrolador e traça suas curvas as salvando em arquivo, também se pode visualizar os sinais das temperaturas do motor e dinamômetro e nível de combustível do reservatório. A validação do controle desenvolvido foi comprovada através da verificação da convergência dos sinais para os valores de referência desejados. O controle propiciou também uma diminuição dos tempos para obtenção das respostas desejadas em comparação com o sistema anterior de controle manual. / This paper describes the development of a torque and rotation speed closed loop control system for internal combustion engine tests in a bench using a Foucault current dynamometer. A bibliographical review that encompasses basic dynamometer theoretical concepts, some of the most important tests applied to internal combustion engines, and control and instrumentation techniques currently under development on dynamometer testing for internal combustion engines is presented. This project needs to perform tests in combustion engines which would produce more dependable and faster results. The system herein developed is based on an Atmega-type microcontroller where algorithms of both a PID and a proportion controller, controlling respectively the levels of direct current applied through the dynamometer coils and the opening of an internal combustion engine throttle body by means of a step motor, were implemented. The control stage was done in the microcontroller and a graphic interface for a personal computer was created in Labview. This graphic interface facilitates the microcontroller data reading and traces its curves, saving them in a file; also, the engine and dynamometer temperature signals and the tank fuel level can be visualized. The validation of this control has been proved by the signal convergence check for desired reference values. Furthermore, the control has enabled a reduction in ideal answer time attainment as compared to the previous manual system.

This thesis "The influence of composition on biomass energy conversion efficiency in the gas combustion engine" deals with the matter of obtaining energy from biomass to propel engines. It describes the historical development and use of the wood gas treatment process for its production of biomass from the beginning of this discovery up to the use and large scale implementation around the world. The last section presents several experiments with different types of biomass and an experiment to determine the energy obtained in a simple gas combustion engine. Construction of a prototype is part of this thesis.

[pt] Estudou-se a aplicação de nanofluidos no sistema de arrefecimento de motores a combustão interna. Nanofluidos são suspensões de partículas de diâmetro menor que 100 nm em fluidos convencionais de troca de calor, tais como água, óleo, etileno glicol, entre outros. Devido às suas características favoráveis de transferência de calor, em função da suspensão de partículas, metálicas ou não metálicas, com elevada condutividade térmica, nanofluidos têm sido considerados para atuar como fluidos térmicos em diferentes aplicações. Desenvolveram-se modelos matemáticos para operação em regime permanente, na avaliação do efeito das características térmicas e hidráulicas do escoamento do nanofluido nos componentes do sistema de arrefecimento; e em regime transiente, na avaliação do processo de aquecimento do motor. Fez-se uso do pacote EES para a simulação e consideraram-se os seguintes componentes do sistema de arrefecimento automotivo: radiador, camisas do bloco de cilindros, termostato e bomba do líquido de arrefecimento. Foram empregados o método dos parâmetros concentrados e o método (épsilon)-NTU para a modelagem global do sistema monofásico. Diferentes tipos de nanofluidos, com variações na concentração volumétrica de nanopartículas, foram considerados na avaliação desta alternativa em fluidos térmicos visando aplicações automotivas. / [en] The application of nanofluids in cooling systems of internal combustion engines was studied. Nanofluids consist of nanoparticles (with dimension below 100 (u)m) suspended in traditional heat transfer fluids, such as water or ethylene glycol. Given their favourable heat transfer characteristics, because of the suspension of high thermal conductivity particles, metallic or non-metallic, nanofluids have been considered as potential substitutes for conventional heat transfer fluids. Mathematical models were developed for steady-state operation, for the evaluation of thermal and hydraulic behavior of the cooling system, and for transient regime, for the assessment of the engine start-up process. The EES software was employed for the simulation. The following components of the cooling system were considered: radiator, engine cooling jackets, thermostat and coolant pump. Lumped parameter analysis and the effectiveness- NTU method were used for the single-phase system simulation. Different types of nanofluids, with variation on the volume fraction, were considered in this study.