An experimental facility was designed and benchmarked that could simulate the non-uniformities in the flow and thermal fields exiting real gas-turbine combustors. The design of the combustor simulator required analyses of the flow paths within a real combustor in a gas turbine engine. Modifications were made to an existing wind tunnel facility to allow for the installation of the combustor simulator. The overall performance of the simulator was then benchmarked through measurements of velocity, pressure, temperature, and turbulence using a straight exit test section to provide a baseline set of data. Comparisons of the measured quantities were made between two test cases that included a flow field with and without dilution flow.One of the major findings from this study was that the total pressure profiles exiting the combustor simulator in the near-wall region were different from a turbulent boundary layer. This is significant since many studies consider a turbulent boundary layer as the inlet condition to the turbine. Turbulent integral length scales were found to scale well with the dilution hole diameters and no dominant frequencies were observed in the streamwise velocity energy spectra. Dilution flow resulted in an increase in turbulence levels and mixing causing a reduction in the variation of total pressure and velocity. Adiabatic effectiveness levels were significantly reduced for the case with dilution flow in both the near combustor exit region and along the axial length of the straight exit test section. / Master of Science

<P> The design, and construction of a combustion chamber was undertaken, and the basic considerations, design steps and calculations are described. The preliminary testing consisted of measurements of flame temperature, flame tube wall temperature, and flame tube exit plane temperature. A comparison was made between the experimental and theoretical flame temperatures. The uniformity of air flow in the annulus between the flame tube and outer casing was investigated. Tests were made to ascertain the effect of the gas nozzle position on the condition of the combustion gases. </p> / Thesis / Master of Engineering (MEngr)

Apresenta o estado da arte das câmaras de combustão dos motores de combustão interna ciclo Otto à gasolina e a etanol, onde observa de forma qualitativa aspectos evolutivos e específicos ao uso do etanol como combustível alternativo. Propõe sugestões para trabalhos futuros, visando a otimização de uma câmara mais apropriada ao uso deste importante combustível renovável. / It presents the state of the art of combustion chambers of gasoline and ethanol Otto cycle internal combustion engines, where it observes qualitatively evolutive and specific aspects to the use of the ethanol as an alternative fuel. It proposes suggestions for future works, seeking the optimization of a more appropriate combustion chamber for the use of that important renewable fuel.

Abstract The research compares the efficiency of particle removal from exhaust of ritual money burning by an electrostatic precipitator (ESP) and a bag-house filter (BH), both have a capacity of around 30-35 Am3/min. A stainless steel chamber of 0.6 m in diameter and 1.0 m in height was used for the ritual money burning. Combustion gas from the chamber was cooled to 300-400oC by mixing with a certain proportion of ambient air and further cooled to around 100-130oC by a fin tube gas cooler before entering either to the ESP or the BH. Results indicate that TSP in the influent gas could be reduced from 6-392 (average 83) to 1-143 (average 22) mg/Nm3 by the ESP with gas velocities of 5-10 cm/s at 100-120 oC through the spacing between collecting plates. TSP emission factors of 0.0295-9.94 (average ¡Ó standard deviation = 1.81¡Ó2.25) and 0.031-3.36 (average ¡Ó standard deviation = 0.27¡Ó0.26) g/(kg combusted ritual money), respectively, were obtained before and after the ESP filtration. Although the ESP had an initial TSP removal of 80-99%, the performance dropped in a few operation hours because of a fouling of the plate surfaces by the collected fume dusts. Cleaning of the plate surfaces helped in the recovery of the performance, however, it dropped after a few cycles of collection and cleaning. Results from BH tests indicate that TSP in the influent gas to it could be reduced from 9-182 (average 72) to 0-12 (average 2.0) mg/Nm3 with the gas flow through the filter cloth with a velocity of 3.3 cm/s at 120-130 oC which resulted in an initial pressure drop of around 100 mmAq. It was observed that some fine dusts would escape from the cloth fiber spaces when the backwash pulse was operated. It is recommended that the backwash cycle should be minimized and trigged after the gas pressure drop over the cloth reaches up to 300 mmAq. TSP emission factors of 0.0176-1.64 (average ¡Ó standard deviation = 0.52¡Ó0.33) and 0-0.491 (average ¡Ó standard deviation = 0.02¡Ó0.05) g/(kg combusted ritual money), respectively, were obtained before and after the BH filtration. BH filtration is recommended for the TSP control in the ritual money buring. XRD(X-Ray Diffraction) examination of a bottom ash sample indicates that the ash has an elemental composition of O, Na, Al, and Si of 49.9, 11.8, 23.8, and 15.1%, respectively. SEM(Scanning Electron Microscope) analysis indicates that the collected fly ash and the bottom ash have particle sizes of 20-110 (mostly 45-60 nm) and 50-300 (average 250) nm, respectively.

Apresenta o estado da arte das câmaras de combustão dos motores de combustão interna ciclo Otto à gasolina e a etanol, onde observa de forma qualitativa aspectos evolutivos e específicos ao uso do etanol como combustível alternativo. Propõe sugestões para trabalhos futuros, visando a otimização de uma câmara mais apropriada ao uso deste importante combustível renovável. / It presents the state of the art of combustion chambers of gasoline and ethanol Otto cycle internal combustion engines, where it observes qualitatively evolutive and specific aspects to the use of the ethanol as an alternative fuel. It proposes suggestions for future works, seeking the optimization of a more appropriate combustion chamber for the use of that important renewable fuel.

Este trabalho apresenta uma análise comparativa entre diferentes geometrias de câmaras de combustão, no intuito de eleger a que proporcione queima mais adequada de etanol a um motor originalmente projetado para operar no ciclo Diesel que foi transformado para operar no ciclo Otto. O processo de formação de mistura é analisado desde a injeção de combustível no pórtico de admissão até o momento da ignição na câmara de combustão. Esta análise se baseia em simulações 1D e 3D, cujos modelos foram previamente validados em bancada experimental. / This work presents a comparative analysis between different combustion chambers, in order to elect one to provide a more suitable burning ethanol in engine originally designed to operate on diesel cycle which has been converted to operate on Otto cycle. The mixture formation process is analyzed since the port fuel injection until ignition timing in combustion chamber. This analysis is based on 1D and 3D simulations, of which models were previously validated in experimental bench.

Este trabalho apresenta uma análise comparativa entre diferentes geometrias de câmaras de combustão, no intuito de eleger a que proporcione queima mais adequada de etanol a um motor originalmente projetado para operar no ciclo Diesel que foi transformado para operar no ciclo Otto. O processo de formação de mistura é analisado desde a injeção de combustível no pórtico de admissão até o momento da ignição na câmara de combustão. Esta análise se baseia em simulações 1D e 3D, cujos modelos foram previamente validados em bancada experimental. / This work presents a comparative analysis between different combustion chambers, in order to elect one to provide a more suitable burning ethanol in engine originally designed to operate on diesel cycle which has been converted to operate on Otto cycle. The mixture formation process is analyzed since the port fuel injection until ignition timing in combustion chamber. This analysis is based on 1D and 3D simulations, of which models were previously validated in experimental bench.

The Master's thesis deals with the flow of fuel mixture in the combustion chamber and the influence of its geometry on squish generation caused by the compression lift. The thesis introduces design proposals of the geometry of the combustion chamber focusing on the shape of the squish area and their comparison based on the amount of kinetic energy and the velocity profile obtained using 2-D Squish programme calculations.

This master’s thesis describes the design and calculation of the biomass hot water boiler which should be used for heating of office buildings in a collective farm. Fuel composition was determined by recommended literature. Stoichiometric calculations were processed for the fuel composition. The required boiler heat output was determined and compared with the original gas boiler, which was previously used for heating. The thermal calculation of the boiler and the design of the heat exchanger was also performed.

Ce travail de thèse, menée dans le cadre d'une convention CIFRE entre TURBOMECA et le CERFACS, s'inscrit dans un contexte d'amélioration des performances des turbines de type axial équipant les turboréacteurs d'hélicoptère. L'une des principales difficultés rencontrée dans cette démarche concerne la maîtrise de la température que voient les pales de ce composant, notamment la roue haute pression. Les travaux de cette thèse s'articulent autour de deux axes principaux: - Le premier traite l'analyse de la Simulations aux Grandes Echelles (SGE) autour de pales. Une approche numérique SGE sur des maillages non-structurés est comparée aux résultats Reynolds Averaged Navier-Stokes (RANS) sur des maillages structurés, usuels dans ce type de configuration, ainsi qu'à une approche SGE sur maillages structurés. La SGE sur maillage non-structuré démontre sa capacité à prendre en compte les phénomènes qui ont un impact sur les flux de chaleur pariétaux. - Le second axe de recherche a pour objectif de développer un outil numérique de couplage pour assurer le transfert d'information entre un code SGE réactif sur maillage non-structuré, employé dans les chambres de combustion, et un code non-réactif en RANS, utilisé par les industriels pour modéliser l'étage turbine. Cet outil a été validé sur plusieurs cas tests qui montrent le potentiel de cette méthodologie pour le couplage multi-composant. / This PhD dissertation, conducted as part of a CIFRE research project between TURBOMECA and CERFACS, deals with improving performance of axial turbines from helicopter engines. One of the main difficulties with such an objective is the control of the temperature prediction around the blades, especially the temperature of the high pressure rotor. The work of this thesis focusses on two axes: - First concerns the analysis of Large Eddy Simulation (LES) predictions around blades: a numerical LES approach on unstructured meshes is compared to Reynolds Averaged Navier-Stokes (RANS) results on structured meshes as well as to LES on structured meshes. LES on unstructured meshes demonstrates its capacity of taking into account the phenomena which have an impact on wall heat flux around blades. - The second axis deals with the development of a numerical tool for coupling and transferring information between a reactive LES code, used in combustion chambers, and a non-reactive RANS solver, employed by industrial actors for modeling the turbine stage. This tool is validated on a number of test cases which show the potential of this methodology for multi-component predictions.