Master of Science / Department of Mechanical and Nuclear Engineering / Kirby S. Chapman / Continued regulatory pressure necessitates the use of precisely designed turbochargers to create the design trapped equivalence ratio within large-bore stationary engines used in the natural gas transmission industry. The upgraded turbochargers scavenge the exhaust gases from the cylinder, and create the air manifold pressure and back pressure on the engine necessary to achieve a specific trapped mass. This combination serves to achieve the emissions reduction required by regulatory agencies. Many engine owner/operators request that an upgraded turbocharger be tested and verified prior to re-installation on engine. Verification of the mechanical integrity and airflow performance prior to engine installation is necessary to prevent field hardware iterations. Confirming the as-built turbocharger design specification prior to transporting to the field can decrease downtime and installation costs. There are however, technical challenges to overcome for comparing test-cell data to field conditions. This thesis discusses the required corrections and testing methodology to verify turbocharger onsite performance from data collected in a precisely designed testing apparatus. As the litmus test of the testing system, test performance data is corrected to site conditions per the design air specification. Prior to field installation, the turbocharger is fitted with instrumentation to collect field operating data to authenticate the turbocharger testing system and correction methods. The correction method utilized herein is the ASME Performance Test Code 10 (PTC10) for Compressors and Exhausters version 1997.

Proton exchange membrane (PEM) fuel cells, with low operating temperatures and high power density, are a reasonable candidate for use in mobile power generation. One large drawback to their use is that their fuel reformer requires not only fuel but also water, thereby requiring two separate reservoirs to be available. PEM fuel cells exhaust enough water in their oxidant stream to potentially meet the needs of the fuel reformer. If this water could be recovered and routed to the fuel reformer it would markedly increase the portability of PEM fuel cells. The goal of this research was to test a previously designed axial flow moisture separator. The separator was employed in a test bed which utilized compressed, heated air mixed with steam to simulate the oxidant exhaust conditions of a 25 kW PEM fuel cell. The simulated exhaust was saturated with water. The mixture was expanded through the turbine side of an automotive turbocharger, which dropped the temperature and pressure of the mixture, causing water to condense, making it available for separation. The humid air mixture was passed over an axial flow centrifugal separator and water was removed from the flow. The separator was tested in a variety of conditions with and without passing chilled water through the separator. The axial separator was tested independently, with a flow straightener preceding it, and with a commercially available centrifugal moisture separator in series following it. It was shown that cooling makes a significant impact on the separation rate while adding a flow straightener does not. Separation efficiencies of 19% on average were experienced without cooling, while efficiencies of 50% were experienced with 3.1 kW of cooling. The separation efficiency of the two moisture separators combined was found to be 31.7% which is 165% that of the axial separator alone under uncooled conditions.

L'impact de la dynamique des gaz sur la chaine d’air s'est imposé fortement en raison du contenu de la dynamique dans les nouveaux cycles de test automobile tels que le WLTC. Cela rend les modèles 0D actuels moins fiables car ils reposent sur plusieurs positions sur les cartographies mesurées sur des points de fonctionnements stationnaires. En outre, les phénomènes d'onde et les effets inertiels des gaz sont intrinsèquement négligés. Une méthodologie pour reproduire efficacement les effets d'ondes le long des conduites de moteurs à combustion interne a été présentée dans ce travail. L'idée est basée sur la combinaison des modèles à paramètres concentrés et les modèles quasi-unidimensionnels. Cette combinaison donne la possibilité de prendre les effets d'inertie de la dynamique des gaz tout en évitant le coût lourd de calcul de l'approche de modélisation 1D. La première partie s'est intéressée aux schémas numériques à une dimension, dans le but de les évaluer par rapport aux temps de calcul, d’exactitude et de définir une bonne référence pour davantage validations numériques pour les modèles réduits. Le modèle « quasi-Propagatory » était le meilleur candidat pour modéliser les ondes avec moins de puissance de calcul. Pour avoir une propre estimation de la pression de suralimentation, on s'est intéressé plus particulièrement au compresseur. Un modèle physique a été présenté on se basant sur les travaux de Martin et al. [55]. Finalement, les développements sont validés expérimentalement sur tous les points de fonctionnement du moteur. / Gas dynamics impact on air system dynamics and hence on combustion products, i.e. emissions, has imposed itself strongly due to the dynamics content in new test drive cycles such as the WLTC. This makes current real-time 0D models less reliable as they rely on stationary measured look up tables. In addition, wave phenomena and gas inertial effects are inherently neglected. This makes the estimation of the flow into and from the cylinder inaccurate. A methodology to efficiently reproduce wave effects along the internal combustion engine ducts was presented in this work. The idea relies on combining both lumped parameter and quasi-one-dimensional models. This combination gives the possibility to take inertial effects of gas dynamics while avoiding the heavy computational cost of the 1D modeling approach. The first part investigated one-dimensional numerical schemes, with the aim of evaluating them with respect to real-time applications and defining a good reference for further numerical validations for the low order models. The Quasi-Propagatory model was the best candidate to model waves with less computational power. To have a proper boost pressure estimation, more focus was on the compressor. A physics based model was presented based on [55]. Results have also shown a better interpretation and extrapolation ability. Finally, the developments have been validated experimentally using the complete engine operation map.

The work was concerned with the design, analysis and basic demonstration of a novel hydraulically assisted fixed geometry turbocharger system intended to help overcome some of the transient issues associated with current automotive boosting technologies. The novel system was based upon use of relatively lightweight parts, where kinetic energy is recovered during vehicle braking, stored in a simple hydraulic accumulator and then used later on to rapidly accelerate the engine's turbocharger. The turbocharger is fitted with a replacement centre housing enclosing a small impulse turbine, rigidly mounted to the turbocharger shaft and powered by a jet of oil. The aim is one of helping the engine to accelerate the vehicle while operating in a region of much higher brake efficiency due to the reduction in exhaust backpressure when compared with competing variable geometry and/or compound boosting technologies. The specific tasks involved concept design and computational analysis, including specification of the turbine type and geometry together with the associated hydraulic parts. A production turbocharger was reverse engineered to confirm the feasibility of packaging the hydraulic turbine system into the centre housing of a typical fixed geometry design. Finally an experimental rig was designed and manufactured to allow basic demonstration of the system, with speeds of up to ~90000 rpm @ 200 bar pressure from the pump via the accumulator achieved in ~0.8 seconds and clear potential for further optimisation. This hydraulic boosting system is capable of attaining 70% efficiency (a product of 0.85 from the oil pump, 0.95 from the hydraulic accumulator and 0.88 of Pelton wheel). The system has higher power density at low cost compared to the main competitor ‘E Boosting - with efficiency in the region of 90%’. The cost of E boosting and need for 48 volt battery makes it less favourable compared to the hydraulic turbine system. The concept has been shown to offer significant potential to assist a turbocharger to spool up via a Novel Hydraulic Kinetic Energy Recovery System approach.

Orientadores: Pedro Teixeira Lacava, Cristiane Aparecida Martins / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T17:20:07Z (GMT). No. of bitstreams: 1 Souza_AndersondeAlmeida_M.pdf: 2437052 bytes, checksum: 4d9d2474bf3d815f70a9be4908239d1a (MD5) Previous issue date: 2010 / Resumo: A cada introdução de uma nova norma de emissões de poluentes para motores diesel, modificações se fazem necessárias e um dos sistemas do motor que sofre diretamente tais modificações é o sistema de gerenciamento de ar, que é composto por: turbo-compressor,resfriador EGR e válvula EGR. Assim, todo um ciclo de desenvolvimento do motor é realizado com diversos tipos de ensaios, desde a definição dos componentes até a validação do motor. Com o intuito de reduzir a quantidade de ensaios realizados e o tempo durante a fase de definição dos componentes, uma alternativa é a utilização da simulação computacional. Com a ajuda de softwares específicos, é possível reduzir a quantidade de ensaios para a avaliação dos componentes, deixando para avaliação em dinamômetro apenas os ensaios das configurações que apresentaram os melhores resultados na simulação. Neste trabalho foi utilizado o software GTPOWER, sendo primeiramente realizada a calibração e a validação do modelo para um motor já existente, devido a gama de informações disponíveis sobre esse motor. Na seqüência, foi adicionado ao modelo outros componentes, como o sistema EGR, com o intuito de avaliar o comportamento de diferentes modelos de turbo-compressores em relação às suas características aerodinâmicas e também avaliar diferentes resfriadores EGR em relação à sua capacidade de troca térmica (efetividade) / Abstract: Every introduction of a new pollutant emissions standard for diesel engines, modifications are necessary and one of the engine systems that directly suffer such changes is the air management system, which is composed of turbocharger, EGR cooler and EGR valve. Thus an engine development cycle is carried out with several types of tests, from components definition to engine validation. Aiming at reducing the number of tests performed and the time during the definition phase of the components, an alternative is the use of computer simulation. With the help of specific software, it is possible to reduce the amount of tests for the assessment of the components, leaving only for assessment in the dynamometer testing the configurations that produced the best results in the simulation. In this work used the GT-POWER software. The model was first calibrated and validated for an existing engine, because of the range of information available for the engine. In the sequence, other components, such as the EGR system, were added to the model in order to evaluate the performance of different turbocharger models for aerodynamic characteristics and also evaluate different EGR coolers for thermal exchange capacity (effectiveness) / Mestrado / Motores / Mestre em Engenharia Automobilistica

Master of Science / Department of Mechanical and Nuclear Engineering / Kirby S. Chapman / This thesis outlines the development of a centrifugal compressor model for the Turbocharger Component Matching System (TuCMS) software package that can be used to inexpensively analyze turbocharger performance. The TuCMS can also be used to match turbocharger components to integrate and optimize turbocharger-engine performance. The software system is being developed with the intent to reduce the time taken to experimentally match a turbocharger with an engine, a task that is key to engine emission reductions. The TuCMS uses one-dimensional thermo-fluid equations to analyze the compressor side of a turbocharger. For each compressor component, the program calculates the velocities, pressures, temperatures, pressure losses, work consumption, and efficiencies for a specified set of turbocharger geometry, atmospheric conditions, rotational speed, and fluid mass flow rate. The compressor includes established loss models found in the open literature. The TuCMS utilizes a component-based architecture to simplify model enhancements. The TuCMS can be used as a cost effective engineering tool for preliminary turbocharger testing during engine upgrades and modifications. In this thesis, the TuCMS compressor model was used as an analysis tool to further understand the Variable Geometry Turbocharger (VGT) experimental results. The VGT is a unique turbocharger that can change the diffuser vane angle over a wide range of positions. The change in diffuser vane angle results in optimal turbocharger performance at various operating conditions, and potentially increases the operating range. The purpose for the use of the TuCMS compressor model analysis is to identify the change in performance as the diffuser vane angles are adjusted. The TuCMS can ideally be used as a control program for the VGT to adjust the diffuser vane angles as the compressor load changes and insure the compressor is operating at the highest efficiency.

The objective of this Master's thesis is to find, using genetic algorithm (GA), an optimal profile for lubricating gap of a thrust bearing of a turbocharger. Compared to the analytical profile, the optimal profile is expected to have minimized friction for an equivalent load capacity. Friction minimization is one way to increase the efficiency of the thrust bearing; it reduces the friction losses in the bearing. An initial problem was given: a thrust bearing with Load capacity 1000 N, inner and outer radii of 30mm and 60mm respectively, rotor speed of 45000 rpm and angle of running surface of $0.5^0$. Lubricant properties were also provided for the initial problem: oil density of $ 840 kg/m^3$, dynamic viscosity $(\eta)$ of 0.01 Pa.s With this data, the numerical solution of the Reynolds equation was computed using MATLAB. To obtain more information, the minimum lubricating gap thickness was also computed using MATLAB. With this information, the shape of the analytical profile, and its characteristics were found. The analytical profile was then used a guide to create a general profile. The general profile thus obtained is then optimized using GA. The characteristics of the generated profile is then computed and compared to that of the analytical profile.

Aim of this diploma thesis is the modification of naturally aspirated engine for Formula Student competition to turbocharged version. Modification which were made are based on the issue knowledge and calculations. The input data were obtained from 3D scanning and measurements, at the school laboratories. All 3D models were created in Pro / Engineer. Input data for the computional analysis was developed in Lotus Engine Simulation. Computational analysis was performed in ANSYS by finite element method. Calculations had to simulate a piston behavior at the critical situations where the engine is under the maxiumum load.

Aim of this diploma thesis is the turbocharger design calculation for single cylinder SI engine for Formula Student. This thesis includes a mathematical model of the engine, which is created in the Lotus Engine Simulation. This model applies for tuning the regulation of turbocharger charging pressure. Lotus uses the turbine waste gate valve for this regulation. The results of the simulation are the charging pressure,lengths of the intake manifold and etc. These parameters ensure the optimal engine qualities. The knowlege and results of the simulations are summarized at the conclusion.

This thesis deals with the adjustment racing turbocharged SI engine. The main objective was to design a suitable type of turbocharger and changes needed for proper engine operation. The upgrades were based on the stock Mitsubishi 4G63T engine.