Driven by the goal of decreasing emissions and pollutants towards a more sustainable future, the automotive industry is undergoing a rapid transition towards battery-powered electric vehicles. This shift to sustainable transport is fast-paced, and new technical solutions are being offered on a regular basis to fulfil the future needs for electric vehicles, including battery-electric trucks. This continuously necessitates a fast development of the battery-electric truck, along with the cooling system. To validate the cooling system, Scania's preferred approaches are testing and 3D simulations. However, these approaches are time-consuming and cannot match the pace of the design or the development. This thesis addresses the implementation of using 1D Simulations (GT-Suite) to carry out coolant filling simulations as a more efficient approach by studying the filling of the battery cooling system in an electric truck and, later, validating the results obtained with a test rig. In this thesis, different cases were defined, each adding more complexity to the circuit, and the parameters studied were the filling times and the location of air traps. Finally, a case with a closed circuit and running a coolant pump was developed to study the possibilities of devising quicker deaeration techniques for the circuit. The work completed in this thesis may be used as an example of how filling simulations can be performed with GT-Suite. This thesis is a good starting point, exploring a vast potential in using 1D Simulations to simulate the coolant-air interaction in a cooling system. Nonetheless, the findings revealed that GT-Suite v2020 and v2021 lack a robust model to properly simulate the interaction of coolant and air in certain sections of the circuit. In addition, the simulation model failed to obtain a steady-state solution in some cases resulting in discrepancies between the results from the test rig and the simulations. In conclusion, it was found that 1D simulations are not an ideal way forward when individual components of the cooling circuit are being considered, for example, the cooling plates, but are much quicker and seem to be a promising method to get an overview on a system level. / Fordonsindustrin drivs av målet att minska utsläppen och föroreningarna mot en mer hållbar framtid och genomgår en snabb omställning mot batteridrivna elfordon. Övergången till hållbara transporter går snabbt och nya tekniska lösningar erbjuds regelbundet för att möta de framtida behoven av elfordon, inklusive batteridrivna lastbilar. Detta kräver kontinuerligt en snabb utveckling av den batteri-elektriska lastbilen, tillsammans med kylsystemet. För att validera kylsystemet är Scanias föredragna metoder testning och 3D-simuleringar. Dessa tillvägagångssätt är dock tidskrävande och kan inte matcha takten i designen eller utvecklingen. Denna avhandling behandlar implementeringen av att använda 1D-simuleringar (GT-Suite) för att utföra kylvätskefyllningssimuleringar som ett effektivare tillvägagångssätt genom att studera fyllningen av batterikylsystemet i en elektrisk lastbil och senare validera resultaten som erhållits med en testrigg. I denna avhandling definierades olika fall, var och en lägga till mer komplexitet till kretsen, och de undersökta parametrarna var påfyllningstiderna och platsen för luftfällor. Slutligen utvecklades ett fall med en sluten krets och kör en kylvätskepump för att studera möjligheterna att utforma snabbare deaerationstekniker för kretsen. Arbetet i denna avhandling kan användas som ett exempel på hur fyllningssimuleringar kan utföras med GT-Suite. Denna avhandling är en bra utgångspunkt och utforskar en enorm potential i att använda 1D-simuleringar för att simulera kylvätske-luftinteraktionen i ett kylsystem. Resultaten visade dock att GT-Suite v2020 och v2021 saknar en robust modell för att korrekt simulera interaktionen mellan kylvätska och luft i vissa delar av kretsen. Dessutom kunde simuleringsmodellen inte få en steady state-lösning i vissa fall vilket resulterade i skillnader mellan resultaten från testriggen och simuleringarna. Sammanfattningsvis konstaterades det att 1D-simuleringar inte är en idealisk väg framåt när enskilda komponenter i kylkretsen övervägs, till exempel kylplattorna, men är mycket snabbare och verkar vara en lovande metod för att få en översikt på systemnivå.

<p>The aim is to share experience gained when simulating (and doing measurements on) the turbocharged SI-engine as well as describing the limits of current state of the technology. In addition an overview of current boosting systems is provided.</p><p>The target readers of this text are engineers employed in the engine industry as well as academia who will get in contact, or is experienced, with 1D engine performance simulation and/or boosting systems. Therefore the text requires general knowledge about engines.</p><p>The papers included in the thesis are, in reverse chronological order:</p><p>[8] SAE 2005-XX-XXX Calculation accuracy of pulsating flow through the turbine of SI-engine turbochargers - Part 2 Measurements, simulation correlations and conclusions Westin & Ångström</p><p>To be submitted to the 2005 SAE Powertrain and Fluid Systems Conference in San Antonio</p><p>[7] SAE 2005-01-2113 Optimization of Turbocharged Engines’ Transient Response with Application on a Formula SAE / Student engine Westin & Ångström</p><p>Approved for publication at the 2005 SAE Spring Fuels and Lubricants Meeting in Rio de Janeiro</p><p>[6] SAE 2005-01-0222 Calculation accuracy of pulsating flow through the turbine of SI-engine turbochargers - Part 1 Calculations for choice of turbines with different flow characteristics Westin & Ångström</p><p>Published at the 2005 SAE World Congress in Detroit April 11-14, 2005</p><p>[5] SAE 2004-01-0996 Heat Losses from the Turbine of a Turbocharged SI-Engine – Measurements and Simulation Westin, Rosenqvist & Ångström</p><p>Presented at the 2004 SAE World Congress in Detroit March 8-11, 2004</p><p>[4] SAE 2003-01-3124 Simulation of a turbocharged SI-engine with two software and comparison with measured data Westin & Ångström</p><p>Presented at the 2003 SAE Powertrain and Fluid Systems Conference in Pittsburgh</p><p>[3] SIA C06 Correlation between engine simulations and measured data - experiences gained with 1D-simulations of turbocharged SI-engines Westin, Elmqvist & Ångström</p><p>Presented at the SIA International Congress SIMULATION, as essential tool for risk management in industrial product development in Poissy, Paris September 17-18 2003</p><p>[2] IMechE C602/029/2002 A method of investigating the on-engine turbine efficiency combining experiments and modelling Westin & Ångström</p><p>Presented at the 7th International Conference on Turbochargers and Turbocharging in London 14-15 May, 2002</p><p>[1] SAE 2000-01-2840 The Influence of Residual Gases on Knock in Turbocharged SI-Engines Westin, Grandin & Ångström</p><p>Presented at the SAE International Fall Fuels and Lubricants Meeting in Baltimore October 16-19, 2000</p><p>The first step in the investigation about the simulation accuracy was to model the engine as accurately as possible and to correlate it against as accurate measurements as possible. That work is covered in the chapters 3 and 5 and in paper no. 3 in the list above. The scientific contribution here is to isolate the main inaccuracy to the simulation of turbine efficiency.</p><p>In order to have anything to compare the simulated turbine efficiency against, a method was developed that enables calculation of the CA-resolved on-engine turbine efficiency from measured data, with a little support from a few simulated properties. That work was published in papers 2 and 8 and is the main scope of chapter 6 in the thesis. The scientific contributions here are several:</p><p>· The application on a running SI-engine is a first</p><p>· It was proven that CA-resolution is absolutely necessary in order to have a physically and mathematically valid expression for the turbine efficiency. A new definition of the time-varying efficiency is developed.</p><p>· It tests an approach to cover possible mass accumulation in the turbine housing</p><p>· It reveals that the common method for incorporating bearing losses, a constant mechanical efficiency, is too crude.</p><p>The next step was to investigate if different commercial codes differ in the results, even though they use equal theoretical foundation. That work is presented in chapter 4, which corresponds to paper 4. This work has given useful input to the industry in the process of choosing simulation tools.</p><p>The next theory to test was if heat losses were a major reason for the simulation accuracy. The scientific contribution in this part of the work was a model for the heat transport within the turbocharger that was developed, calibrated and incorporated in the simulations. It was concluded that heat losses only contributed to a minor part of the inaccuracy, but that is was a major reason for a common simulation error of the turbine outlet temperature, which is very important when trying to simulate catalyst light off. This work was published in paper 5 and is covered in chapter 7.</p><p>Chapter 8, and papers 6 and 8, covers the last investigation of this work. It is a broad study where the impact of design changes of both manifold at turbines on both simulation accuracy as well as engine performance. The scientific contribution here is that the common theory that the simulation inaccuracy is proportional to the pulsation amplitude of the flow is non-valid. It was shown that the reaction was of minor importance for the efficiency of the turbine in the pulsating engine environment. Furthermore it presents a method to calculate internal flow properties in the turbine, by use of a steady-flow design software in a quasi-steady procedure. Of more direct use for the industry is important information of how to design the manifolds as well as it sheds more light on how the turbine works under unsteady flow, for instance that the throat area is the single most important property of the turbine and that the system has a far larger sensitivity to this parameter than to any other design parameters of the turbine. Furthermore it was proven that the variation among individual turbines is of minor importance, and that the simulation error was of similar magnitude for different turbine manufacturers.</p><p>Paper 7, and chapter 9, cover a simulation exercise where the transient performance of turbocharged engines is optimised with help from factorials. It sorts out the relative importance of several design parameters of turbocharged engines and gives the industry important information of where to put the majority of the work in order to maximize the efficiency in the optimisation process.</p><p>Overall, the work presented in this thesis has established a method for calibration of models to measured data in a sequence that makes the process efficient and accurate. It has been shown that use of controllers in this process can save time and effort tenfold or more.</p><p>When designing turbocharged engines the residual gas is a very important factor. It affects both knock sensitivity and the volumetric efficiency. The flow in the cylinder is in its nature of more dimensions than one and is therefore not physically modelled in 1D codes. It is modelled through models of perfect mixing or perfect displacement, or at a certain mix between them. Before the actual project started, the amount of residual gases in an engine was measured and it’s influence on knock was established and quantified. This was the scope of paper 1. This information has been useful when interpreting the model results throughout the entire work.</p>

The study of crowding effects on particle diffusion is a large subject with implications in many scientific areas. The studies span from pure theoretical calculations to experiments actually measuring the movement of proteins diffusing in a cell. Even though the subject is important and has been studied heavily there are still aspects not fully understood.   This report describes a Monte Carlo simulation approach (Gillespie algorithm) to study the effects of crowding on particle diffusion in a quasi one-dimensional system. With quasi meaning that the particles diffuses on a one-dimensional lattice but has the possibility to disassociate from the lattice and then rebind at a latter stage. Different binding strategies are considered: rebinding to the same location and randomly choosing the binding location. The focus of the study is how these strategies affects the mobility (diffusion coefficient) of a tracer particle. The main result of this thesis is a graph showing the diffusion coefficient as a function of the binding rate for different binding strategies and particle densities. We provide analytical estimates for the diffusion coefficient in the unbinding rate limits which show good agreement with the simulations. / Hur "trängsel" (från engelskans "crowding" t ex molecular crowding) påverkar diffusionsprocesser är viktigt inom många olika vetenskapliga områden. Forskningen som för tillfället utförs sträcker sig från rent teoretiska beräkningar till experiments där man kan följa enskilda proteiners rörelse i en cell. Även fast ämnet är viktig och väl undersökt finns det fortfarande många aspekter som man inte förstår till fullo. I det här examensarbetet beskrivs en Monte Carlo metod (Gillespie algoritmen) för att studera hur trängsel påverkar en partikel som diffunderar i ett "nästan" en-dimensonellt system. Det är nästan en-dimensionellt i det avsedde att partiklarna diffunderar på ett gitter men kan binda av från gittret och binda tillbaka i ett senare skedde. Olika metoder för hur partiklarna binder till gittret undersöks: Återbinding till avbindingsplatsen och slumpmässigt vald återbindingsplats. Fokus ligger på att förklara hur dessa påverkar mobiliteten (diffusionskonstanten) av en spårningspartikel (tracer particle). Resultatet är en graf som visar diffusionskonstanten för spårningspartikeln som en funktion av avbindingsfrekvens för olika bindingstrategier och partikeldensiteter. Vi ger också analytiska resultat i gränsvärdet för höga och låga avbindingstakter vilka stämmer bra överens med simuleringar.

The thermal regime of a gearbox is of considerable importance to its performance. Several significant gearbox parameters, such as the efficiency and fatigue life of its components, are temperature dependent. It is thus important to be able to determine the temperatures of the gearbox components during operation, but they are difficult to measure experimentally. A simulation model capable of predicting these temperatures would therefore be a valuable tool. The objective of this master’s thesis was to create a model capable of simulating the thermal regime of a truck gearbox during operation. To do this, mechanical losses in the gearbox, heat exchange with the surroundings, as well as heat transfer between components had to be accounted for. The model was created using the 1D simulation software LMS Imagine.Lab Amesim 14.0, and is based on a combination of mechanical and thermal networks. Details of the mechanical and thermal interactions between components are calculated using empirical and analytical formulas for mechanical losses and heat transfer. The result of the thesis is a model which can be used to simulate either real or idealised load cases, from which temperatures of gear wheels, shafts, bearings, housing and gearbox oil may be studied, as well as gearbox losses and heat transfer. Comparisons between simulated and measured gearbox efficiencies show good correlation. It is also shown that the model can predict oil temperatures which agree with in-vehicle measurements. Due to a lack of measurement data, most simulated component temperatures cannot be compared to measured values. However, temperature measurements performed for one of the gear wheels indicate that the model can be used to predict their temperature. In order to demonstrate the capabilities of the model, example results from both real and idealised load cases are presented.

Dicelis, G. E., Estudo Integrado da Camada de Basalto em Bebedouro SP, Bacia do Paraná: Relocalização dos sismos induzidos por poços tubulares, 2011. Dissertação de Mestrado Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, SP. A partir de 2004, a população do distrito de Andes, Bebedouro (SP), passou a sentir pequenos tremores de terra. Uma rede sismográfica instalada em 2005 mostrou que os sismos locais são induzidos por poços tubulares profundos usados para irrigação de lavouras (Assumpção et al., 2007). Neste projeto de pesquisa foi melhorada a localização desses sismos, usando análise da forma de onda e os tempos de chegada das ondas P e S, com o propósito de efetuar uma melhor análise da sismicidade induzida. Para isto foram aproveitados resultados de estudos anteriores como sísmica de refração, dispersão de ondas de superfície, sondagem elétrica vertical, função do receptor e TDEM. Para obter o melhor modelo de velocidades 1D, foram testados diferentes algoritmos de localização e técnicas de relocalização de hipocentros, para aproximadamente 3000 microtremores gravados pela rede sismográfica no período 2005 2010. Os resultados mostraram que as profundidades focais dos sismos relocalizados ficaram em sua maioria dentro da camada de basalto, a menos de 500m de profundidade. Este resultado confirma que os sismos estão relacionados com a perturbação do equilíbrio de tensões (pressões) geológicas, em zonas de fraturas já existentes dentro da camada de basalto. Foi usada uma combinação de correlação cruzada e tempos de chegada para analisar um conjunto de sismos, baseada na similaridade dos seus sismogramas. Foi melhorada a distribuição hipocentral o que permitiu determinar claramente uma solução do plano focal de um cluster, o que indicou a existência de uma falha normal de orientação WNW-ESSE e mergulho para o norte, com extensão NNE-SSW (eixo-T). Este mecanismo pode complementar os dados de esforços na região sudeste. / Dicelis, G. E., Integrated Study of the basalt layer in Bebedouro SP, Paraná Basin: Relocation of earthquakes induced by wells, 2011. Master dissertation - Institute of Astronomy, Geophysics and Atmospheric Sciences of the University of Sao Paulo, Brazil. Since 2004 the population of the district of Andes, Bebedouro SP, began to feel small earthquakes. A seismograph network installed in 2005 showed that earthquakes are caused by local deep wells used for irrigation of crops (Assumpção et al., 2007). In this research project we improved the location of these earthquakes, using analysis of waveform and the arrival times of P and S waves, in order to make a better analysis of the induced seismicity. To better relocate the events we determined a velocit model using results of previous studies such as seismic refraction, surface wave dispersion, vertical electrical sounding, receiver function and TDEM. The best fit 1D model was achieved testing different localization algorithms and techniques for relocation of hypocenters for approximately 3000 microtremors recorded by seismograph network to the period 2005 2010. The results showed that the focal depths of the relocated earthquakes are mostly within the basalt layer, less than 500m depth. This confirms that the earthquakes are related with disturbance of geological stresses (pressures) in pre-existing fracture zones within the basalt layer. We used a combination of cross-correlation and arrival times for analyze a set of earthquakes, based on the similarity of their recorded seismograms. The hypocentral distribution was improved allowing a clear determination of the best fit fault plane solution for one cluster, which indicates the existence of a normal fault with direction WNW-ESE and dip to the north, with NNE-SSW extension (T-axis). This mechanism may complement the stress data in the Southeast Brazil.

This thesis describes electrical measurements performed on low dimensional p-type devices, fabricated from GaAs/AlGaAs heterostructures. The Coulomb interaction between holes is similar to that between electrons. However, the kinetic energy is suppressed, which makes interaction effects particularly important. Holes may also be used to study band structure effects which arise from spin-orbit coupling in the valence band. The effects of Coulomb interactions in low dimensional electron systems are currently being studied extensively. Experiments presented in this thesis indicate the possible importance of Coulomb exchange interactions in both one and two dimensional hole systems (1DHSs,2DHSs). Tilted magnetic field studies of 2DHSs in the quantum Hall regime indicate that Landau levels at even filling factors will not cross. For high filling factor, this is attributed to a spin-orbit mixing effect which arises from the low symmetry ofthe system. At lower filling factor, activation-energy measurements verify that the energy gaps decrease and then increase as the field is tilted. However, the energy gap versus field dependences do not exhibit the curvature that might be expected from a perturbative anticrossing. It is speculated that the origin of this effect is a phase transition driven by the exchange interaction. Balanced arguments contrasting the relative strengths of the mixing and interactions theories are provided. The second part of this thesis describes a new method for the fabrication ofballistic 1DHSs, which exhibit clear conductance quantization. The quantization changes from even to odd multiples of e2/h as a function of the magnetic field in the plane of the heterostructure, as 'spin splitting' causes the 1D subbands to cross. Measurements of the 1D subband energy spacings are used together with the magnetic fields at which the crossings occur to calculate the in-plane g factors of the 1D subbands. These are found to increase as the number of occupied 1D subbands decreases. This enhancement of the g factor is attributed to exchange interactions; possible mixing explanations are also discussed. At higher magnetic fields, the pattern of quantization features shows that the subbands have crossed many times, and that the 1DHS can be strongly magnetized.

Plasma, the fourth state of matter, is a gas in which a significant portion of the atoms are ionized. It is estimated that more than 99% of the material in the visible universe is in the plasma state. The process that stars, including our sun, combine atomic nuclei and produce large amounts of energy is called thermonuclear fusion. It is anticipated future energy demands will be met by large terrestrial devices harnessing the energy of nuclear fusion. A gas hot enough to produce the number of atomic collisions needed for fusion is necessarily in the plasma state. Therefore, plasmas are of great interest to researchers studying nuclear fusion. Stars are massive enough that the gravitational attraction heats and confines the plasma. Gravitational confinement cannot be used to confine fusion plasmas on Earth. Material containers cause cooling, which prevent a plasma from maintaining the high temperature needed for fusion. Fortunately plasmas have electrical properties, which allow them to be controlled by strong magnetic fields. Although serious research into controlled thermonuclear fusion began over 60 years ago, only a couple of man-made devices are even close to obtaining more energy from fusion than is put into them. One difficulty lies in understanding the physics of particle collisions. A relative few particle collisions result in the fusion of atomic nuclei, while the vast majority of collisions are understood in terms of the electrostatic force between particles. My work has been to create an a computer code, which can be executed in parallel on supercomputers, to quickly and accurately calculate the evolution of a plasma due to particle collisions. This work explains the physics and mathematics underlying our code, as well as several tests which demonstrate the code is working as expected.

Ce travail a pour objectif de proposer des méthodes pour améliorer la compréhension des processus d'évolution de la Loire moyenne sur quelques décennies. L'analyse des évolutions morphologiques est réalisée en découpant le secteur d'étude en tronçons géomorphologiquement homogènes. Une diminution de la pente et une réduction de la largeur de la bande active entre 1955 et 1996 sont observées. Suite à l'arrêt des extractions (1996), les ajustements se poursuivent de façon plus modérés. Des simplifications géométriques et hydrologiques sont ensuite introduites dans un modèle de trans- port solide unidimensionnel (RubarBE) afin d'être comparées aux résultats obtenus avec la géométrie détaillée et la chronique de débit complète. La géométrie simplifiée permet une modélisation des évo- lutions du lit pertinente tout en réduisant le temps de calcul ; la simplification des chroniques de débit illustre la sensibilité des modèles numériques hydro-sédimentaires à l'hydrologie. Enfin, l'ap- plication des simplifications sur l'ensemble de la Loire moyenne sur la période 1996-2006 confirme les tendances observées par l'analyse des données.

The aim is to share experience gained when simulating (and doing measurements on) the turbocharged SI-engine as well as describing the limits of current state of the technology. In addition an overview of current boosting systems is provided. The target readers of this text are engineers employed in the engine industry as well as academia who will get in contact, or is experienced, with 1D engine performance simulation and/or boosting systems. Therefore the text requires general knowledge about engines. The papers included in the thesis are, in reverse chronological order: [8] SAE 2005-XX-XXX Calculation accuracy of pulsating flow through the turbine of SI-engine turbochargers - Part 2 Measurements, simulation correlations and conclusions Westin &amp; Ångström To be submitted to the 2005 SAE Powertrain and Fluid Systems Conference in San Antonio [7] SAE 2005-01-2113 Optimization of Turbocharged Engines’ Transient Response with Application on a Formula SAE / Student engine Westin &amp; Ångström Approved for publication at the 2005 SAE Spring Fuels and Lubricants Meeting in Rio de Janeiro [6] SAE 2005-01-0222 Calculation accuracy of pulsating flow through the turbine of SI-engine turbochargers - Part 1 Calculations for choice of turbines with different flow characteristics Westin &amp; Ångström Published at the 2005 SAE World Congress in Detroit April 11-14, 2005 [5] SAE 2004-01-0996 Heat Losses from the Turbine of a Turbocharged SI-Engine – Measurements and Simulation Westin, Rosenqvist &amp; Ångström Presented at the 2004 SAE World Congress in Detroit March 8-11, 2004 [4] SAE 2003-01-3124 Simulation of a turbocharged SI-engine with two software and comparison with measured data Westin &amp; Ångström Presented at the 2003 SAE Powertrain and Fluid Systems Conference in Pittsburgh [3] SIA C06 Correlation between engine simulations and measured data - experiences gained with 1D-simulations of turbocharged SI-engines Westin, Elmqvist &amp; Ångström Presented at the SIA International Congress SIMULATION, as essential tool for risk management in industrial product development in Poissy, Paris September 17-18 2003 [2] IMechE C602/029/2002 A method of investigating the on-engine turbine efficiency combining experiments and modelling Westin &amp; Ångström Presented at the 7th International Conference on Turbochargers and Turbocharging in London 14-15 May, 2002 [1] SAE 2000-01-2840 The Influence of Residual Gases on Knock in Turbocharged SI-Engines Westin, Grandin &amp; Ångström Presented at the SAE International Fall Fuels and Lubricants Meeting in Baltimore October 16-19, 2000 The first step in the investigation about the simulation accuracy was to model the engine as accurately as possible and to correlate it against as accurate measurements as possible. That work is covered in the chapters 3 and 5 and in paper no. 3 in the list above. The scientific contribution here is to isolate the main inaccuracy to the simulation of turbine efficiency. In order to have anything to compare the simulated turbine efficiency against, a method was developed that enables calculation of the CA-resolved on-engine turbine efficiency from measured data, with a little support from a few simulated properties. That work was published in papers 2 and 8 and is the main scope of chapter 6 in the thesis. The scientific contributions here are several: · The application on a running SI-engine is a first · It was proven that CA-resolution is absolutely necessary in order to have a physically and mathematically valid expression for the turbine efficiency. A new definition of the time-varying efficiency is developed. · It tests an approach to cover possible mass accumulation in the turbine housing · It reveals that the common method for incorporating bearing losses, a constant mechanical efficiency, is too crude. The next step was to investigate if different commercial codes differ in the results, even though they use equal theoretical foundation. That work is presented in chapter 4, which corresponds to paper 4. This work has given useful input to the industry in the process of choosing simulation tools. The next theory to test was if heat losses were a major reason for the simulation accuracy. The scientific contribution in this part of the work was a model for the heat transport within the turbocharger that was developed, calibrated and incorporated in the simulations. It was concluded that heat losses only contributed to a minor part of the inaccuracy, but that is was a major reason for a common simulation error of the turbine outlet temperature, which is very important when trying to simulate catalyst light off. This work was published in paper 5 and is covered in chapter 7. Chapter 8, and papers 6 and 8, covers the last investigation of this work. It is a broad study where the impact of design changes of both manifold at turbines on both simulation accuracy as well as engine performance. The scientific contribution here is that the common theory that the simulation inaccuracy is proportional to the pulsation amplitude of the flow is non-valid. It was shown that the reaction was of minor importance for the efficiency of the turbine in the pulsating engine environment. Furthermore it presents a method to calculate internal flow properties in the turbine, by use of a steady-flow design software in a quasi-steady procedure. Of more direct use for the industry is important information of how to design the manifolds as well as it sheds more light on how the turbine works under unsteady flow, for instance that the throat area is the single most important property of the turbine and that the system has a far larger sensitivity to this parameter than to any other design parameters of the turbine. Furthermore it was proven that the variation among individual turbines is of minor importance, and that the simulation error was of similar magnitude for different turbine manufacturers. Paper 7, and chapter 9, cover a simulation exercise where the transient performance of turbocharged engines is optimised with help from factorials. It sorts out the relative importance of several design parameters of turbocharged engines and gives the industry important information of where to put the majority of the work in order to maximize the efficiency in the optimisation process. Overall, the work presented in this thesis has established a method for calibration of models to measured data in a sequence that makes the process efficient and accurate. It has been shown that use of controllers in this process can save time and effort tenfold or more. When designing turbocharged engines the residual gas is a very important factor. It affects both knock sensitivity and the volumetric efficiency. The flow in the cylinder is in its nature of more dimensions than one and is therefore not physically modelled in 1D codes. It is modelled through models of perfect mixing or perfect displacement, or at a certain mix between them. Before the actual project started, the amount of residual gases in an engine was measured and it’s influence on knock was established and quantified. This was the scope of paper 1. This information has been useful when interpreting the model results throughout the entire work.

Performance-based measures are used to validate and quantify how likely the system’s results resemble that of the actual data. Its application in inundation studies is performed by comparing the extents of the predicted flood to the real event by measuring their overlap size and getting the percentage of this size to the union of both data. In this study, performances of 1- and 2-dimensional flow models were assessed when used with different topographic data sources, rasterisation cell sizes, mesh resolution and Manning’s values with the help of Geographic Information Systems (GIS). The Generalised Likelihood Uncertainty Estimation (GLUE) was also implemented to evaluate the behaviour and the uncertainties of the Hydrologic Engineering Center-River Analysis System (HEC-RAS) steady-flow model in delineating the inundation extents when various sets of friction coefficients for floodplain and channel were utilised as inputs. Although it was not possible to perform the GLUE procedure with Telemac-2D due to the simulation time, Manning’s n performances’ effects were evaluated using ten randomly selected sets of friction for the channel and floodplain. The LiDAR data, which had the highest resolution, performed well in all simulations, followed by Lantmäteriet data at 50 m resolution. The lowest resolution Digital Terrain Elevation Data (DTED) showed poor resemblance to the actual event and big misrepresentations of flooded areas. Rasterisation cell sizes in HEC-RAS showed minimal effect to the inundation limits when used between 1 m and 5 m, but performance started to deteriorate at 10 m (Lantmäteriet) and 20 m (LiDAR). The 10 m mesh resolution used for LiDAR behaved poorer than the 20 m mesh, which performed well in the different 2D simulations. For HEC-RAS, =0.033 to 0.05 performed well when paired with =0.02 to 0.10. It was apparent, therefore, that the channel’s Manning’s n affected the performances of the floodplain’s . Furthermore, the study also showed that using heterogeneous roughness values corresponding to the different land use classes is not as effective as using single channel and floodplain’s Manning. The dependence of the floodplain’s roughness to the channel’s friction values had also been manifested by Telemac, even though it required lower values than the 1D simulator. = 0.007 to 0.019   and =0.01 to 0.04 gave good performance to the 2D system. In terms of the overall model performance, HEC-RAS 1D exhibited good results for Testeboån. Even when the average distances to the actual data were estimated, the breadths were shorter compared to the most optimal output of the two-dimensional simulator, which showed more overestimated areas, despite the fact that the overlap size with the 1977 actual event was better than HEC-RAS. It could be because the measures-of-fit took into consideration the areal sizes that were over- and under-predicted aside from the overlap sizes between the observed and modelled results. This could be the same reason with the mean distances produced, wherein higher values were computed for Telemac-2D due to its bigger gap from the actual flood as brought by the enlargement in the flood extents. But it was also made known in the study that such ambiguities in the model performance were further contributed by the characteristics of the floodplain’s topography of being flat. Testeboån’s inclination to the banks was averaged at 0.027 m/m, with the central portion at 0.002 m/m. The middle portion of the floodplain was illustrated to contain more uncertain regions, where water extents changed easily as the parameters were altered. Distances greater than 200 m were also mostly located within these inclination values or within 0.005 to 0.006 m/m. The response of distance to the floodplain’s gradient improved when the slope value became higher, and this had been particularly noticed between 0 to 50 m.