USER'S GUIDE FOR ADVANCED PROCESS SIMULATION SOFTWARE APROS 5

Tässä diplomityössä tehtiin käyttäjän opas kehittyneelle prosessisimulointiohjelmistolle APROS 5. Opas on osa VTT Energialle tehtävää APROS 5 käyttäjän koulutuspakettia, joka julkaistaan myöhemmin CD-ROM -muotoisena. Prosessisimulointiohjelmistoa AAPROS 5 voidaan käyttää termohydraulisten prosessien, automaatiopiirien ja sähköjärjestelmien mallinnuksessa. Ohjelma sisältää myös neutroniikkamallin ydinreaktorin käyttäytymisen mallintamiseksi. APROS:in aikaisemmilla UNIX-ympäristössä toimivilla versioilla on toteutettu useita ydinvoimalaitosten turvallisuustutkimukseen liittyviä analyysejä ja sekä ydinvoimalaitosten että konventionaalisten voimalaitosten koulutussimulaattoreita. APROS 5 toimii Windows NT -ympäristössä ja on oleellisesti erilainen käyttää kuin aikaisemmat versiot. Tämän myötä syntyi tarve uudelle käyttäjän oppaalle. Käyttäjän oppaassa esitetään APROS 5:n tärkeimmät toiminnot, mallinnuksen periaatteet ja termohydraulisten ja neutroniikan ratkaisumallit. Lisäksi oppaassa esitetään esimerkki, jossa mallinnetaan yksinkertaistettu VVER-440 -tyyppisen ydinvoimalaitoksen primääripiiri. Yksityiskohtaisempaa tietoa ohjelmistosta on saatavilla APROS 5 -dokumentaatiosta.

Understanding Optical Trapping Phenomena: a Simulation for Undergraduates

Optical trapping is an attractive and multidisciplinary topic that has become the center of attention to a large number of researchers. Moreover, it is a suitable subject for advanced students that requires a knowledge of a wide range of topics. As a result, it has been incorporated into some syllabuses of both undergraduate and graduate programs. In this paper, basic concepts in laser trapping theory are reviewed. To provide a better understanding of the underlying concepts for students, a Java application for simulating the behavior of a dielectric particle trapped in a highly focused beam has been developed. The program illustrates a wide range of theoretical results and features, such as the calculation of the force exerted by a beam in the Mie and Rayleigh regimes or the calibration of the trap stiffness. Some examples that are ready to be used in the classroom or in the computer lab are also supplied.

3D Stripixel Detectors Simulation

Solid-state silicon detectors have replaced conventional ones in almost all recent high-energy physics experiments. Pixel silicon sensors don't have any alternative in the area near the interaction point because of their high resolution and fast operation speed. However, present detectors hardly withstand high radiation doses. Forthcoming upgrade of the LHC in 2014 requires development of a new generation of pixel detectors which will be able to operate under ten times increased luminosity. A planar fabrication technique has some physical limitations; an improvement of the radiation hardness will reduce sensitivity of a detector. In that case a 3D pixel detector seems to be the most promising device which can overcome these difficulties. The objective of this work was to model a structure of the 3D stripixel detector and to simulate electrical characteristics of the device. Silvaco Atlas software has been used for these purposes. The structures of single and double sided dual column detectors with active edges were described using special command language. Simulations of these detectors have shown that electric field inside an active area has more uniform distribution in comparison to the planar structure. A smaller interelectrode space leads to a stronger field and also decreases the collection time. This makes the new type of detectors more radiation resistant. Other discovered advantages are the lower full depletion voltage and increased charge collection efficiency. So the 3D stripixel detectors have demonstrated improved characteristics and will be a suitable replacement for the planar ones.

Performance of small wind turbines: simulation of electricity supply to loads connected to the public or isolated grid

ABSTRACT The successful in the implementation of wind turbines depends on several factors, including: the wind resource at the installation site, the equipment used, project acquisition and operational costs. In this paper, the production of electricity from two small wind turbines was compared through simulation using the computer software HOMER - a national model of 6kW and an imported one of 5kW. The wind resources in three different cities were considered: Campinas (SP/BR), Cubatão (São Paulo/BR) and Roscoe (Texas/ USA). A wind power system connected to the grid and a wind isolated system - batteries were evaluated. The results showed that the energy cost ($/kWh) is strongly dependent on the windmill characteristics and local wind resource. Regarding the isolated wind system – batteries, the full supply guarantee to the simulated electrical load is only achieved with a battery bank with many units and high number of wind turbines, due to the intermittency of wind power.

Thinking Outside the Box: Enhancing Science Teaching by Combining (Instead of Contrasting) Laboratory and Simulation Activities

The focus of the present work was on 10- to 12-year-old elementary school students’ conceptual learning outcomes in science in two specific inquiry-learning environments, laboratory and simulation. The main aim was to examine if it would be more beneficial to combine than contrast simulation and laboratory activities in science teaching. It was argued that the status quo where laboratories and simulations are seen as alternative or competing methods in science teaching is hardly an optimal solution to promote students’ learning and understanding in various science domains. It was hypothesized that it would make more sense and be more productive to combine laboratories and simulations. Several explanations and examples were provided to back up the hypothesis. In order to test whether learning with the combination of laboratory and simulation activities can result in better conceptual understanding in science than learning with laboratory or simulation activities alone, two experiments were conducted in the domain of electricity. In these experiments students constructed and studied electrical circuits in three different learning environments: laboratory (real circuits), simulation (virtual circuits), and simulation-laboratory combination (real and virtual circuits were used simultaneously). In order to measure and compare how these environments affected students’ conceptual understanding of circuits, a subject knowledge assessment questionnaire was administered before and after the experimentation. The results of the experiments were presented in four empirical studies. Three of the studies focused on learning outcomes between the conditions and one on learning processes. Study I analyzed learning outcomes from experiment I. The aim of the study was to investigate if it would be more beneficial to combine simulation and laboratory activities than to use them separately in teaching the concepts of simple electricity. Matched-trios were created based on the pre-test results of 66 elementary school students and divided randomly into a laboratory (real circuits), simulation (virtual circuits) and simulation-laboratory combination (real and virtual circuits simultaneously) conditions. In each condition students had 90 minutes to construct and study various circuits. The results showed that studying electrical circuits in the simulation–laboratory combination environment improved students’ conceptual understanding more than studying circuits in simulation and laboratory environments alone. Although there were no statistical differences between simulation and laboratory environments, the learning effect was more pronounced in the simulation condition where the students made clear progress during the intervention, whereas in the laboratory condition students’ conceptual understanding remained at an elementary level after the intervention. Study II analyzed learning outcomes from experiment II. The aim of the study was to investigate if and how learning outcomes in simulation and simulation-laboratory combination environments are mediated by implicit (only procedural guidance) and explicit (more structure and guidance for the discovery process) instruction in the context of simple DC circuits. Matched-quartets were created based on the pre-test results of 50 elementary school students and divided randomly into a simulation implicit (SI), simulation explicit (SE), combination implicit (CI) and combination explicit (CE) conditions. The results showed that when the students were working with the simulation alone, they were able to gain significantly greater amount of subject knowledge when they received metacognitive support (explicit instruction; SE) for the discovery process than when they received only procedural guidance (implicit instruction: SI). However, this additional scaffolding was not enough to reach the level of the students in the combination environment (CI and CE). A surprising finding in Study II was that instructional support had a different effect in the combination environment than in the simulation environment. In the combination environment explicit instruction (CE) did not seem to elicit much additional gain for students’ understanding of electric circuits compared to implicit instruction (CI). Instead, explicit instruction slowed down the inquiry process substantially in the combination environment. Study III analyzed from video data learning processes of those 50 students that participated in experiment II (cf. Study II above). The focus was on three specific learning processes: cognitive conflicts, self-explanations, and analogical encodings. The aim of the study was to find out possible explanations for the success of the combination condition in Experiments I and II. The video data provided clear evidence about the benefits of studying with the real and virtual circuits simultaneously (the combination conditions). Mostly the representations complemented each other, that is, one representation helped students to interpret and understand the outcomes they received from the other representation. However, there were also instances in which analogical encoding took place, that is, situations in which the slightly discrepant results between the representations ‘forced’ students to focus on those features that could be generalised across the two representations. No statistical differences were found in the amount of experienced cognitive conflicts and self-explanations between simulation and combination conditions, though in self-explanations there was a nascent trend in favour of the combination. There was also a clear tendency suggesting that explicit guidance increased the amount of self-explanations. Overall, the amount of cognitive conflicts and self-explanations was very low. The aim of the Study IV was twofold: the main aim was to provide an aggregated overview of the learning outcomes of experiments I and II; the secondary aim was to explore the relationship between the learning environments and students’ prior domain knowledge (low and high) in the experiments. Aggregated results of experiments I & II showed that on average, 91% of the students in the combination environment scored above the average of the laboratory environment, and 76% of them scored also above the average of the simulation environment. Seventy percent of the students in the simulation environment scored above the average of the laboratory environment. The results further showed that overall students seemed to benefit from combining simulations and laboratories regardless of their level of prior knowledge, that is, students with either low or high prior knowledge who studied circuits in the combination environment outperformed their counterparts who studied in the laboratory or simulation environment alone. The effect seemed to be slightly bigger among the students with low prior knowledge. However, more detailed inspection of the results showed that there were considerable differences between the experiments regarding how students with low and high prior knowledge benefitted from the combination: in Experiment I, especially students with low prior knowledge benefitted from the combination as compared to those students that used only the simulation, whereas in Experiment II, only students with high prior knowledge seemed to benefit from the combination relative to the simulation group. Regarding the differences between simulation and laboratory groups, the benefits of using a simulation seemed to be slightly higher among students with high prior knowledge. The results of the four empirical studies support the hypothesis concerning the benefits of using simulation along with laboratory activities to promote students’ conceptual understanding of electricity. It can be concluded that when teaching students about electricity, the students can gain better understanding when they have an opportunity to use the simulation and the real circuits in parallel than if they have only the real circuits or only a computer simulation available, even when the use of the simulation is supported with the explicit instruction. The outcomes of the empirical studies can be considered as the first unambiguous evidence on the (additional) benefits of combining laboratory and simulation activities in science education as compared to learning with laboratories and simulations alone.

Testing and simulation of fractionary electromechanical rotative drives

This paper concerns the development of drives that use electromechanical rotative motor systems. It is proposed an experimental drive test structure integrated to simulation softwares. The objective of this work is to show that an affordable model validation procedure can be obtained by combining a precision data acquisition with well tuned state-of-the-art simulation packages. This is required for fitting, in the best way, a drive to its load or, inversely, to adapt loads to given drive characteristics.

Simulation of new p-type pixel strip detector with enhanced multiplication effect

This Master’s Thesis is dedicated to the simulation of new p-type pixel strip detector with enhanced multiplication effect. It is done for high-energy physics experiments upgrade such as Super Large Hadron Collider especially for Compact Muon Solenoid particle track silicon detectors. These detectors are used in very harsh radiation environment and should have good radiation hardness. The device engineering technology for developing more radiation hard particle detectors is used for minimizing the radiation degradation. New detector structure with enhanced multiplication effect is proposed in this work. There are studies of electric field and electric charge distribution of conventional and new p-type detector under reverse voltage bias and irradiation. Finally, the dependence of the anode current from the applied cathode reverse voltage bias under irradiation is obtained in this Thesis. For simulation Silvaco Technology Computer Aided Design software was used. Athena was used for creation of doping profiles and device structures and Atlas was used for getting electrical characteristics of the studied devices. The program codes for this software are represented in Appendixes.

Transient current technique simulation of semiconductor detectors

Nowadays advanced simulation technologies of semiconductor devices occupies an important place in microelectronics production process. Simulation helps to understand devices internal processes physics, detect new effects and find directions for optimization. Computer calculation reduces manufacturing costs and time. Modern simulation suits such as Silcaco TCAD allow simulating not only individual semiconductor structures, but also these structures in the circuit. For that purpose TCAD include MixedMode tool. That tool can simulate circuits using compact circuit models including semiconductor structures with their physical models. In this work, MixedMode is used for simulating transient current technique setup, which include detector and supporting electrical circuit. This technique was developed by RD39 collaboration project for investigation radiation detectors radiation hard properties.

Development of Generic Simulation Model for Mobile Working Machines

This master’s thesis has been done for Drive! –project in which a new electric motor solution for mobile working machines is developed. Generic simulation model will be used as marketing and development tool. It can be used to model a wide variety of different vehicles with and without electric motor and to show customer the difference between traditionally build vehicles and those with new electric motor solution. Customers can also use simulation model to research different solutions for their own vehicles. At the start of the project it was decided that MeVEA software would be used as main simulation program and Simulink will only be used to simulate the operation of electrical components. Development of the generic model started with the research of these two software applications, simulation models which are made with them and how these simulation models can be build faster. Best results were used for building of generic simulation model. Finished generic model can be used to produce new tractor models for real-time simulations in short notice. All information about model is collected to one datasheet which can be easily filled by the user. After datasheet is filled a script will automatically build new simulation model in seconds. At the moment generic model is capable of building simulation models for wide variety of different tractors but it can be easily altered for other vehicle types too which would also benefit greatly from electric drive solution. Those could be for example wheel loaders and harvesters.

Novel virtual environment and real-time simulation based methods for improving life-cycle efficiency of non-road mobile machinery

Virtual environments and real-time simulators (VERS) are becoming more and more important tools in research and development (R&D) process of non-road mobile machinery (NRMM). The virtual prototyping techniques enable faster and more cost-efficient development of machines compared to use of real life prototypes. High energy efficiency has become an important topic in the world of NRMM because of environmental and economic demands. The objective of this thesis is to develop VERS based methods for research and development of NRMM. A process using VERS for assessing effects of human operators on the life-cycle efficiency of NRMM was developed. Human in the loop simulations are ran using an underground mining loader to study the developed process. The simulations were ran in the virtual environment of the Laboratory of Intelligent Machines of Lappeenranta University of Technology. A physically adequate real-time simulation model of NRMM was shown to be reliable and cost effective in testing of hardware components by the means of hardware-in-the-loop (HIL) simulations. A control interface connecting integrated electro-hydraulic energy converter (IEHEC) with virtual simulation model of log crane was developed. IEHEC consists of a hydraulic pump-motor and an integrated electrical permanent magnet synchronous motorgenerator. The results show that state of the art real-time NRMM simulators are capable to solve factors related to energy consumption and productivity of the NRMM. A significant variation between the test drivers is found. The results show that VERS can be used for assessing human effects on the life-cycle efficiency of NRMM. HIL simulation responses compared to that achieved with conventional simulation method demonstrate the advances and drawbacks of various possible interfaces between the simulator and hardware part of the system under study. Novel ideas for arranging the interface are successfully tested and compared with the more traditional one. The proposed process for assessing the effects of operators on the life-cycle efficiency will be applied for wider group of operators in the future. Driving styles of the operators can be analysed statistically from sufficient large result data. The statistical analysis can find the most life-cycle efficient driving style for the specific environment and machinery. The proposed control interface for HIL simulation need to be further studied. The robustness and the adaptation of the interface in different situations must be verified. The future work will also include studying the suitability of the IEHEC for different working machines using the proposed HIL simulation method.

Diffusive transport properties in monovalent and divalent metal-ion halide melts: A computer simulation study

Self- and cross-velocity correlation functions and related transport coefficients of molten salts are studied by molecular-dynamics simulation. Six representative systems are considered, i.e., NaCl and KCl alkali halides, CuCl and CuBr noble-metal halides, and SrCl2 and ZnCl2 divalent metal-ion halides. Computer simulation results are compared with experimental self-diffusion coefficients and electrical conductivities. Special attention is paid to dynamic cross correlations and their dependence on the Coulomb interactions as well as on the size and mass differences between anions and cations.

Thermal Impacts on Building Integrated Photovoltaic (BIPV) (Electrical, Thermal and Mechanical Characteristics)

Ein Drittel des weltweiten gesamten Energiebedarfs wird durch Gebäude verbraucht. Um diesen Energiebedarf teilweise zu decken, den erheblichen Energieverbrauch zu reduzieren und weiterhin andere Gebäudefunktionen beizubehalten, ist Gebäudeintegrierte Photovoltaik (BIPV) eine der am besten geeigneten Lösungen für die Gebäudenanwendung. Im Bezug auf eine Vielzahl von Gestalltungsmöglichkeiten, sind die Randbedingungen der BIPV-Anwendungen eindeutig anders im Vergleich zu Standard-PV-Anwendungen, insbesondere bezüglich der Betriebstemperatur. Bisher gab es nicht viele Informationen zu den relevanten thermischen Auswirkungen auf die entsprechenden elektrischen Eigenschaften zusammen mit thermischen und mechanischen relevanten Gebäudenfunktionen. Die meisten Hersteller übernehmen diese Eigenschaften von entsprechenden PV-Modulen und konventionellen Bauprodukten Normen, die zur ungenauen System- und Gebäudeplanungen führen. Deshalb ist die Untersuchung des thermischen Einflusses auf elektrische, thermische sowie mechanische Eigenschaften das Hauptziel der vorliegenden Arbeit. Zunächst wird das Temperatur-Model mit dem Power-Balance-Konzept erstellt. Unter Berücksichtigung der variablen Installationsmöglichkeiten und Konfigurationen des Moduls wird das Model auf Basis dynamischer und stationär Eigenschaften entwickelt. Im Hinblick auf die dynamische Simulation können der Energieertrag und Leistung zusammen mit der thermischen Gebäudesimulation in Echtzeit simuliert werden. Für stationäre Simulationen können die relevanten Gebäudefunktionen von BIPV-Modulen sowohl im Sommer als auch im Winter simuliert werden. Basierend auf unterschiedlichen thermischen und mechanischen Last-Szenarien wurde darüber hinaus das mechanische Model zusammen mit Variationen von Belastungsdauer, Montagesystem und Verkapselungsmaterialien entwickelt. Um die Temperatur- und Mechanik-Modelle zu validieren, wurden die verschiedenen Prüfeinrichtungen zusammen mit neuen Testmethoden entwickelt. Bei Verwendung der Prüfanlage „PV variable mounting system“ und „mechanical testing equipment“ werden zudem die verschiedenen Szenarien von Montagesystemen, Modul-Konfigurationen und mechanischen Belastungen emuliert. Mit der neuen Testmethode „back-bias current concept“ können zum einen die solare Einstrahlung und bestimmte Betriebstemperaturen eingestellt werden. Darüber hinaus wurden mit den eingangs erwähnten validierten Modellen das jeweilige elektrische, thermische und mechanische Verhalten auf andere Konfigurationen bewertet. Zum Abschluss wird die Anwendung von Software-Tools bei PV-Herstellern im Hinblick auf die entsprechenden Modellentwicklungen thematisiert.

Numerical Simulation of Electroosmotic Flow with Step Change in Zeta Potential

Electroosmotic flow is a convenient mechanism for transporting polar fluid in a microfluidic device. The flow is generated through the application of an external electric field that acts on the free charges that exists in a thin Debye layer at the channel walls. The charge on the wall is due to the chemistry of the solid-fluid interface, and it can vary along the channel, e.g. due to modification of the wall. This investigation focuses on the simulation of the electroosmotic flow (EOF) profile in a cylindrical microchannel with step change in zeta potential. The modified Navier-Stoke equation governing the velocity field and a non-linear two-dimensional Poisson-Boltzmann equation governing the electrical double-layer (EDL) field distribution are solved numerically using finite control-volume method. Continuities of flow rate and electric current are enforced resulting in a non-uniform electrical field and pressure gradient distribution along the channel. The resulting parabolic velocity distribution at the junction of the step change in zeta potential, which is more typical of a pressure-driven velocity flow profile, is obtained.

Discrete demand side control performance under dynamic building simulation: a heat pump application

This study presents the findings of applying a Discrete Demand Side Control (DDSC) approach to the space heating of two case study buildings. High and low tolerance scenarios are implemented on the space heating controller to assess the impact of DDSC upon buildings with different thermal capacitances, light-weight and heavy-weight construction. Space heating is provided by an electric heat pump powered from a wind turbine, with a back-up electrical network connection in the event of insufficient wind being available when a demand occurs. Findings highlight that thermal comfort is maintained within an acceptable range while the DDSC controller maintains the demand/supply balance. Whilst it is noted that energy demand increases slightly, as this is mostly supplied from the wind turbine, this is of little significance and hence a reduction in operating costs and carbon emissions is still attained.

A combined engineering and statistical model of UK domestic appliance electrical load profiles

The development of a combined engineering and statistical Artificial Neural Network model of UK domestic appliance load profiles is presented. The model uses diary-style appliance use data and a survey questionnaire collected from 51 suburban households and 46 rural households during the summer of 2010 and2011 respectively. It also incorporates measured energy data and is sensitive to socioeconomic, physical dwelling and temperature variables. A prototype model is constructed in MATLAB using a two layer feed forward network with back propagation training which has a 12:10:24 architecture. Model outputs include appliance load profiles which can be applied to the fields of energy planning (microrenewables and smart grids), building simulation tools and energy policy.