716 research outputs found

    Development of an Intelligent Monitoring and Control System for a Heterogeneous Numerical Propulsion System Simulation

    Get PDF
    The NASA Numerical Propulsion System Simulation (NPSS) project is exploring the use of computer simulation to facilitate the design of new jet engines. Several key issues raised in this research are being examined in an NPSS-related research project: zooming, monitoring and control, and support for heterogeneity. The design of a simulation executive that addresses each of these issues is described. In this work, the strategy of zooming, which allows codes that model at different levels of fidelity to be integrated within a single simulation, is applied to the fan component of a turbofan propulsion system. A prototype monitoring and control system has been designed for this simulation to support experimentation with expert system techniques for active control of the simulation. An interconnection system provides a transparent means of connecting the heterogeneous systems that comprise the prototype

    Planets Transiting Non-Eclipsing Binaries

    Full text link
    The majority of binary stars do not eclipse. Current searches for transiting circumbinary planets concentrate on eclipsing binaries, and are therefore restricted to a small fraction of potential hosts. We investigate the concept of finding planets transiting non-eclipsing binaries, whose geometry would require mutually inclined planes. Using an N-body code we explore how the number and sequence of transits vary as functions of observing time and orbital parameters. The concept is then generalised thanks to a suite of simulated circumbinary systems. Binaries are constructed from RV surveys of the solar neighbourhood. They are then populated with orbiting gas giants, drawn from a range of distributions. The binary population is shown to be compatible with the Kepler eclipsing binary catalogue, indicating that the properties of binaries may be as universal as the initial mass function. These synthetic systems produce transiting circumbinary planets occurring on both eclipsing and non-eclipsing binaries. Simulated planets transiting eclipsing binaries are compared with published Kepler detections. We obtain 1) that planets transiting non-eclipsing binaries probably exist in the Kepler data, 2) that observational biases alone cannot account for the observed over-density of circumbinary planets near the stability limit, implying a physical pile-up, and 3) that the distributions of gas giants orbiting single and binary stars are likely different. Estimating the frequency of circumbinary planets is degenerate with the spread in mutual inclination. Only a minimum occurrence rate can be produced, which we find to be compatible with 9%. Searching for inclined circumbinary planets may significantly increase the population of known objects and will test our conclusions. Their existence, or absence, will reveal the true occurrence rate and help develop circumbinary planet formation theories.Comment: 19 pages, 14 figures, accepted August 2014 to A&A, minor changes to previous arXiv versio

    Higher Level Modeling in RESQME

    Get PDF
    RC 13554 (#60544) The RESearch Queueing Package Modeling Environment (RESQME) is a graphical workstation environment for iteratively constructing, running and analyzing models of resource contention systems. It is built on top of the RESearch Queueing Package (RESQ) which provides the functionality to evaluate extended queueing networks. In this paper we describe the high-level building component design for RESQME. The modeler is provided with tools to create his own icons and to associate them with submodels. He then uses ilicsc building blocks to construct his model. This capability extends the funtlaiiicnlal building blocks of RESQ and allows the user to create models with objccls directly related to his application domain

    Efficient Generating And Processing Of Large-Scale Unstructured Meshes

    Get PDF
    Unstructured meshes are used in a variety of disciplines to represent simulations and experimental data. Scientists who want to increase accuracy of simulations by increasing resolution must also increase the size of the resulting dataset. However, generating and processing a extremely large unstructured meshes remains a barrier. Researchers have published many parallel Delaunay triangulation (DT) algorithms, often focusing on partitioning the initial mesh domain, so that each rectangular partition can be triangulated in parallel. However, the comproblems for this method is how to merge all triangulated partitions into a single domain-wide mesh or the significant cost for communication the sub-region borders. We devised a novel algorithm --Triangulation of Independent Partitions in Parallel (TIPP) to deal with very large DT problems without requiring inter-processor communication while still guaranteeing the Delaunay criteria. The core of the algorithm is to find a set of independent} partitions such that the circumcircles of triangles in one partition do not enclose any vertex in other partitions. For this reason, this set of independent partitions can be triangulated in parallel without affecting each other. The results of mesh generation is the large unstructured meshes including vertex index and vertex coordinate files which introduce a new challenge \-- locality. Partitioning unstructured meshes to improve locality is a key part of our own approach. Elements that were widely scattered in the original dataset are grouped together, speeding data access. For further improve unstructured mesh partitioning, we also described our new approach. Direct Load which mitigates the challenges of unstructured meshes by maximizing the proportion of useful data retrieved during each read from disk, which in turn reduces the total number of read operations, boosting performance

    Enhancing Mesh Deformation Realism: Dynamic Mesostructure Detailing and Procedural Microstructure Synthesis

    Get PDF
    Propomos uma solução para gerar dados de mapas de relevo dinâmicos para simular deformações em superfícies macias, com foco na pele humana. A solução incorpora a simulação de rugas ao nível mesoestrutural e utiliza texturas procedurais para adicionar detalhes de microestrutura estáticos. Oferece flexibilidade além da pele humana, permitindo a geração de padrões que imitam deformações em outros materiais macios, como couro, durante a animação. As soluções existentes para simular rugas e pistas de deformação frequentemente dependem de hardware especializado, que é dispendioso e de difícil acesso. Além disso, depender exclusivamente de dados capturados limita a direção artística e dificulta a adaptação a mudanças. Em contraste, a solução proposta permite a síntese dinâmica de texturas que se adaptam às deformações subjacentes da malha de forma fisicamente plausível. Vários métodos foram explorados para sintetizar rugas diretamente na geometria, mas sofrem de limitações como auto-interseções e maiores requisitos de armazenamento. A intervenção manual de artistas na criação de mapas de rugas e mapas de tensão permite controle, mas pode ser limitada em deformações complexas ou onde maior realismo seja necessário. O nosso trabalho destaca o potencial dos métodos procedimentais para aprimorar a geração de padrões de deformação dinâmica, incluindo rugas, com maior controle criativo e sem depender de dados capturados. A incorporação de padrões procedimentais estáticos melhora o realismo, e a abordagem pode ser estendida além da pele para outros materiais macios.We propose a solution for generating dynamic heightmap data to simulate deformations for soft surfaces, with a focus on human skin. The solution incorporates mesostructure-level wrinkles and utilizes procedural textures to add static microstructure details. It offers flexibility beyond human skin, enabling the generation of patterns mimicking deformations in other soft materials, such as leater, during animation. Existing solutions for simulating wrinkles and deformation cues often rely on specialized hardware, which is costly and not easily accessible. Moreover, relying solely on captured data limits artistic direction and hinders adaptability to changes. In contrast, our proposed solution provides dynamic texture synthesis that adapts to underlying mesh deformations. Various methods have been explored to synthesize wrinkles directly to the geometry, but they suffer from limitations such as self-intersections and increased storage requirements. Manual intervention by artists using wrinkle maps and tension maps provides control but may be limited to the physics-based simulations. Our research presents the potential of procedural methods to enhance the generation of dynamic deformation patterns, including wrinkles, with greater creative control and without reliance on captured data. Incorporating static procedural patterns improves realism, and the approach can be extended to other soft-materials beyond skin

    Modeling and simulation of the heat storage of a solar district heating plant

    Get PDF
    The aim of this study is to evaluate the long term performance of the water pit heat storage of the Dronninglund solar district heating plant in Denmark, located in the peninsula of Jutland. Experimental storage data from 2017 is evaluated, including the charged and discharged energy, its efficiency, the diffusers outlet temperatures, envelope heat losses and many more. In addition, simulation of different models are carried out based on Type 1535 and 1301 elements of TRNSYS, developed by TESS. The objective of these simulations is to analyze not only the long term performance of the storage, but the accuracy that the results have compared with the actual data. The differences between models are the number of layers in which the storage is divided, changes in geometry or modifications in soil properties to study how these changes affect to the performance of the storage. The results show that the models simulate with a pretty high accuracy the outlet temperatures of the storage, especially the ones from the top and bottom diffusers. The actual charged and discharged energy of the year in question is 11868 MWh and 11250 MWh, respectively. The simulations show a high accuracy in terms of charged energy, with only a -3% deviation in the worst case. Although the discharged energy is not as accurate as the charged energy, the results are quite acceptable. Total heat losses of the real storage have a value of 1157 MWh. The results of all models are deviate significantly from the actual value, both overestimated and underestimated, but the possible reasons are explained throughout this report. However, the distribution of the different types of heat losses among all models results in about 65% of top losses, 33% of edge losses and 2% of bottom losses, except in the model where the soil properties are modified, with a different percentage distribution. The same applies for the efficiency of the storage, whose actual value is 90%. The simulated efficiency values are higher for the models that with lower heat losses and lower values for the model with higher heat losses with respect to the real tank, since they are dependent parameters between them. This study serves to draw some initial conclusions about how Type 1535 and Type 1301 perform as the water pit heat storage of DronninglundObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.2 - Per a 2030, augmentar substancialment el percentatge d’energia renovable en el con­junt de fonts d’energi

    Applications of Simulation and Animation in Facilities Planning and Design

    Get PDF
    Recent developments of simulation software have made computer simulation and animation popular system problem-solving techniques. One field that has many potential applications for computer simulation and animation is in the area of facilities planning and design. The purpose of this paper is to provide the facilities planner with information to assist in determining when, why, how and what simulation software should be implemented to solve facilities planning and design problems. Also, the usefulness of simulation and animation to the facilities planner is evaluated and areas for improving software for future application in facilities planning and design are identified. TO assist in presenting these objectives, a sample facilities planning and design problem is modeled with Cinema software to illustrate the model-building process as well as the characteristics of simulation and animation software

    Safe and Sound: Proceedings of the 27th Annual International Conference on Auditory Display

    Get PDF
    Complete proceedings of the 27th International Conference on Auditory Display (ICAD2022), June 24-27. Online virtual conference
    • …
    corecore