Download or read book Numerical Tokamak Turbulence Project OFES Grand Challenge written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary research objective of the Numerical Tokamak Turbulence Project (NTTP) is to develop a predictive ability in modeling turbulent transport due to drift-type instabilities in the core of tokamak fusion experiments, through the use of three-dimensional kinetic and fluid simulations and the derivation of reduced models.
Download or read book Numerical Tokamak Turbulence Project written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary research objective of the Numerical Tokamak Turbulence Project (NTTP) is to develop a predictive ability in modeling turbulent transport due to drift-type instabilities in the core of tokamak fusion experiments, through the use of three-dimensional kinetic and fluid simulations and the derivation of reduced models.
Download or read book The Numerical Tokamak Project NTP Simulation of Turbulent Transport in the Core Plasma written by and published by . This book was released on 1993 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-range goal of the Numerical Tokamak Project (NTP) is the reliable prediction of tokamak performance using physics-based numerical tools describing tokamak physics. The NTP is accomplishing the development of the most advanced particle and extended fluid model's on massively parallel processing (MPP) environments as part of a multi-institutional, multi-disciplinary numerical study of tokamak core fluctuations. The NTP is a continuing focus of the Office of Fusion Energy's theory and computation program. Near-term HPCC work concentrates on developing a predictive numerical description of the core plasma transport in tokamaks driven by low-frequency collective fluctuations. This work addresses one of the greatest intellectual challenges to our understanding of the physics of tokamak performance and needs the most advanced computational resources to progress. We are conducting detailed comparisons of kinetic and fluid numerical models of tokamak turbulence. These comparisons are stimulating the improvement of each and the development of hybrid models which embody aspects of both. The combination of emerging massively parallel processing hardware and algorithmic improvements will result in an estimated 10**2--10**6 performance increase. Development of information processing and visualization tools is accelerating our comparison of computational models to one another, to experimental data, and to analytical theory, providing a bootstrap effect in our understanding of the target physics. The measure of success is the degree to which the experimentally observed scaling of fluctuation-driven transport may be predicted numerically. The NTP is advancing the HPCC Initiative through its state-of-the-art computational work. We are pushing the capability of high performance computing through our efforts which are strongly leveraged by OFE support.
Download or read book Numerical Tokamak Turbulence Calculations on the CRAY T3E written by and published by . This book was released on 1997 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Full cross section calculations of ion-temperature-gradient-driven turbulence with Landau closure are being carried out as part of the Numerical Tokamak Turbulence Project, one of the U.S. Department of Energy's Phase II Grand Challenges. To include the full cross section of a magnetic fusion device like the tokamak requires more memory and CPU time than is available on the National Energy Research Scientific Computing Center's (NERSC's) shared-memory vector machines such as the CRAY C90 and J90. Calculations of cylindrical multi-helicity ion-temperature-gradient-driven turbulence were completed on NERSC's 160-processor distributed-memory CRAY T3E parallel computer with 256 Mbytes of memory per processor. This augurs well for yet more memory and CPU intensive calculations on the next-generation T3E at NERSC. This paper presents results on benchmarks with the current T3E at NERSC. Physics results pertaining to plasma confinement at the core of tokamaks subject to ion-temperature-gradient-driven-turbulence are also highlighted. Results at this resolution covering this extent of physical time were previously unattainable. Work is in progress to increase the resolution, improve the performance of the parallel code, and include toroidal geometry in these calculations in anticipation of the imminent arrival of a fully configured,512-processor, T3E-900 model.
Download or read book Numerical Simulation of Tokamak Plasma Turbulence and Internal Transport Barriers written by A. Thyagaraja and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulations of Tokamak Plasma Turbulence and Internal Transport Barriers written by A. Thyagaraja and published by . This book was released on 2000 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Numerical Simulations of Turbulence and Transport in a Tokamak written by A. Thyagaraja and published by . This book was released on 1996 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Numerical Simulations of Long wavelength Tokamak Turbulence and Transport Using CUTIE Electrostatic Nonadiabaticity Model written by A. Thyagaraja and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Numerical Simulations of Long wavelength Tokamak Turbulence and Transport Using CUTIE electrostatic Nonadiabatcity Model written by A. Thyagaraja and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Model Reduction for Tokamak Plasma Turbulence written by Camille Gillot and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimal control of tokamak plasmas requires efficient and accurate prediction of heat and matter transport. Growing from kinetic resonant instabilities, turbulence saturates by involving many scales, from the small vortex up to the back-reaction on the density and temperature profiles. Self-organisation processes are of particular interest, encompassing spontaneous zonal flow genera- tion and transport by avalanche. First principle numerical simulation codes like GYSELA allow studying the gyro-kinetic evolution of the particle distribution function. The large model size and cost prompts the need for reduction. Removing velocity dimensions is the so-called collisionless closure problem for fluid equations. Earlier approaches are extended and generalised by calling to the dynamical systems and optimal control litterature. In particular, we apply the balanced truncation and rational interpolation to the one-dimensional linear VlasovPoisson problem. The interpolation method features a cheap and versatile formulation, opening the door to wider use for more complex phenomena. Quasi-linear theory is the reference model for turbulent effects. The GYSELA three-dimensional output is analysed to estimate the robustness of linear properties in turbulent filaments. Key quasi-linear quantities carry over to the non-linear regime. Effective velocities and shape of turbulent structures are computed, and match expected group velocities and linear eigenmode. Nevertheless, the turbulent potential spectrum must be specified externally to quasi- linear models. This results in radially travelling unstable linear solutions that share many properties of turbulent avalanches seen in numerical simulations.
Download or read book New Ideas in Tokamak Confinement written by Marshall N. Rosenbluth and published by Springer Science & Business Media. This book was released on 1997-05-08 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Market: Scientists and students involved in thermonuclear fusion research. Thermonuclear fusion research using the confinement device tokamak represents one of the most prominent science projects in the second half of the 20th century. International Tokamak Community is now committing significant effort and funds to experiments with burning plasma, hot and dense enough to produce significant nuclear fusion reactions. The methods used to enhance tokamak performance have a profound and immediate effect on machine design. This book provides an up-to-date account of research in tokamak fusion and puts forward innovative ideas in confinement physics.
Download or read book Lecture Series on Turbulent Transport in Tokamaks written by Ronald E. Waltz and published by . This book was released on 1987 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parallel Processing and Applied Mathematics written by Roman Wyrzykowski and published by Springer. This book was released on 2003-08-01 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed post-proceedings of the 4th International Conference on Parallel Processing and Applied Mathematics, PPAM 2002, held in Naleczow, Poland, in September 2001. The 101 papers presented were carefully reviewed and improved during two rounds of reviewing and revision. The book offers topical sections on distributed and grid architectures, scheduling and load balancing, performance analysis and prediction, parallel non-numerical algorithms, parallel programming, tools and environments, parallel numerical algorithms, applications, and evolutionary computing and neural networks.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gyrokinetic Simulation of Global Turbulent Transport Properties in Tokamak Experiments written by and published by . This book was released on 2006 with total page 92505 pages. Available in PDF, EPUB and Kindle. Book excerpt: A general geometry gyro-kinetic model for particle simulation of plasma turbulence in tokamak experiments is described. It incorporates the comprehensive influence of noncircular cross section, realistic plasma profiles, plasma rotation, neoclassical (equilibrium) electric fields, and Coulomb collisions. An interesting result of global turbulence development in a shaped tokamak plasma is presented with regard to nonlinear turbulence spreading into the linearly stable region. The mutual interaction between turbulence and zonal flows in collisionless plasmas is studied with a focus on identifying possible nonlinear saturation mechanisms for zonal flows. A bursting temporal behavior with a period longer than the geodesic acoustic oscillation period is observed even in a collisionless system. Our simulation results suggest that the zonal flows can drive turbulence. However, this process is too weak to be an effective zonal flow saturation mechanism.
Download or read book State of the Laboratory written by William A. Bookless and published by DIANE Publishing. This book was released on 1995-11 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights the Laboratory's 1994 accomplishments in their mission areas and core programs -- economic competitiveness, national security, lasers, energy, the environment, biology and biotechnology, engineering, physics and space science, chemistry and materials science, computations, and science and math education.
