Author: C. Z. ChengPublisher:
ISBN:
Category :
Languages : en
Pages : 50
Book Description
Numerical Solutions of Magnetohydrodynamic Stability of Axisymmetric Toroidal Plasmas Using Cubic B-spline Finite Element Method
Author: C. Z. ChengNumerical Solutions of Magnetohydrodynamic Stability of Axisymmetric Toroidal Plasmas Using Cubic B-spline Finite Element Method
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A nonvariational ideal MHD stability code (NOVA) has been developed. In a general flux coordinate ([psi], theta, [zeta]) system with an arbitrary Jacobian, the NOVA code employs Fourier expansions in the generalized poloidal angle theta and generalized toroidal angle [zeta] directions, and cubic-B spline finite elements in the radial [psi] direction. Extensive comparisons with these variational ideal MHD codes show that the NOVA code converges faster and gives more accurate results. An extended version of NOVA is developed to integrate non-Hermitian eigenmode equations due to energetic particles. The set of non-Hermitian integro-differential eigenmode equations is numerically solved by the NOVA-K code. We have studied the problems of the stabilization of ideal MHD internal kink modes by hot particle pressure and the excitation of ''fishbone'' internal kink modes by resonating with the energetic particle magnetic drift frequency. Comparisons with analytical solutions show that the values of the critical .beta./sub h/ from the analytical theory can be an order of magnitude different from those computed by the NOVA-K code. 24 refs., 11 figs., 1 tab.
Energy Research Abstracts
Author: Proceedings of the ... International Conference on Finite Element Methods in Flow Problems
Author: Publisher:
ISBN:
Category : Finite element method
Languages : en
Pages : 1624
Book Description
NOVA
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A nonvariational approach for determining the ideal MHD stability of axisymmetric toroidal confinement systems is presented. The code (NOVA) employs cubic B-spline finite elements and Fourier expansion in a general flux coordinate (psi, theta, zeta) system. Better accuracy and faster convergence were obtained in comparison with the variational PEST and ERATO codes. The nonvariational approach can be extended to problems having non-Hermitian eigenmode equations where variational energy principles cannot be obtained.
The Computation of Resistive MHD Instabilities in Axisymmetric Toroidal Plasmas
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 66
Book Description
We describe the linear MHD eigenmode code NOVA-R, which calculates the resistive stability of axisymmetric toroidal equilibria. A formulation has been adopted which accurately resolves the continuum spectrum of the ideal MHD operator. The resistive MHD stability equations are transformed into three coupled second order equations, one of which recovers the equation solved by the NOVA code in the ideal limit. The eigenfunctions are represented by a Fourier expansion and cubic B-spline finite elements which are packed about the internal boundary layer. Accurate results are presented for dimensionless resistivities as low as 10−3° in cylindrical geometry. For axisymmetric toroidal plasmas we demonstrate the accuracy of the NOVA-R code by recovering ideal results in the? 2!0 limit, and cylindrical resistive interchange results in the a/R 2!limit.???????? analysis performed using the eigenfunctions computed by the NOVA-R code agree with the asymptotic matching results from the resistive PEST code for zero beta equilibria. 33 refs., 30 figs.
Government Reports Announcements & Index
Author: Government reports annual index
Author: Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 796
Book Description
Author: