The integral equation approach to kinematic dynamo theory and its application to dynamo experiments in cylindrical geometry
نویسندگان
چکیده
The conventional magnetic induction equation that governs hydromagnetic dynamo action is transformed into an equivalent integral equation system. An advantage of this approach is that the computational domain is restricted to the region occupied by the electrically conducting fluid and to its boundary. This integral equation approach is first employed to simulate kinematic dynamos excited by Beltrami-like flows in a finite cylinder. The impact of externally added layers around the cylinder on the onset of dynamo actions is investigated. Then it is applied to simulate dynamo experiments within cylindrical geometry including the ”von Kármán sodium” (VKS) experiment and the Riga dynamo experiment. A modified version of this approach is utilized to investigate magnetic induction effects under the influence of externally applied magnetic fields which is also important to measure the proximity of a given dynamo facility to the self-excitation threshold.
منابع مشابه
Steady dynamos in finite domains: an integral equation approach
The paper deals with the integral equation approach to steady kinematic dynamo models in finite domains based on Biot-Savart’s law. The role of the electric potential at the boundary is worked out explicitly. As an example, a modified version of the simple spherical α-effect dynamo model proposed by Krause and Steenbeck is considered in which the α-coefficient is no longer constant but may vary...
متن کاملIntegral Equations for Kinematic Dynamo Models
2 S u m m a r y : A new technique for the treatment of the kinematic dynamo problem is presented. The method is applicable when the dynamo is surrounded by a medium of nite conductivity and is based on a reformulation of the induction equation and boundary conditions at innnity into an integral equation. We show that the integral operator ^ I involved here is compact in the case of homogeneous ...
متن کاملEffect of magnetic boundary conditions on the dynamo threshold of von Kármán swirling flows
We study the effect of different boundary conditions on the kinematic dynamo threshold of von Kármán type swirling flows in a cylindrical geometry. Using an analytical test flow, we model different boundary conditions: insulating walls all over the flow, effect of sodium at rest on the cylinder side boundary, effect of sodium behind the impellers, effect of impellers or side wall made of a high...
متن کاملAn Integral Equation Approach to Kinematic Dynamo Models
The paper deals with dynamomodels in which the induction effects act within a bounded region surrounded by an electrically conducting medium at rest. Instead of the induction equation, an equivalent integral equation is considered, which again poses an eigenvalue problem. The eigenfunctions and eigenvalues represent the magnetic field modes and corresponding dynamo numbers. In the simplest case...
متن کاملShear dynamo problem: Quasilinear kinematic theory.
Large-scale dynamo action due to turbulence in the presence of a linear shear flow is studied. Our treatment is quasilinear and kinematic but is nonperturbative in the shear strength. We derive the integrodifferential equation for the evolution of the mean magnetic field by systematic use of the shearing coordinate transformation and the Galilean invariance of the linear shear flow. For nonheli...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- J. Comput. Physics
دوره 227 شماره
صفحات -
تاریخ انتشار 2008