论文标题
保守的不连续的Galerkin方案的陀螺仪平均Dougherty碰撞操作员
Conservative discontinuous Galerkin scheme of a gyro-averaged Dougherty collision operator
论文作者
论文摘要
提出了一种保守的不连续的Galerkin方案，用于在全f长波长陀螺仪中进行非线性Dougherty碰撞操作员。在分析上，该模型运营商具有Fokker-Planck运算符的对流形式，它具有非压降熵功能，并且可以保留颗粒，动量和能量。这些保守的特性离散地完全保持不变，与数值分辨率无关。在这项工作中，相位空间离散化是使用不连续的Galerkin方案的新版本进行的，该方案使用弱相等性和恢复的概念精心构造。离散时间的进步是通过明确的时间步变算法进行的，我们探索了其稳定性限制。长波长陀螺仪求解器内的配方和实现通过松弛测试，碰撞的Landau阻尼基准测试以及对螺旋开放野外线的5D旋转湍流的研究进行了验证。
A conservative discontinuous Galerkin scheme for a nonlinear Dougherty collision operator in full-f long-wavelength gyrokinetics is presented. Analytically this model operator has the advective-diffusive form of Fokker-Planck operators, it has a non-decreasing entropy functional, and conserves particles, momentum and energy. Discretely these conservative properties are maintained exactly as well, independent of numerical resolution. In this work the phase space discretization is performed using a novel version of the discontinuous Galerkin scheme, carefully constructed using concepts of weak equality and recovery. Discrete time advancement is carried out with an explicit time-stepping algorithm, whose stability limits we explore. The formulation and implementation within the long-wavelength gyrokinetic solver of Gkeyll are validated with relaxation tests, collisional Landau-damping benchmarks and the study of 5D gyrokinetic turbulence on helical, open field lines.
