论文标题
调查剪切流通过得克萨斯州Helimak中限制器的连续旋转模拟
Investigating shear flow through continuum gyrokinetic simulations of limiter biasing in the Texas Helimak
论文作者
论文摘要
在德克萨斯州Helimak上进行的限制性偏置实验，这是一种简单的磁性圆环，对流动剪切对湍流水平的影响尚无定论。为了调查这一点，已经进行了使用血浆物理代码gkeyll在HELIMAK中偏置的第一个陀螺仪模拟，并在此提供了结果。对于考虑的情况，湍流主要是由互换不稳定驱动的，这取决于平衡密度曲线的梯度。对实验数据和仿真数据的分析表明，剪切速率大部分小于局部线性生长速率，并且并非满足剪切稳定的所有要求。相反，大部分垂直剪切流对散装运输和实验平衡密度曲线具有重要影响，并且对梯度的变化对应于湍流水平的变化。
Previous limiter-biasing experiments on the Texas Helimak, a simple magnetized torus, have been inconclusive on the effect of flow shear on turbulence levels. To investigate this, the first gyrokinetic simulations of limiter biasing in the Helimak using the plasma physics code Gkeyll have been carried out, and results are presented here. For the scenarios considered, turbulence is mostly driven by the interchange instability, which depends on gradients of equilibrium density profiles. An analysis of both experimental and simulation data demonstrates that shear rates are mostly less than than local linear growth rates, and not all requirements for shear stabilization are met. Rather, the mostly vertical shear flow has an important effect on bulk transport and experimental equilibrium density profiles, and changes to the gradients correspond to changes in turbulence levels.
