The ad-hoc description of anomalous transport through diffusive relations with manually tuned coefficients is currently one of the main limitations in mean-field plasma edge codes, seriously restricting their interpretive and predictive capabilities. In this paper, we attempt to improve that description by relating the anomalous transport coefficients to the turbulent kinetic energy $\kappa$κ$\kappa$ as a measure for the local intensity of the turbulence. Using RANS techniques from hydrodynamic turbulence and insights from their recent successful application to 2D electrostatic $E\times B$E×B$E\times B$ drift turbulence modelling for the scrape-off layer, we propose a transport equation for $\kappa$κ$\kappa$ and discuss its coupling with the mean-field transport equations. The main features of the model include (a) an analytically exact interchange source of $\kappa$κ$\kappa$ which introduces the ballooning character of the transport; (b) fast parallel transport of $\kappa$κ$\kappa$ through the connection with parallel current fluctuations; and (c) consistent transport reduction due to the impact of mean $E\times B$E×B$E\times B$ flow shear. The resulting model has been implemented in the new extended grids version of SOLPS-ITER, enabling for the first time mean-field simulations self-consistently combining classical parallel transport with mean-field drifts and anomalous transport with the code. A first assessment of the model has been made for a representative C-Mod case study, highlighting the promising features of the model. Further analysis is needed to investigate in detail the impact of the different new terms in the model across operational regimes, and determine the new closures constants based on larger sets of turbulence simulations and experimental data.

中文翻译：

---

刮除层中静电、交换主导的 E × B 漂移湍流引起的异常输运的自洽 κ-模型和在 SOLPS-ITER 中的实现

目前，通过手动调整系数的扩散关系对异常传输的特别描述是平均场等离子体边缘代码的主要限制之一，严重限制了它们的解释和预测能力。在本文中，我们试图通过将异常输运系数与湍动能联系起来来改进该描述$\kappa$κ$\kappa$作为局部湍流强度的度量。使用来自流体动力湍流的 RANS 技术和他们最近成功应用于 2D 静电的见解$乙\times 乙$乙×乙$E\times B$对于刮除层的漂移湍流建模，我们提出了一个传输方程$\kappa$κ$\kappa$并讨论它与平均场传输方程的耦合。该模型的主要特征包括 (a) 分析精确的交换源$\kappa$κ$\kappa$这引入了运输的气球特性；(b) 快速平行运输$\kappa$κ$\kappa$通过与并联电流波动的连接；(c) 由于均值的影响，运输量持续减少$乙\times 乙$乙×乙$E\times B$流动剪切。生成的模型已在新的扩展网格版本 SOLPS-ITER 中实现，首次实现平均场模拟自洽地将经典平行传输与平均场漂移和异常传输与代码相结合。已针对具有代表性的 C-Mod 案例研究对该模型进行了首次评估，突出了该模型的有希望的特征。需要进一步分析以详细研究模型中不同新项在运行状态下的影响，并根据更大的湍流模拟和实验数据集确定新的闭合常数。