Validation of edge turbulence codes against the TCV-X21 diverted L-mode reference case
Validation of edge turbulence codes against the TCV-X21 diverted L-mode reference case
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DOI：
10.1088/1741-4326/ac4cde
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发表时间：
2021-09
期刊：
影响因子：
3.3
通讯作者：
D. S. Oliveira;T. Body;D. Galassi;C. Theiler;E. Laribi;P. Tamain;A. Stegmeir;M. Giacomin;W. Zholobenko;P. Ricci;H. Bufferand;J. Boedo;G. Ciraolo;C. Colandrea;David Coster;H. D. Oliveira;G. Fourestey;S. Gorno;F. Imbeaux;F. Jenko;V. Naulin;N. Offeddu;H. Reimerdes;E. Serre;C. Tsui;N. Varini;N. Vianello;M. Wiesenberger;C. Wuthrich;The Tcv Team
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文献类型：
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作者：
D. S. Oliveira;T. Body;D. Galassi;C. Theiler;E. Laribi;P. Tamain;A. Stegmeir;M. Giacomin;W. Zholobenko;P. Ricci;H. Bufferand;J. Boedo;G. Ciraolo;C. Colandrea;David Coster;H. D. Oliveira;G. Fourestey;S. Gorno;F. Imbeaux;F. Jenko;V. Naulin;N. Offeddu;H. Reimerdes;E. Serre;C. Tsui;N. Varini;N. Vianello;M. Wiesenberger;C. Wuthrich;The Tcv Team
对现有托卡马克装置的偏滤器和刮削层进行自洽全尺寸顺磁输运模拟最近已成为可能。这使得湍流模拟与实验测量能够直接进行比较。在这项工作中，我们进行了一系列的转向欧姆L模式放电的托卡马克的配置变量（TCV）托卡马克，建立一个第一的一类数据集的边缘湍流模型的验证。该数据集被称为TCV-X21，包含从外侧中平面（OMP）到偏滤器目标的五个诊断系统的测量结果，在两个环形磁场方向上总共提供了45个一维和二维比较观测值。实验数据被用来验证三个通量驱动的三维流体湍流模型-GBS，GRILLIX和TOKAM 3X。对于每个模型，我们都对TCV-X21方案进行了模拟，分别调整粒子和电源速率，以实现密度和电子温度的上游分界线值的合理匹配。我们发现，模拟匹配的实验配置文件在OMP的最可观的轮廓形状和绝对幅度方面，而一个相对较差的协议被发现对偏滤器目标。模拟和实验之间的匹配被认为是敏感的值的电阻率，导热系数，功率注入率和鞘层边界条件的选择。此外，尽管针对鞘层限制制度，模拟和实验之间的差异也表明，中性动力学应包括在内。该验证的结果表明，湍流模型能够对现有设备进行模拟，并与实验测量值取得合理的一致性。在发现不一致的地方，验证有助于确定如何改进模型。通过公开发布实验数据集和验证分析，这项工作应该有助于指导和加速边缘和SOL的预测湍流模拟的发展。
Self-consistent full-size turbulent-transport simulations of the divertor and scrape-off-layer (SOL) of existing tokamaks have recently become feasible. This enables the direct comparison of turbulence simulations against experimental measurements. In this work, we perform a series of diverted ohmic L-mode discharges on the tokamak à configuration variable (TCV) tokamak, building a first-of-a-kind dataset for the validation of edge turbulence models. This dataset, referred to as TCV-X21, contains measurements from five diagnostic systems from the outboard midplane (OMP) to the divertor targets—giving a total of 45 one- and two-dimensional comparison observables in two toroidal magnetic field directions. The experimental dataset is used to validate three flux-driven 3D fluid-turbulence models—GBS, GRILLIX and TOKAM3X. With each model, we perform simulations of the TCV-X21 scenario, individually tuning the particle and power source rates to achieve a reasonable match of the upstream separatrix value of density and electron temperature. We find that the simulations match the experimental profiles for most observables at the OMP—both in terms of profile shape and absolute magnitude—while a comparatively poorer agreement is found towards the divertor targets. The match between simulation and experiment is seen to be sensitive to the value of the resistivity, the heat conductivities, the power injection rate and the choice of sheath boundary conditions. Additionally, despite targeting a sheath-limited regime, the discrepancy between simulations and experiment also suggests that the neutral dynamics should be included. The results of this validation show that turbulence models are able to perform simulations of existing devices and achieve reasonable agreement with experimental measurements. Where disagreement is found, the validation helps to identify how the models can be improved. By publicly releasing the experimental dataset and validation analysis, this work should help to guide and accelerate the development of predictive turbulence simulations of the edge and SOL.