Interchange Turbulence Model for the Edge Plasma in SOLEDGE2D‐EIRENE

In this paper, a κ−ϵ transport model is presented as a turbulence reduction tool for a typical ohmic L‐mode discharge plasma in a divertor‐configurated tokamak. Taking a Tokamak à configuration variable (TCV) study case, a feedback loop procedure is performed using the SolEdge2D code to acquire plasma diffusivity at the outer mid‐plane. The κ−ϵ model is calibrated through its free parameters with the aim of recovering the diffusivity calculated in the feedback procedure. Finally, it is shown that the model can self‐consistently calculate diffusivity in the whole domain, recovering the poloidal asymmetries due to interchange instabilities.

“…In this paper, we follow the approach proposed in ref. , where a reduced model inspired by the κ − ϵ approach has been applied to the transport code SolEdge2D‐Eirene.…”

Section: A κ−ε Model For Turbulent Diffusivitymentioning

confidence: 99%

“…Transport diffusivities are derived from the turbulence intensity according to the expression proposed in ref. :

D_{κ ϵ} = \frac{R}{c_{normals}} \cdot κ = \frac{1}{Δ ω} \cdot ((), γ_{0} \sqrt{\frac{R}{λ_{normalp}} - Θ} + β T_{e}^{2}) .

…”

Section: A κ−ε Model For Turbulent Diffusivitymentioning

confidence: 99%

Section: Reduction and Optimization Of The Degrees Of Freedom Of The mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optimization of turbulence reduced model free parameters based on L‐mode experiments and 2D transport simulations

Baschetti

Bufferand

Ciraolo

et al. 2018

“…Heat flux calculations presently rely on transport codes, which are a combination of two‐dimensional (2D) fluid codes for charged particles and a kinetic Monte Carlo code modelling the neutral species behaviour as well as their interaction with the background plasma (e.g., SOLPS, SOLEDGE2D‐EIRENE, EDGE2D). All these codes solve mean‐field equations in which the gradient diffusion hypothesis is applied to model turbulent fluxes . However, so far the anomalous transport coefficients introduced through this procedure are not consistently calculated, and are simply taken as the input parameters of the simulations.…”

Section: Introductionmentioning

confidence: 99%

Self‐consistent coupling of the three‐dimensional fluid turbulence code TOKAM3X and the kinetic neutrals code EIRENE

Fan

Marandet

Tamain

et al. 2018

Self Cite

The three‐dimensional (3D) turbulence code TOKAM3X‐EIRENE, coupling the 3D non‐isothermal version of TOKAM3X to the EIRENE Monte Carlo solver has been developed with the ability to simulate self‐consistently the interactions between large‐scale flows and turbulence both in limited and diverted plasmas, including recycling. This is especially important for diverted plasmas, where neutrals play a key role and where the recycling source is strongly dominant. The code package relies on the same interface as the Soledge2D‐EIRENE code, which retains state‐of‐the‐art plasma–wall interaction, as well as atomic and molecular physics. In this paper, we present the first results obtained in WEST divertor geometry, in laminar mode, with the aim of verifying the new code package. The divertor density regimes are recovered, and the code results are shown to be consistent with the results of the two‐point model, thus opening the way for turbulent simulations.

Interchange‐turbulence‐based radial transport model for SOLPS‐ITER: A COMPASS case study

Carli

Dekeyser

Coosemans

et al. 2020

Mean-field plasma edge transport codes such as SOLPS-ITER heavily rely on adhoc radial diffusion coefficients to approximately model anomalous transport. Such coefficients are experimentally determined and vary between different machines, and also depend on the operational regime and plasma location within the same device. Therefore, to match experimental data the modeler is required to manually tune several free parameters in expensive simulations, and the code's predictive capabilities are significantly downgraded. As a solution, a new model has been developed for SOLPS-ITER, solving an additional transport equation for the turbulent kinetic energy , derived by consistently time-averaging the Braginskii equations, and including a diffusive closure for the anomalous particle flux. This closure model relates the anomalous diffusion coefficient to the local value. The resulting equation structure and its closure are inspired by TOKAM2D isothermal interchange turbulence simulation results. Within this model, fewer and hopefully more universal free parameters are retained, thus improving the code's predictive capabilities. The new model has been tested on a COMPASS case for which upstream plasma profiles were available. Experimental data and a reference solution, obtained by matching the profiles through manual tuning of radial diffusivities, have been used to estimate the parameters of our new transport model. A ballooned particle diffusivity profile is retrieved by the new radial transport model, thanks to the proposed interchange drive. The obtained upstream profiles qualitatively agree with the experiment and prove the new model is a promising first attempt to be further refined.