Development of a new THINC/WLIC method based on a separate evaluation of the geometrical fidelity and the interface sharpness

Fukuda, Takanari; Yamashita, Susumu; Yoshida, Hiroyuki

Journal of Computational Physics, 545, p.114485_1 - 114485_32, 2026/01

https://doi.org/10.1016/j.jcp.2025.114485

This paper puts forward a novel approach for the evaluation of the geometrical fidelity and the interface sharpness of the VOF advection schemes separately and quantitatively. This new evaluation has elucidated the trade-off relationship of the geometrical fidelity and the interface sharpness between the existing schemes of the original THINC and the THINC/WLIC. By investigating and resolving this trade-off relationship, we have developed a novel THINC-based scheme that exhibits high performance with regard to both geometrical fidelity and interface sharpness, despite employing an algorithm as concise as those of the original THINC and the THINC/WLIC. The novel scheme, designated "THINC/Advanced WLIC (THINC/AWLIC)," has been developed by redefining the weight function of the preceding THINC/WLIC so that the contribution of the first-order upwind flux can be variably blended with the usage of the control parameter. The results of the multiple benchmark tests in two and three dimensions demonstrate that both the geometrical fidelity and the interface sharpness are significantly enhanced if the control parameter is appropriately determined. Furthermore, the associated error of THINC/AWLIC is comparable to that of the geometrical scheme, although the implementation complexity is unchanged from that of the simple THICN/WLIC.

A New hybrid kinetic electron model for full-f gyrokinetic simulations

Idomura, Yasuhiro

Journal of Computational Physics, 313, p.511 - 531, 2016/05

https://doi.org/10.1016/j.jcp.2016.02.057

A new hybrid kinetic electron model is developed for electrostatic full-f gyrokinetic simulations of the ion temperature gradient driven trapped electron mode (ITG-TEM) turbulence at the ion scale. In the model, a full kinetic electron model is applied to the full-f gyrokinetic equation, the multi-species linear Fokker-Planck collision operator, and an axisymmetric part of the gyrokinetic Poisson equation, while in a non-axisymmetric part of the gyrokinetic Poisson equation, turbulent fluctuations are determined only by kinetic trapped electrons responses. By using this approach, the so-called mode is avoided with keeping important physics such as the ITG-TEM, the neoclassical transport, the ambipolar condition, and particle trapping and detrapping processes. The model enables full- f gyrokinetic simulations of ITG-TEM turbulence with a reasonable computational cost.

A High-precision calculation method for interface normal and curvature on an unstructured grid

Ito, Kei; Kunugi, Tomoaki*; Ohno, Shuji; Kamide, Hideki; Ohshima, Hiroyuki

Journal of Computational Physics, 273, p.38 - 53, 2014/09

https://doi.org/10.1016/j.jcp.2014.04.058

Dynamic transport simulation code including plasma rotation and radial electric field

Honda, Mitsuru; Fukuyama, Atsushi*

Journal of Computational Physics, 227(5), p.2808 - 2844, 2008/02

https://doi.org/10.1016/j.jcp.2007.11.017

A Note on the basis set approach in the constrained interpolation profile method

Utsumi, Takayuki*; Yabe, Takashi*; Koga, J. K.; Aoki, Takayuki*; Sekine, Masatoshi*; Ogata, Yoichi*; Matsunaga, Eiichi*

Journal of Computational Physics, 196(1), p.1 - 7, 2004/05

https://doi.org/10.1016/j.jcp.2003.10.019

no abstracts in English