Top>Research and Development>Development of THINC/AWLIC method that advects sharp interfaces with simple implementation
Development of THINC/AWLIC method that advects sharp interfaces with simple implementation
In gas-liquid two-phase flow analysis, it is important to track the interface with high accuracy, and interface trapping schemes based on the VOF method are widely used. In particular, while geometric methods such as the PLIC method have high accuracy, the complexity of three-dimensional implementation is an issue. On the other hand, the THINC method and THINC/WLIC method are widely used due to their simple algorithms that do not require geometric reconstruction, but they still have issues such as interface distortion and numerical diffusion.
In this study, we quantitatively evaluated the trade-off relationship between "interface shape reproducibility (geometric accuracy)" and "interface sharpness" in existing THINC system schemes and clarified the cause. Furthermore, to resolve this trade-off, we developed the THINC/Advanced WLIC (THINC/AWLIC) method, which introduces a new weighting function.
In the proposed method, by continuously controlling the contributions of the first-order upwind scheme and the THINC scheme based on the interface normal direction, we achieve accurate transport of the interface shape while suppressing unnecessary numerical diffusion. In particular, we confirmed that by appropriately setting the control parameters, the sharpness of the interface was significantly improved compared to the conventional THINC/WLIC method, and geometric accuracy was also maintained.
Verification on 2D and 3D benchmark problems and complex flow fields showed that the proposed method showed superior interface capture performance compared to conventional methods, and showed that accuracy comparable to the PLIC method can be achieved with a much simpler implementation. Furthermore, we have confirmed its effectiveness when applied to actual multiphase flow simulations.
This research provides a fundamental technology that accelerates the application of CFD to large-scale engineering systems by realizing a highly accurate and easy-to-implement interface capture scheme.
In this study, we quantitatively evaluated the trade-off relationship between "interface shape reproducibility (geometric accuracy)" and "interface sharpness" in existing THINC system schemes and clarified the cause. Furthermore, to resolve this trade-off, we developed the THINC/Advanced WLIC (THINC/AWLIC) method, which introduces a new weighting function.
In the proposed method, by continuously controlling the contributions of the first-order upwind scheme and the THINC scheme based on the interface normal direction, we achieve accurate transport of the interface shape while suppressing unnecessary numerical diffusion. In particular, we confirmed that by appropriately setting the control parameters, the sharpness of the interface was significantly improved compared to the conventional THINC/WLIC method, and geometric accuracy was also maintained.
Verification on 2D and 3D benchmark problems and complex flow fields showed that the proposed method showed superior interface capture performance compared to conventional methods, and showed that accuracy comparable to the PLIC method can be achieved with a much simpler implementation. Furthermore, we have confirmed its effectiveness when applied to actual multiphase flow simulations.
This research provides a fundamental technology that accelerates the application of CFD to large-scale engineering systems by realizing a highly accurate and easy-to-implement interface capture scheme.
Conceptual diagram of interface capture in THINC/AWLIC method
reference:T. Fukuda et al. (2025) Development of a new THINC/WLIC method based on a separate evaluation of the geometrical fidelity and the interface sharpness, Journal of Computational Physics