A new multi-component diffuse interface model with the Peng-Robinson equation of state is developed. Initial values of mixtures are given through the NVT flash calculation. This model is physically consistent with constant diffusion parameters, which allows us to use fast solvers in the numerical simulation. In this paper, we employ the scalar auxiliary variable (SAV) approach to design numerical schemes. It reformulates the proposed model into a decoupled linear system with constant coefficients that can be solved fast by using fast Fourier transform. Energy stability is obtained in the sense that the modified discrete energy is non-increasing in time. The calculated interface tension agrees well with laboratory experimental data.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): BAS/1/1351-01
Acknowledgements: Z. Qiao’s work is partially supported by Hong Kong Research Council GRF grant No. 15325816. S. Sun and T. Zhang gratefully acknowledge that the research reported in this publication was supported by King Abdullah University of Science and Technology (KAUST) through the grant BAS/1/1351-01 and National Nature Science Foundation of China (No. 51874262).