Considering the complex physical and chemical process of gas-surface interactions in hypersonic flows, we conducted researches starting from microscopic molecular dynamics (MD), developed mesoscopic gas-solid interaction models, and then deduced macroscopic slip boundary conditions with the help of molecular kinetic theory [7-9], as shown in Fig. 3. For dynamic wetting involving three phase moving contact line, we developed multiscale modelling method by coupling CFD and MD simulations [10, 11], as shown in Fig. 4.

Fig. 3. Multiscale simulation of GSI for hypersonic flows.

Fig. 4. Multiscale simulation of dynamic wetting.

[7] P. Luan, H. Yang, Q. Ma, and J. Zhang*, "A theoretical derivation of slip boundary conditions based on the Cercignani–Lampis–Lord scattering model," Journal of Fluid Mechanics 999, A36 (2024).

[8] J. Zhang*, P. Luan, J. Deng, P. Tian, and T. Liang, "Theoretical derivation of slip boundary conditions for single-species gas and binary gas mixture," Physical Review E 104, 055103 (2021).

[9] J. Deng, J. Zhang*, T. Liang, J. Zhao, Z. Li, and D. Wen, "A modified Cercignani–Lampis model with independent momentum and thermal accommodation coefficients for gas molecules scattering on surfaces," Physics of Fluids 34, 107108 (2022).

[10] J. Zhang*, M. K. Borg, and J. M. Reese, "Multiscale simulation of dynamic wetting," International Journal of Heat and Mass Transfer 115, 886 (2017).

[11] H. Liu, J. Zhang*, P. Capobianchi, M. K. Borg, Y. Zhang, and D. Wen, "A multiscale volume of fluid method with self-consistent boundary conditions derived from molecular dynamics," Physics of Fluids 33, 062004 (2021).