一种新的时间步长准则用于不可混溶双相流的IMPES求解器模拟
A new Timestep Criterion for the Simulation of Immiscible Two-Phase Flow with IMPES Solvers
AI总结：
本文提出了一种迭代IMPES求解器和新的时间步长准则，用于模拟涉及压缩性流体相的不可混溶双相流。该时间步长准则结合Courant-Friedrichs-Lewy条件和数值计算的速度导数，适应时间步长大小，不依赖主导流动特征。该求解器在多种流动场景中表现出高效和鲁棒性，包括压降主导和毛细管主导流动，且无需调整任何数值参数。此外，它在具有不连续多孔介质参数（如孔隙率、渗透率和毛细管压力函数）的案例中成功达到预期的稳态状态。与传统Coats时间步长准则相比，本文的方法在Buckley-Leverett问题和重力-毛细管平衡示例中保持了相似的精度，但时间迭代次数更少。在空气压缩示例中，新时间步长准则在非润湿相质量守恒方面显著优于Coats准则。
摘要：
我们提出了一种迭代IMPES求解器和一种新的时间步长准则，用于模拟涉及压缩性流体相的不可混溶双相流。新的时间步长准则利用Courant-Friedrichs-Lewy（CFL）条件，并利用数值计算的速度导数来适应时间步长大小，而不依赖于主导流动特征。该求解器结合该时间步长准则在多种流动场景中表现出高效和鲁棒性，包括压降主导和毛细管主导流动，无论流体相是压缩还是不可压缩。此外，它在具有不连续多孔介质参数（如孔隙率、渗透率和毛细管压力函数）的案例中成功达到预期的稳态状态。与传统Coats时间步长准则的比较表明，本文的方法在Buckley-Leverett问题和具有已知稳态状态的重力-毛细管平衡示例中保持了相似的精度，但时间迭代次数更少。此外，在空气压缩示例中，新时间步长准则在非润湿相质量守恒方面显著优于Coats准则。
英文摘要：
We present an iterative IMPES solver and a novel timestep criterion for the simulation of immiscible two-phase flow involving compressible fluid phases. The novel timestep criterion uses the Courant-Friedrichs-Lewy (CFL) condition and employs numerically computed velocity derivatives to adapt the timestep size, regardless of the dominant flow characteristics. The solver combined with this timestep criterion demonstrates both efficiency and robustness across a range of flow scenarios, including pressure drop dominated and capillary dominated flows with compressible and incompressible fluid phases, without the need to adjust any numerical parameters. Furthermore, it successfully reaches the expected stationary states in a case involving discontinuous porous media parameters such as porosity, permeabilities, and capillary pressure function. Comparison with the established Coats timestep criterion reveals that our approach requires fewer time iterations while maintaining comparable accuracy on the Buckley-Leverett problem and a gravity-capillary equalization example with a known stationary state. Additionally, in an example with air compression, the new timestep criterion leads to a significantly improved non-wetting phase mass conservation compared to the Coats criterion.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
