The ubiquity of two-phase systems has rendered them a subject of prime importance especially from numerical perspectives. Among several methods described in the literature, which are generally classified as sharp or diffuse interface methods, phase-field (diffuse interface) method has been at the paramount of several recent investigations owing to its several advantages, primarily to handle complex topological changes. Though several advancements have been made in the subject, one of the important challenges with this approach using Cahn-Hilliard equation lies in the determination of an appropriate value of mobility. Despite certain propositions in the literature in terms of non-dimensional numbers (Peclet and Cahn numbers), ambiguity in the velocity scale to be chosen for evaluating mobility poses a challenge for their straightforward extension to real systems. In addition it renders the system to be dependent on numerical parameters. In the current work, we address this problem using a new approach to calculate the mobility parameter in terms of local equilibrium interface thickness which in itself is evaluated from the phase-field parameter. Consequently, this helps to make the model independent of numerical parameters making it more reliable. We test this approach for several canonical and complex cases, such as the rise of lighter bubble in a heavier medium, bubble coalescence, Rayleigh-Taylor instability. The results are compared with those in literature or obtained using level set method. An excellent agreement is observed illustrating the potential of this approach to make phase-field model more prominent.

两相系统的普遍性使它们成为最重要的主题，尤其是从数值角度来看。在文献中描述的几种方法中，通常被归类为锐利或漫反射界面方法，相场（漫反射界面）方法由于其几个优点，主要用于处理复杂的拓扑变化，因此在最近的几项研究中处于最重要的位置。尽管该主题取得了一些进展，但使用 Cahn-Hilliard 方程的这种方法的重要挑战之一在于确定适当的流动性值。尽管文献中有一些关于无量纲数（佩克莱特数和卡恩数）的命题，用于评估移动性的速度尺度的模糊性对其直接扩展到实际系统提出了挑战。此外，它使系统依赖于数值参数。在当前的工作中，我们使用一种新方法来解决这个问题，该方法根据局部平衡界面厚度计算迁移率参数，该厚度本身是从相场参数评估的。因此，这有助于使模型独立于数值参数，使其更加可靠。我们在几种典型和复杂的情况下测试了这种方法，例如较重介质中较轻气泡的上升、气泡合并、瑞利-泰勒不稳定性。将结果与文献中的结果进行比较或使用水平集方法获得。