基于边界元方法的两相层状流相界面重建

BEM Based Algorithm to Reconstruct Phase Interface in Stratified Two-Phase Flow

两相层状流广泛存在于工业生产过程中,对于其相界面的准确测量对于保障生产安全,提高生产效率具有重要的意义。电容层析成像技术是一种非接触的过程可视化技术,非常适合多相流测量.但是由于其逆问题的非线性和病态性,其测量精度不高.为了解决这一问题,一种新型的两相流层状界面重建方法被提出,用于直接反演计算出管道内部层状界面的几何形状.区别于以往基于区域剖分的重建算法,测量数据与被测形状之间的映射关系通过一组边界积分方程直接的被建立出来,然后通过非线性迭代的方法逼近被测界面的几何形状。仿真实验表明,该形状重建算法具有高的精度和收敛速度,而且具有很好的抗噪能力.

Two-phase flows widely exist in many industries. Measuring the interfaces between different phases is important for the optimization and control of some industrial processes. ECT is a non-invasive process visualization method and very suitable for the measurement of multiphase flow. However, due to the ill-posed and ill-condition character of its inverse problem, its spatial resolution is low. This paper proposed an ECT reconstruction algorithm for measuring the phase interface in stratified two-phase flow. This method can directly estimate the geometric shape of layered interfaces inside the pipeline. Different from the pixel based reconstruction algorithms, BEM is adopted to build the forward mapping from the interracial shape to the boundary data, and then search the optimal shape estimation using some nonlinear iteration method. After several numerical experiments, this approach is proved fast and precise.