Flow regime classification using various dimensionality reduction methods and AutoML

• Published in: Engineering analysis with boundary elements 2024-06, Vol.163, p.161-174
• Main Authors: Khan, Umair, Pao, William, Pilario, Karl Ezra, Sallih, Nabihah
• Format: Article
• Language: English
• Subjects: Automated machine learning; Dimensionality reduction; Discreate wavelet transform; Dynamic pressure; Two-phase flow; Virtual flow regime map
• ISSN: 0955-7997; 1873-197X
• DOI: 10.1016/j.enganabound.2024.03.006

•Two-phase flow regime identification using ML with enhanced interpretability.•Evaluation of various dimensionality reduction techniques to optimize feature representation.•Kernel Fisher discriminant analysis is the best performing dimensionality reduction technique.•AutoML can impartially select the most effective ML classifier.•Our workflow can develop a virtual flow regime map to automate flow regime recognition. Accurate identification of flow regimes is paramount in several industries, especially in chemical and hydrocarbon sectors. This paper describes a comprehensive data-driven workflow for flow regime identification. The workflow encompasses: i) the collection of dynamic pressure signals using an experimentally verified numerical two-phase flow model for three different flow regimes: stratified, slug and annular flow, ii) feature extraction from pressure signals using Discrete Wavelet Transformation (DWT), iii) Evaluation and testing of 12 different Dimensionality Reduction (DR) techniques, iv) the application of an AutoML framework for automated Machine Learning classifier selection among K-Nearest Neighbors, Artificial Neural Networks, Support Vector Machines, Gradient Boosting, Random Forest, and Logistic Regression, with hyper-parameter tuning. Kernel Fisher Discriminant Analysis (KFDA) is the best DR technique, exhibiting superior goodness of clustering, while KNN proved to be the top classifier with an accuracy of 92.5 % and excellent repeatability. The combination of DWT, KFDA and KNN was used to produce a virtual flow regime map. The proposed workflow represents a significant step forward in automating flow regime identification and enhancing the interpretability of ML classifiers, allowing its application to opaque pipes fitted with pressure sensors for achieving flow assurance and automatic monitoring of two-phase flow in various process industries.