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Doctoral defence of Muhammad Ziaul Arif, MSc, 24.5.2024: Dual-modal electromagnetic tomography for two-phase flows

The doctoral dissertation in the field of Applied Physics will be examined at the Faculty of Science, Forestry and Technology, Kuopio Campus.

What is the topic of your doctoral research? Why is it important to study the topic?

My doctoral research focuses on "Dual-modal Electromagnetic Tomography for Two-Phase Flows." This work involves the development and application of dual-modal; Electrical Tomography (ET) and Electromagnetic Flow Tomography (EMFT) to accurately measure and analyze the critical parameters of stationary and non-stationary oil-water two-phase flows, such as velocity fields, phase fraction distribution, and phase volumetric flow rates, within industrial pipelines.

Studying this topic is crucial because two-phase flows are integral to various industrial processes, including oil and gas production, chemical manufacturing, and water treatment, etc. Precise measurement of the two-phase flow parameters is vital for optimizing these processes, enhancing production efficiency, reducing costs, and minimizing environmental impact. The dual-modal tomography approach offers a significant advancement in accurately monitoring and controlling these complex flow systems, contributing to safer and more efficient industrial operations.

What are the key findings or observations of your doctoral research?

My research has successfully demonstrated that dual-modal electromagnetic tomography can effectively reconstruct two-phase flow parameters such as velocity fields and phase fraction distributions, as well as estimating phase volumetric flow rates. The key findings include the enhanced accuracy of flow parameter estimations when combining Electrical Tomography (ET) and Electromagnetic Flow Tomography (EMFT) compared to traditional single-modality approaches. The Bayesian state-estimation approach overcomes the stationary approach. The proposed approach allows for a more detailed and accurate dynamic analysis of fluid flow parameters in pipelines.

The novelty of my research lies in the joint reconstruction approach of ET and EMFT within a Bayesian state-estimation framework to provide more robust and accurate estimating parameters of two-phase flows. The ability to accurately predict parameters changes in flow characteristics leads to better operational decisions, enhanced safety, and optimized resource management. For the scientific community, this research contributes to accurate estimating and the understanding of complex flow dynamics, offering a new tool for exploring and managing the challenges associated with multiphase flow processes. These insights have broad implications, potentially impacting fields ranging from petroleum engineering to environmental management.

How can the results of your doctoral research be utilised in practice?

The results of my doctoral research can be potentially utilized in various industrial settings where precise monitoring and control of two-phase flows are crucial, such as in oil and gas, chemical processing, and water treatment industries. The integration of Electrical Tomography (ET) and Electromagnetic Flow Tomography (EMFT) within a Bayesian framework enhances the accuracy and reliability of measuring complex flow dynamics. This improved measurement capability is vital for optimizing process efficiency, enhancing safety by anticipating and preventing hazardous conditions, and reducing operational costs through more efficient energy use and reduced maintenance.

Additionally, accurate flow measurements can aid in environmental monitoring to ensure compliance with regulatory standards. The methodologies and technologies developed also offer valuable tools for further research in fluid dynamics and can be adapted to study similar systems in other research fields, thus broadening the impact of this work across scientific and industrial communities.

What are the key research methods and materials used in your doctoral research?

My doctoral research primarily utilized dual-modal electromagnetic tomography, which combines Electrical Tomography (ET) and Electromagnetic Flow Tomography (EMFT) to investigate two-phase flows. The key methodology involved the development and application of a joint reconstruction approach within a Bayesian state estimation framework. This approach allowed for the simultaneous estimation of phase fraction distributions and velocity fields, which are critical parameters in understanding and controlling two-phase flows.

To implement this, I conducted both numerical simulations and experimental validations. Two-phase flow simulations were generated using Comsol Multiphysics software. The simulations provided a controlled environment to test and refine the tomography techniques and algorithms before applying them in real-world conditions. The experiments were carried out using complex setups in the Electrical Tomography Laboratory at Department of Technical Physics, where actual two-phase flows (oil and water) were generated and measured using the ET and EMFT systems. This dual-modal approach ensured comprehensive data collection, crucial for the accuracy of the flow measurements.

The research process involved iterative cycles of hypothesis formulation, numerical simulations, experimental design, data collection, data analysis, and validation. This systematic approach helped in fine-tuning the methodologies to address specific challenges associated with two-phase flow measurements, such as the synchronization of modalities and the handling of noisy. The use of computational tools/software for data processing and image reconstruction was also a significant aspect of the research, enabling the detailed analysis and interpretation of the complex data sets generated during experiments.

Is there something else about your doctoral dissertation you would like to share in the press release?

This research was conducted at the Department of Technical Physics, Faculty of Science, Forestry and Technology, the University of Eastern Finland, Kuopio. The financial support that facilitated this study came from the Islamic Development Bank (IsDB) Project of the University of Jember, Indonesia, alongside generous funding from The Academy of Finland (Finnish Centre of Excellence in Inverse Modelling and Imaging).

The doctoral dissertation of Muhammad Ziaul Arif, MSc, entitled Dual-modal electromagnetic tomography for two-phase flows will be examined at the Faculty of Science, Forestry and Technology, Kuopio Campus. The opponent will be Professor Manuchehr Soleimani, University of Bath, UK, and the custos will be Professor Marko Vauhkonen, University of Eastern Finland. Language of the public defence is English.

For more information, please contact: 

Muhammad Ziaul Arif, muhammad.arif@uef.fi, tel. +358 449 109 836