Education

Research Description

Dr. Bolotnov is interested in using multiscale approaches for nuclear reactor simulations, development of new spectral cascade transfer multiphase flow turbulence models, and direct numerical simulation of single and multiphase turbulent flows.

Publications

A Perspective on Data-Driven Coarse Grid Modeling for System Level Thermal Hydraulics

Iskhakov, A. S., Tai, C.-K., Bolotnov, I. A., & Dinh, N. T. (2022, September 10), NUCLEAR SCIENCE AND ENGINEERING, Vol. 9. https://doi.org/10.1080/00295639.2022.2107864

An adaptive knowledge-based data-driven approach for turbulence modeling using ensemble learning technique under complex flow configuration: 3D PWR sub-channel with DNS data

Zhu, Y., Dinh, N. T., Saini, N., & Bolotnov, I. A. (2022), NUCLEAR ENGINEERING AND DESIGN, 7. https://doi.org/10.1016/j.nucengdes.2022.111814

Direct Numerical Simulation of Bubble Formation Through a Submerged "Flute" With Experimental Validation

Pillai, N., Sponsel, N. L., Stapelmann, K., & Bolotnov, I. A. (2022), JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME, 2. https://doi.org/10.1115/1.4052051

Selected papers from the 2020 International Topical Meeting on Advances in Thermal Hydraulics (ATH'20) Foreword

Bolotnov, I., & Benhamadouche, S. (2022, August 3), NUCLEAR TECHNOLOGY, Vol. 8. https://doi.org/10.1080/00295450.2022.2086385

Detailed Analysis of the Effects of Spacer Grid and Mixing Vanes on Turbulence in a PWR Subchannel Under DFFB Conditions Based on DNS Data

Saini, N., & Bolotnov, I. A. (2021, December 8), NUCLEAR TECHNOLOGY, Vol. 12. https://doi.org/10.1080/00295450.2021.1974279

Evaluation of Length Scales and Meshing Requirements for Resolving Two-Phase Flow Regime Transitions Using the Level Set Method

Zimmer, M. D., & Bolotnov, I. A. (2021), JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME, 143(6). https://doi.org/10.1115/1.4049934

Progress in multiphase computational fluid dynamics

Lahey, R. T., Jr., Baglietto, E., & Bolotnov, I. A. (2021), NUCLEAR ENGINEERING AND DESIGN, 374. https://doi.org/10.1016/j.nucengdes.2020.111018

Two-Phase Turbulence Statistics from High Fidelity Dispersed Droplet Flow Simulations in a Pressurized Water Reactor (PWR) Sub-Channel with Mixing Vanes

Saini, N., & Bolotnov, I. A. (2021), FLUIDS, 6(2). https://doi.org/10.3390/fluids6020072

Annular Flow Simulation Supported by Iterative In-Memory Mesh Adaptation

Fang, J., Purser, M. K., Smith, C., Balakrishnan, R., Bolotnov, I. A., & Jansen, K. E. (2020), NUCLEAR SCIENCE AND ENGINEERING. https://doi.org/10.1080/00295639.2020.1743577

Exploring Two-Phase Flow Regime Transition Mechanisms Using High-Resolution Virtual Experiments

Zimmer, M. D., & Bolotnov, I. A. (2020), NUCLEAR SCIENCE AND ENGINEERING. https://doi.org/10.1080/00295639.2020.1722543

View all publications via NC State Libraries

Grants

Biocatalyst Interactions with Gases (BIG) Collaboration

Novo Nordisk Foundation(9/01/22 - 8/31/27)

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Biocatalyst Interactions with Gases (BIG) Collaboration

Sponsor: Novo Nordisk Foundation

Start Date: 9/01/22

End Date: 8/31/27

Abstract

This fundamental research is motivated by three major global challenges that directly involve the transformation of gas molecules: carbon dioxide (CO2) capture for greenhouse gas mitigation, CO2 conversion to fuels and chemicals, and nitrogen (N2) gas conversion to biologically available ammonia to meet growing fertilizer demand. The research focuses on creating and investigating multi-functional interfaces that durably immobilize enzymes near their gaseous substrates while simultaneously delivering essential chemical and electrical reducing equivalents and removing reaction products to achieve maximum catalytic rates. Biocatalytic systems to be explored are: conversion of CO2 to bicarbonate catalyzed by carbonic anhydrase, reduction of CO2 to formate catalyzed by formate dehydrogenase, and reduction of N2 to ammonia catalyzed by nitrogenase. We envision that minimization of reaction barriers near immobilized biocatalyst interfaces involving gas molecule conversions will lead to transformative innovations that help overcome global sustainability challenges.

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High-performance computing studies of HFIR flow channel

Oak Ridge National Laboratories - UT-Battelle LLC(8/26/21 - 3/31/22)

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High-performance computing studies of HFIR flow channel

Sponsor: Oak Ridge National Laboratories - UT-Battelle LLC

Start Date: 8/26/21

End Date: 3/31/22

Abstract

High resolution computational fluid dynamics simulations of the HFIR reactor channel will be designed. Those simulations will demonstrate the practicality of the DNS or LES approach to understand the flow phenomenon of complex geometries of interest.

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Two-Phase Flow DNS Phase 2 Project

Mitsubishi Heavy Industries, Ltd.(5/01/21 - 10/31/22)

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Two-Phase Flow DNS Phase 2 Project

Sponsor: Mitsubishi Heavy Industries, Ltd.

Start Date: 5/01/21

End Date: 10/31/22

Abstract

The project will apply state-of-the-art two-phase flow DNS techniques for advanced heat exchanger designs. New capabilities will be added as necessary, and advanced analysis techniques will be applied to support coarse-grid model development.

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Plasma Breakdown and Instabilities in the Multiphase Plasma-Gas Bubble-Liquid System

National Science Foundation (NSF)(5/01/21 - 4/30/24)

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Plasma Breakdown and Instabilities in the Multiphase Plasma-Gas Bubble-Liquid System

Sponsor: National Science Foundation (NSF)

Start Date: 5/01/21

End Date: 4/30/24

Abstract

The goal of this research program is to gain fundamental understanding of the multi-phase plasma-gas-liquid system by utilizing both theoretical and experimental approaches. The plasma breakdown and streamer development in steep gradients will be investigated dependent on realistic bubble geometries and as a function of applied voltage conditions. The multiphase interface tracking DNS code PHASTA has been well-established through a wide variety of two-phase flow problems. When coupled with the well-established plasma modeling and characterization code nonPDPSIM, it will give new insights into gas bubble formation and how the size and shape of the bubbles will influence the breakdown of the plasma. The experiment will allow the production of various well-defined bubble shapes and sizes, making it possible to investigate the dependency of the plasma breakdown on bubble geometries. The project will provide 1) the initial steps to combine high-resolution multiphase physics with electric fields and plasma physics, opening the opportunity to study fundamental plasma physics in a multiphase system, and 2) the experimental investigations to benchmark the simulations and to study how the polarity of the applied voltage pulses affects the streamer propagation in a bubble in liquids.

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Multiple Bubble Boiling Simulation Scaling and Evaluation

US Dept. of Energy (DOE)(9/08/20 - 11/30/20)

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Multiple Bubble Boiling Simulation Scaling and Evaluation

Sponsor: US Dept. of Energy (DOE)

Start Date: 9/08/20

End Date: 11/30/20

Abstract

The proposed high resolution simulation efforts will evaluate the boiling capabilities in different pressure conditions and compare the results with existing models, experiments and previously published simulations. The work will evaluate the interface capturing approach capabilities for the problems of interest and will provide the recommendations about requirements and future research to expand those capabilities.

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Center for thermal-fluids application in nuclear energy: Establishing the knowledge base for thermal-hydraulic multiscale simulation to accelerate the deployment of advanced reactors.

US Dept. of Energy (DOE)(10/01/20 - 9/30/23)

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Center for thermal-fluids application in nuclear energy: Establishing the knowledge base for thermal-hydraulic multiscale simulation to accelerate the deployment of advanced reactors.

Sponsor: US Dept. of Energy (DOE)

Start Date: 10/01/20

End Date: 9/30/23

Abstract

In this DOE-funded project the NCSU team will support the larger effort in establishing the knowledgebase for thermal-hydraulic multiscale simulation to accelerate the deployment of advanced reactors. NCSU focus will be on performing high resolution simulations of advanced reactor flows as well as developing advanced methodologies for data processing using machine-learning techniques.

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Pilot Study on Two-Phase flow DNS Application to Heat Transfer Enhancement Pipe

Mitsubishi Heavy Industries, Ltd.(7/01/20 - 12/31/20)

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Pilot Study on Two-Phase flow DNS Application to Heat Transfer Enhancement Pipe

Sponsor: Mitsubishi Heavy Industries, Ltd.

Start Date: 7/01/20

End Date: 12/31/20

Abstract

Finite-element based flow solver (PHASTA) [1] [2] [3] with Level-Set method for interface tracking is proposed to perform bubble/flow interaction studies. This code has been successfully applied to large scale direct numerical simulation (DNS) of turbulent flows in various geometries, as well as interface tracking simulations (including bubbly channel flow [4] [5], annular flow [6], reactor geometry flows [7], Fig. 1). Flexible data analysis tools have been developed to quantify turbulence parameters [8] [9], including spectral information [10] and will be further improved to satisfy the needs of the proposed study. This set of tools was recently used by the PI-Bolotnov to quantify the influence of bubbles on the turbulence anisotropy in a channel [11]. It has been demonstrated that the controlled-bubble approach is validated [12], drag and lift force can be evaluated [13], bubble-induced turbulence can be evaluated [14] and the wall-effects on the interfacial forces can be studied [15].

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Computationally Efficient Prediction of Containment Thermal Hydraulics Using Multi-Scale Simulation

US Dept. of Energy (DOE)(11/21/16 - 9/30/18)

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Computationally Efficient Prediction of Containment Thermal Hydraulics Using Multi-Scale Simulation

Sponsor: US Dept. of Energy (DOE)

Start Date: 11/21/16

End Date: 9/30/18

Abstract

Analysis of containment phenomena requires addressing three-dimensional (3D) phenomena over large length scales, making existing high-quality Computational Fluid dynamics (CFD) techniques infeasible. The project objective is to develop a coarse-grained (CG) CFD capability to make sufficiently high-fidelity analysis of containment thermal-hydraulics feasible. The project will evaluate feasibility of a data-driven multi-scale framework to enable computationally efficient simulation of containment thermal-hydraulic processes. Through two case studies, the project will investigate (1) applicability of scale separation and mixing length hypotheses, (2) the effect of mesh size on solution, (3) error recovery through data-driven sub-grid-scale (SGS) models, (4) identifiability and dimensionless characterization of 3D flow patterns, and (5) Bayesian calibration of a SGS model on high-fidelity flow field data. Based on insights gained, the project will formulate a framework for data-driven multiscale simulation, recommendations for high-fidelity CFD data archiving, classification, mining, and assimilation, and requirements for construction of surrogate SGS models

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Research and Technical Assistance Related to Severe Accidents in Nuclear Power Plants

US Nuclear Regulatory Commission(9/08/16 - 6/30/19)

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Research and Technical Assistance Related to Severe Accidents in Nuclear Power Plants

Sponsor: US Nuclear Regulatory Commission

Start Date: 9/08/16

End Date: 6/30/19

Abstract

A team of researchers led by the University of Wisconsin-Madison (UW), and comprising Texas A&M University (TAMU), California Institute of Technology (CalTech), and North Carolina State University (NCSU) is proposing to establish a university-based center focused on severe accident research and technical assistance. Our team’s research objectives are to: (i) conduct research in severe accident phenomena, in particular, those phenomena where residual uncertainties remain in light of Fukushima, and reduction of such uncertainties is warranted to address high priority Near-Term Task Force (NTTF) recommendations; (ii) provide technical assistance to the NRC related to post Fukushima safety and severe accident research; and (3) develop and maintain a repository of knowledge in severe accident research. Specific areas of technical assistance in which the center has substantial expertise and experience include in-vessel core heatup and core degradation phenomena; ex-vessel phenomena, including fuel-coolant interactions and core-concrete interactions; hydrogen mixing, combustion and control strategies; reactor system behavior under beyond-design basis conditions, and advanced modeling techniques, including reactor systems modeling and Computational Fluid Dynamics (CFD) methods that can be used in severe accident evaluation.

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Computationally Efficient Prediction of Containment Thermal Hydraulics Using Multi-Scale Simulation: Feasibility Study (FY 16 NUC)

US Dept. of Energy (DOE)(12/23/15 - 9/30/16)

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Computationally Efficient Prediction of Containment Thermal Hydraulics Using Multi-Scale Simulation: Feasibility Study (FY 16 NUC)

Sponsor: US Dept. of Energy (DOE)

Start Date: 12/23/15

End Date: 9/30/16

Abstract

The project technical objective is to develop and evaluate feasibility of a technical basis for the coarse-grained (CG) CFD capability that is needed for high-fidelity analysis of containment thermal-hydraulics. Specifically, the project will investigate a data-driven multi-scale framework having the potential to enable computationally efficient simulation of containment thermal-hydraulic processes.

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