Education

Research Description

The Multiphase Research Group focuses on 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

High-Fidelity Simulation of the Light-to-Dense Stratification Transient in the HiRJET Facility

Tai, C.-K., Yuan, H., Merzari, E., & Bolotnov, I. A. (2024, August 23), NUCLEAR TECHNOLOGY, Vol. 8. https://doi.org/10.1080/00295450.2024.2382621

NEAMS IRP challenge problem 1: Flexible modeling for heat transfer for low-to-high Prandtl number fluids for applications in advanced reactors

Bolotnov, I. A., Iskhakov, A. S., Nguyen, T., Tai, C.-K., Wiser, R., Baglietto, E., … Merzari, E. (2024), NUCLEAR ENGINEERING AND DESIGN, 428. https://doi.org/10.1016/j.nucengdes.2024.113467

A direct numerical simulation study to elucidate the enhancement of heat transfer for nucleate boiling on surfaces with micro-pillars

Zhang, J., Rafique, M., Ding, W., Bolotnov, I. A., & Hampel, U. (2023), INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, 147. https://doi.org/10.1016/j.icheatmasstransfer.2023.106943

Data-Driven RANS Turbulence Closures for Forced Convection Flow in Reactor Downcomer Geometry

Iskhakov, A. S., Tai, C.-K., Bolotnov, I. A., Nguyen, T., Merzari, E., Shaver, D. R., & Dinh, N. T. (2023, March 16), NUCLEAR TECHNOLOGY, Vol. 3. https://doi.org/10.1080/00295450.2023.2185056

Direct Numerical Simulation of Low and Unitary Prandtl Number Fluids in Reactor Downcomer Geometry

Tai, C.-K., Nguyen, T., Iskhakov, A. S., Merzari, E., Dinh, N. T., & Bolotnov, I. A. (2023, June 17), NUCLEAR TECHNOLOGY, Vol. 6. https://doi.org/10.1080/00295450.2023.2213286

Direct Numerical Simulation of Single- and Two-Phase Flows for Nuclear Engineering Geometries

Bolotnov, I. A. (2023, July 24), NUCLEAR TECHNOLOGY, Vol. 7. https://doi.org/10.1080/00295450.2023.2232222

Direct numerical simulation of heat transfer on a deformable vapor bubble rising in superheated liquid

Li, J., Liao, Y., Bolotnov, I. A., Zhou, P., Lucas, D., Li, Q., & Gong, L. (2023), PHYSICS OF FLUIDS, 35(2). https://doi.org/10.1063/5.0137675

Direct numerical simulation of microlayer formation and evaporation underneath a growing bubble driven by the local temperature gradient in nucleate boiling

Zhang, J., Rafique, M., Ding, W., Bolotnov, I. A., & Hampel, U. (2023), INTERNATIONAL JOURNAL OF THERMAL SCIENCES, 193. https://doi.org/10.1016/j.ijthermalsci.2023.108551

Interface Capturing Flow Boiling Simulations in a Compact Heat Exchanger

Iskhakova, A., Kondo, Y., Tanimoto, K., Dinh, N. T., & Bolotnov, I. A. (2023), ASME JOURNAL OF HEAT AND MASS TRANSFER, 145(4). https://doi.org/10.1115/1.4056688

Study of Stable Stratification in HiRJET Facility With Direct Numerical Simulation

Tai, C.-K., Mao, J., Petrov, V., Manera, A., & Bolotnov, I. A. (2023, June 9), NUCLEAR SCIENCE AND ENGINEERING, Vol. 6. https://doi.org/10.1080/00295639.2023.2197656

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

National Science Foundation (NSF)(5/01/21 - 4/30/25)

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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: 4/30/25

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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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 - 9/30/24)

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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: 9/30/24

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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ICS Heat Exchange Optimization, CNP Core Project 8

Consortium for Nuclear Power (CNP)- Dept of Nuclear Engineering(7/01/22 - 6/30/23)

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ICS Heat Exchange Optimization, CNP Core Project 8

Sponsor: Consortium for Nuclear Power (CNP)- Dept of Nuclear Engineering

Start Date: 7/01/22

End Date: 6/30/23

Abstract

The proposed scope will focus on demonstrating the DNS capabilities for GE���s problem of interest. Specifically, complex geometries and two-phase flow behavior at various flow conditions can be studied. The following tasks can be planned for the first year of the project: 1) Identify geometry of interest to the industry and flow conditions suitable for DNS level meshing in collaboration with the CNP member 2) Demonstrate the meshing capabilities for selected geometry 3) Perform single phase flow simulations and collect basic statistics (e.g. averaged flow profiles) 4) Demonstrate two-phase flow simulation capabilities in flow regime suitable to DNS in this geometry 5) Evaluate the traditional modeling approach knowledge gaps and demonstrate how those can be narrowed / filled using high resolution simulations 6) Demonstrate how DNS statistical analysis can support for industry scale simulations capabilities

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Two Phase Flow Modeling and Simulation ��� CNP Core Project 7

Consortium for Nuclear Power (CNP)- Dept of Nuclear Engineering(7/01/22 - 6/30/23)

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Two Phase Flow Modeling and Simulation ��� CNP Core Project 7

Sponsor: Consortium for Nuclear Power (CNP)- Dept of Nuclear Engineering

Start Date: 7/01/22

End Date: 6/30/23

Abstract

The proposed scope will focus on demonstrating the DNS capabilities for GE���s problem of interest. Specifically, complex geometries and two-phase flow behavior at various flow conditions can be studied. The following tasks can be planned for the first year of the project:

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

Mitsubishi Heavy Industries, Ltd.(10/01/22 - 5/15/23)

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

Sponsor: Mitsubishi Heavy Industries, Ltd.

Start Date: 10/01/22

End Date: 5/15/23

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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PHASTA PID CONTROLLER

US Dept. of Energy (DOE)(11/01/22 - 3/07/23)

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PHASTA PID CONTROLLER

Sponsor: US Dept. of Energy (DOE)

Start Date: 11/01/22

End Date: 3/07/23

Abstract

The PHASTA code is a two-phase direct numerical simulation code that uses the level set method for interface capturing. NNL has begun to use a version of PHASTA to explore physics fundamental to two-phase flow and generate high-fidelity numerical data to formulate multiphase computational fluid dynamics (MCFD) models. PHASTA is an open-source code that is available on GitHub. The PID controller capability will be transferred to NNL along with support as part of this project.

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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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High-Performance Computing Studies of HFIR Flow Channel

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

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High-Performance Computing Studies of HFIR Flow Channel

Sponsor: UT-Battelle, LLC dba Oak Ridge National Laboratory

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

US Nuclear Regulatory Commission(9/08/16 - 9/07/21)

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

Sponsor: US Nuclear Regulatory Commission

Start Date: 9/08/16

End Date: 9/07/21

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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