(6bd) Multiphase Flow Research for Sustainable Production and Use of Energy, Chemicals and Water

<align="center" style="text-align: left;">4th Year Postdoctoral Fellow

Research Interests:

My research interests span the broad areas of experimental and computational fluid dynamics and its applications, with a focus on multiphase flow reactor systems. My current research mainly focuses on developing advanced models for polydisperse multiphase flow and multiphase turbulence.  I firmly believe that a judicious balance of theory, experiments and computation can yield critical insight into multiphase flow physics that enables the development of physics-based models that can be predictive and robust, which in turn can lead to more efficient and sustainable production and use of energy, chemical and water, thus generate broad impact to industries and society.  Looking forward, I am expecting to apply my research experience and talent to advance both fundamental research and applications of multiphase flow science.

Postdoctoral Project: 

1. “A novel Taylor-Couette photobioreactor for energy efficient micro-algae cultivation.” –Conoco-Phillips

Under supervision of R. Dennis Vigil and Jacqueline V. Shanks, Department of Chemical and Biological Engineering, Iowa State University

     2.  “Kinetic Theory Modeling of Turbulent Multiphase Flow”—DOE-NETL

     3.  “Development of a computational fluid dynamic model for large-scale three-phase stirred-tank reactor.” —SABIC

Under supervision of Rodney O. Fox, Department of Chemical and Biological Engineering, Iowa State University

PhD Dissertation: 

“Experimental and computational study of turbulent mixing in a confined rectangular reactor.”

Under supervision of Michael G. Olsen and James C. Hill, Department of Mechanical Engineering, Iowa State University

Research Experience:

My academic career path has been a blend of many fields of science and engineering. I am an experimentalist by training. During my Ph.D. years at Iowa State, I performed PIV, LDV, PLIF and reactive PLIF measurements to study turbulent mixing and reacting flows, and accumulated extensive experience on various laser-based fluid diagnostic techniques.  After I earned my Ph.D., I worked with Dr. Dennis Vigil and Dr. Jacqueline Shanks as a post-doctoral research associate to develop a novel Taylor-Couette photobioreactor for energy efficient micro-algae cultivation. I also successfully developed a multi-dimensional numerical method for simulating the spectral light distribution in algal photobioreactors based on the characteristics of algae cells, which attracted wide interest from algae bio-refinery community. Furthermore, I designed and conducted various experimental and computational studies on the gas-liquid hydrodynamics and mass transfer in algal bioreactors. Since then, I worked under Dr. Rodney Fox to develop an advanced polydispersed multiphase model based quadrature-based moment method (QBMM) for energy applications, such as bio-mass gasification, which is a project funded by DOE. The model was successfully developed and implemented in both OpenFOAM and MFIX, and validated with Euler-Lagrange simulations. Currently, I am working on advanced gas-solid multiphase turbulence models, which is not well understood or predicted in spite of their critical importance to engineering design and energy policy.  What is more, in the last two years, I worked on three industrial projects sponsored by major petrochemical companies, BP, SABIC, and Chevron-Phillips, which helped me accumulate some good experiences in working with industries using open-sourced CFD software. In summary, my background in fundamental research in multiphase flow science, code development, high performance simulation, industrial applications, and experimental studies of fluid systems brought me extraordinary broad and deep knowledge and skills to allow me work closely with people with different background to solve some important and complicated issues of industries and society today.

Teaching Experience:

Aside from my research career, I also have extensive teaching experience.  I TAed and guest-lectured undergraduate lecture and laboratory courses in both Mechanical and Chemical Engineering at the Iowa State University; I was repeatedly chosen by my department to be the “Fluent Expert” (duties included lecture undergrads, holding office hours and developing course material); and, lastly, I mentored many graduate students in my group.

Future Direction: 

As faculty I would like to continue applying my extensive background experimental and computational fluid dynamics to achieve higher efficiency and sustainability in producing and use of energy, chemicals and water.  In particular, there are three areas I am very interested to work on. First, with my experiences on bioreactor design and optimization, I would like to conduct more research on using microalgae to treat wastewater and produce high value chemicals. For example, the wastewater from crude oil desalting process is high in inorganic salts, which can’t be removed by using traditional bio-degenerate method, but it can be used to culture high pH and high salt tolerated microalgae or cyanobacteria, such as Dunaliella and Euhalothece spp. Second, I want to develop a better model for gas liquid mass transfer based on a deeper understanding of this phenomenon. The hybrid model between penetration theory and eddy-cell model we developed is quite ad-hoc, which performs well in weak and highly turbulent flow regimes, but not in the moderately turbulent flow conditions. But in real industrial reactors, the flow conditions are always complex, ranging from laminar to highly turbulent, which we didn't find any published models so far can handle. Thus, I would like to propose a well-thought experiment study to collect information on this issue, gain better fundamental understanding on it, and develop a more accurate and more general gas-liquid mass transfer model. Third, I would like to explore the application of QBMM method to the area of atomization and sprays. Either volume of fluid (VOF) or level-set method can be used to simulate the fuel droplet formation near the nozzle, or then the results can be fed into a variable droplet size model with size-conditioned velocity to model the flow development and combustion further downstream. Overall, I am looking forward to get an opportunity to conduct more interesting researches which can contribute more of my effort to the society.

Selected Publications:

M. Ramezania, B. Kong, X. Gao, M. G. Olsen and R. D. Vigil, ``Experimental measurement of oxygen mass transfer and bubble size distribution in an air-water multiphase Taylor-Couette vortex bioreactor", Chemical Engineering Journal 270 (2015): 508-518.

X. Gao, B. Kong and R. D. Vigil, ``CFD investigation of bubble effects on Taylor-Couette flow patterns in the weakly turbulent vortex regime", Chemical Engineering Journal, vol. 270 pp. 508-518, 2015.

C. Yuan, B. Kong, A. Passalacqua, and R. O. Fox, ``An extended quadrature-based mass-velocity moment model for polydisperse bubbly flows", The Canadian Journal of Chemical Engineering, vol. 92, no. 12, pp. 2053-2066, 2014.

K. M. Nilsen, B. Kong, R. O. Fox, J. C. Hill, and M. G. Olsen, ``Effect of inlet conditions on the accuracy of large eddy simulations of a turbulent rectangular wake", Chemical Engineering Journal, vol. 250, pp. 175-189, Aug. 2014.

B. Kong and R. D. Vigil, ``Simulation of photosynthetically active radiation distribution in algal photobioreactors using a multidimensional spectral radiation model", Bioresource Technology, vol. 158, pp. 141-148, Apr. 2014.

B. Kong and R. D. Vigil, ``Light-limited continuous culture of Chlorella vulgaris in a Taylor vortex reactor", Environ. Prog. Sustainable Energy, vol. 32, no. 4, pp. 884-890, Dec. 2013.

B. Kong, J. V. Shanks, and R. D. Vigil, ``Enhanced algal growth rate in a Taylor vortex reactor", Biotechnology and Bioengineering. vol. 110, no. 8, pp. 2140–2149, Aug. 2013.

B. Kong, M. G. Olsen, R. O. Fox, and J. C. Hill, ``Predictive capability of Large Eddy Simulation for point-wise and spatial turbulence statistics in a confined rectangular jet", Chemical Engineering Science, vol. 69, no. 1, pp. 240-256, Feb. 2012.

B. Kong, M. G. Olsen, R. O. Fox, and J. C. Hill, ``Population, characteristics and kinematics of vortices in a confined rectangular jet with a co-flow", Exp Fluids, vol. 50, no. 6, pp. 1473-1493, Jun. 2011.