An Interview with Professor Junye Wang (Part Two)

Author(s): Scott Douglas Jacobsen

Publication (Outlet/Website): In-Sight: Independent Interview-Based Journal

Publication Date (yyyy/mm/dd): 2016/02/01

Abstract

An interview with Professor Junye Wang. He discusses: most effective means of teaching students through an online education; benefits to the professor-researcher; LinkedIn self-description and breadth of experience brought to Athabasca University; unifying theme for select research articles; Domain-decomposition method for parallel lattice Boltzmann simulation of incompressible flow in porous media (2005); pragmatic implications for implementation to research on the Athabasca River Basin; Flow simulation in a complex fluidics using three turbulence models and unstructured grids (2009); Development and application of a detailed inventory framework for estimating nitrous oxide and methane emissions from agriculture (2011); extrapolations about average annual emissions in the United Kingdom 2011 to the present and in the next decade; Theory of flow distribution in manifolds (2011); greater generality create more or less functionality; Discrete approach for flow field designs of parallel channel configurations in fuel cells (2012); and Modelling nitrous oxide emissions from grazed grassland systems (2012).

Keywords: Athabasca River Basin, Athabasca University, CAIP Research Chair, LinkedIn, Professor Junye Wang.

An Interview with Professor Junye Wang (Part Two)^{[1],[2],[3],[4]}

*Please see the footnotes throughout the interview, and bibliography and citation style listing after the interview.*

12. What is the most effective means of teaching students through an online institution such as Athabasca University?

E-learning, digital course, and distance learning has been very important part of higher education. An online course could aim at unlimited participation and open access via the web. In addition to traditional course materials such as filmed lectures, readings, and problem sets, a massive open online course can provide interactive user forums to support community interactions between students, professors, and teaching tutors. AU is internationally a leader in open and distance education. AU is dedicated to the removal of barriers that restrict access to and success in university-level study and to increasing equality of educational opportunity for adult learners worldwide through widely researched development in distance education, such as mobile learning, multi-media, and online activities.

13. What benefits come to the professor-researcher such as yourself?

My basic research is on multi-scale and multidisciplinary modelling. The CAIP program provides long-term funding so that I can focus on development of an ambitious framework: the modelling framework of integrated terrestrial and aquatic systems.

14. According to LinkedIn, circa 2015, you self-describe, as follows:

Junye’s research mainly focus on energy, environment and sustainability. [He] has over 30 year experience of multi-scale and multidisciplinary modeling and is internationally recognized as a leader in energy, environment and sustainability. His research program is aimed at integrating agroecosystem, land use change and Geographic Information System (GIS) to assess environmental impacts of expanding biogas, bioenergy crops and land use change with emphasis on their interactions. He has developed various modeling and simulation of various physical, chemical and biological systems using various numerical and empirical approaches, such as lattice Boltzmann method (LBM) and computational fluid dynamics (CFD) and agroecosystem modelling (IPCC and process-based approaches) with a broad range of applications, such as agroecosystems, soil carbon sequestration, greenhouse gas emission and mitigation, nutrient cycling, water and hydrology, fuel cells/microbial fuel cells, thermofluid systems, porous media and bioenergy. His researches were highlighted by governments and organisations, such as European Commission in Science for Environment Policy, Earth Emphasis and Renewable Energy Global Innovation. He looks to expand capacity of agroecosystem modeling and computational sustainability to develop an integrated framework for assessment of environmental impacts of unconventional oil and gas (oil sands and hydraulic fracturing) production on agroecosystem and identify key factors of the cumulative effects for watershed management across Alberta and Canada. He has authored about 50 refereed journal papers and serves associate editor and editorial board member of several international journals. He is a reviewer of papers for about 40 journals and a reviewer of proposals and final reports for three research councils in the UK (EPSRC, NERC and ESRC).^[5]

What does this breadth of experience bring to the educational and research work at Athabasca University?

A river basin is a complex system of physical, chemical and biological processes. Any single method is insufficient to build such an ambitious research hub and infrastructure. It is necessary to integrate multiple approaches and disciplines for establishing a relationship between physical, chemical and biological processes that reflects real-world problems. I have the unique background and experience of various modelling methods, from high-resolution numerical approaches such as the lattice Boltzmann method (LBM) and computational fluid dynamics (CFD) (e.g., PHYSICA multi-physics package and the Rolls-Royce HYDRA CFD code) to process-based models (e.g., DNDC and Roth-C). As a professional modeller, I have a strong experience of a variety of numerical methods and an exceptional ability to select the most suitable approach for a specific real-world problem and to integrate numerical methods for their mutual enhancement. Thus, my expertise and experience make it easier to adopt a whole systems approach and multidisciplinary collaboration to study dynamic interactions of nutrients, water, energy, pollutants, human activities and land-use management in river basin research. On the other hand, my experience and expertise in multidisciplinary and interdisciplinary integration and collaboration, can promote research-driven teaching and learning at AU. A cutting-edge research usually requires students to face various challenges. Thus, it is an excellent opportunity for students to acquire skills of critical thinking and problem-solving through the real problems-driven learning.

15. You have authored a number of articles including Domain-decomposition method for parallel lattice Boltzmann simulation of incompressible flow in porous media(2005),Flow simulation in a complex fluidics using three turbulence models and unstructured grids (2009), Development and application of a detailed inventory framework for estimating nitrous oxide and methane emissions from agriculture (2011), Theory of flow distribution in manifolds (2011), Modelling nitrous oxide emissions from grazed grassland systems (2012), Discrete approach for flow field designs of parallel channel configurations in fuel cells (2012), Pressure drop and flow distribution in a mini-hydrocyclone group: UU-type parallel arrangement (2013), Barriers of scaling-up fuel cells: Cost, durability and reliability (2015), and Theory and practice of flow field designs for fuel cell scaling-up: A critical review (2015)^{[6],[7],[8],[9],[10],[11],[12],[13],[14]}Before exploration of these particular articles, what core theme unites these research articles, and, more generally, their respective topics and sub-topics?

These articles are on various topics from chemical engineering and energy, to environment and biogeochemical processes. A core theme is on energy, environment and sustainability. The world consists of fluid and solid. Despite very different phenomena in the real world, they are all essentially interactions between fluids, solids or fluid and solid, which are controlled by three transports (mass, energy and momentum) and two reactions (chemical and biological). These articles are to establish relationships between the three transports and the two reactions for different real-world problems using various analytical and numerical methods.

16. Domain-decomposition method for parallel lattice Boltzmann simulation of incompressible flow in porous media(2005) describes the lattice Boltzmann method for the simulation of flow in porous media, and a “cell-based domain-decompositions method for the parallel lattice Boltzmann simulation of flow in porous media.”^[15] It relates to parallel or high performance computation. What are the advantages in this method? How was this cell-based domain-decompositions method utilized in this paper?

A personal computer does not have capacities to complete a large scale simulation in time. Parallel computation is a type of computation in which a big job of simulation is divided uniformly into many smaller ones. Then, these smaller jobs are distributed on many CPUs. Thus, many calculations are carried out simultaneously, operating on the principle that each CPU takes approximate job load. Therefore, it is central in the parallel computation how a big job is divided uniformly into many smaller ones, which is called “domain-decompositions.” The algorithm of the cell based domain decomposition is a generalized method of domain-decompositions for complex geometries. It has the following advantages: i) automatically decomposes a complex flow domain, ii) optimizes computer memory using sparse matrix that only store fluid cells, iii) exact load balance, iv) simple communication pattern and nearest communication connection among processors, and v) high parallel efficiency in agreement with the theoretical efficiency. Therefore, the algorithm is flexible, efficient and reliable for modeling flow in any complex geometry and is superior to other similar methods for complex geometries.

17. What seem like some of the pragmatic implications for implementation to research on the Athabasca River Basin?

Ensuring sustainable resource development is a top priority of Alberta strategic plans. The development of next generation modeling tools is key to drive new and deeper understanding in terrestrial and aquatic systems for sustainable resource management. Such an analysis of the real system such as the Athabasca River Basin based on the multidisciplinary and interdisciplinary research and integration will enforce systematic, quantitative and comprehensive clarification of concepts and assumptions and impose rational methods for approaching the problem of sustainable resource development and management in a river basin. It is likely that the research results will offer new approaches and improved technologies to achieve sustainable resource development and management in the Athabasca River Basin system.

18. Flow simulation in a complex fluidics using three turbulence models and unstructured grids(2009) aimed to simulate “symmetrical turn-up vortex amplifier (STuVA)” for the maximal flow-rate of an “eight-port STuVA.”^[16] The paper described the utilization for the methodology as 3 turbulence models known as the standard k-epsilon”, the renormalization group (RNG) k-epsilon ” model and the Reynolds stress model (RSM)”; wherein, each of them has simulated flow in an eight-port STuVA for maximum flow minus swirling in the flow. From this, the article compared, or better contrasted, with the flow rate in ambient conditions. RSM appeared to match the experimental observations and measurements more than RNG and the standard k-epsilon How can research in different models of flow rate be utilized in the Athabasca River Basin – in practical terms?

Fluid mechanics is fundamental to studies of hydrological processes. The computational fluid dynamics (CFD) is a high-resolution method of fluid mechanics to simulate three transports (mass, energy and momentum) and two reactions (chemical and biological). Though the background of this article is on STuVA, the three turbulence models and numerical algorithms of the CFD in this paper are the same as those of various industrial and hydrological problems. In practice, there have been many applications of the CFD in hydrological modelling, such as coast wave modelling, flooding and flume diffusion. Therefore, the CFD is not unsuitable for the watershed modelling but computers lack sufficient power and memory. At least the numerical treatments and algorithms of the CFD can inspire our thinking in the watershed modelling during simplifying hydrological models.

19. In Development and application of a detailed inventory framework for estimating nitrous oxide and methane emissions from agriculture (2011)²⁰, the team utilized Intergovernmental Panel on Climate Change (IPCC) default or country-specific emission factors (EFs) with census data from England, Northern Ireland, Scotland, and Wales to develop a detailed inventory framework for the estimation of nitrous oxide (N₂O)and methane (CH₄).^[17]This framework was used to calculate the mean annual emissions of CH₄ and N₂O from crops and livestock, as well as  leaching or runoff for nations bound within the United Kingdom. What other findings came from this research?

The UK ratified the United Nations Framework Convention on Climate Change (UNFCCC) in December 1993 and the Convention came into force in March 1994. Parties to the Convention are committed to developing, publishing and regularly updating national inventories of GHG emissions. The inventory framework was constructed to resolve local differences and regional heterogeneity. Thus, local-level EFs were replaced easily using either local-specific EFs (Tier 2) or more complex ones from process-based models (Tier 3). Here we demonstrated a capability of the present framework for the estimate of a national inventory with four country-level resolution. The emissions from England, Wales, Scotland and Northern Ireland, were estimated separately using the IPCC approach. The total emission from the four countries was aggregated to the U.K. national total. Although the framework was illustrated using four country-level data, it is easy to be extended to higher resolution without any code structural change. Furthermore, it is ready to integrate with Geographic Information System (GIS) to resolve spatial variation and map emissions pattern.

20. What extrapolations remain relevant to the current condition of average annual emissions in the United Kingdom from 2011 to the present, and in the next decade?^[18]

The IPCC inventory approach is simple, comparable, transparent and global coverage for estimate of GHG inventory. The IPCC inventory is based on statistical approach to report national greenhouse gas (GHG) with a view to providing internationally acceptable inventory methodologies. Therefore, the IPCC inventory is not for prediction of GHGs but for reporting national GHG emissions though IPCC inventory allows different policy options and different land-use to be compared and to be evaluated.

21. Theory of flow distribution in manifolds (2011) delineates the theory of flow distribution and pressure drop in the prediction of dynamic performance and efficiency for manifold systems which occurred within the methodological and the theoretical models.^[19]The paper unified existing models, momentum theory, Bernoulli theory, and discrete & continuum models – a novel generalised model without a concomitant neologism. End result: a user-friendly design tool to evaluate the interaction among structures, operational conditions, and manufacture “tolerance.” Could this model become more generalized through incorporation of more (disparate) models?

Flow distribution in manifolds is fundamental issue of fluid mechanics and encounters in a wide range of areas, from radial flow reactors in chemical engineering and boiler header in mechanical engineering, to fuel cells in energy engineering and irrigation in agricultural engineering. In the past fifty years, hundreds of different models have been developed for flow distribution in manifolds that are scattered in different areas. However, some models are empirical and most of all the existing models are only suitable for some specific flow region or specific manifold structure. A generalized theory is suitable for all the flow conditions and more general manifold structure, but it is a well-known challenge to develop a generalized theory in the past fifty years.  The point is not to incorporate more models in manifolds, but to solve the practical problem of flow distributions. This theory has included the main models and methods that have been developed in the past fifty years. In other words, these existing models and methods become a special case of this generalized theory.

22. Would this greater generality create more or less functionality?

No, this generality is not to create more or less functionality, but to be useful for more structures and operating conditions.

23. In Discrete approach for flow field designs of parallel channel configurations in fuel cells (2012), the paper describes the difficulty, the problem, in transformation of single, or multiple, laboratory scale fuel cells into industrial scale production for mass utility, which involves a number of problems to maintain “throughput, operating life, low cost, reliability and high efficiency in R&D offuelcells.”^[20]You intended the research to find a uniform flow distribution and pressure drop in a homogenous, or parallel, set of channel setups, or “configurations.”^[21] How did the “present approach” improve upon the performance of “different layout configurations, structures, and flow conditions”?^[22]

The upscaling of fuel cells is based on a basic assumption of repeat units that a successful cell performance can be repeated by all other cells in the stack since they use the same materials, seals, catalyst and structures, and undertake the same electrochemical processes. This means that the issues of chemistry, materials, water, and heat have been solved in a single cell scale. For this type of designs using repeat units, the uniformity of the flow distribution in a manifold system often determines efficiency, durability and cost of the unit stack. Under the ideal operating conditions, the electrochemical reaction is uniform over all the cells and the efficiency of the fuel cell stack is the highest and its reliability and durability is comparable to that of its individual cell. Therefore, the development of the theoretical model is to evaluate if the performance of a successful cell is repeated by all other cells in the fuel cell stack and if all the cells in the stack operate in the same operating conditions, such as flow rates and pressure drops. Thus, a design can be improved by optimization of flow conditions and structure.

Appendix I: Footnotes

[1] Professor and CAIP Chair, Science and Technology, Athabasca University.

[2] Individual Publication Date: February 1, 2016 at http://in-sightjournal.com/2016/02/01/an-interview-with-professor-junye-wang-part-two/; Full Issue Publication Date: May 1, 2016 at http://in-sightjournal.com/2016/02/01/an-interview-with-professor-junye-wang-part-two/.

[3] Ph.D. (1993 – 1996), Chemical Engineering and Mechanical Engineering, East China University of Science and Technology; M.Sc. (1986 – 1989), Aerospace, Aeronautical and Astronautical Engineering, Harbin Shipbuilding Engineering Institute.

[4] Photograph courtesy of Professor Junye Wang.

[5] Please see LinkedIn. (2015). Junye Wang. Retrieved from https://ca.linkedin.com/pub/junye-wang/15/a87/a87.

[6] Please see Wang, J., Zhang, X., Bengough, A. G., & Crawford, J. W. (2005). Domain-decomposition method for parallel lattice Boltzmann simulation of incompressible flow in porous media. Physical Review. E, Statistical, Nonlinear, And Soft Matter Physics, 72(1 Pt 2), 016706.

[7] Please see Junye, W., & Geoffrey H., P. (2009). Flow simulation in a complex fluidics using three turbulence models and unstructured grids. International Journal Of Numerical Methods For Heat & Fluid Flow, 19(3/4), 484-500.

[8] Please see Wang, J., Cardenas, L. M., Misselbrook, T. H., & Gilhespy, S. (2011). Development and application of a detailed inventory framework for estimating nitrous oxide and methane emissions from agriculture. Atmospheric Environment, 45(7), 1454-1463. doi:10.1016/j.atmosenv.2010.12.014

[9] Please see Wang, J. (2011). Theory of flow distribution in manifolds. Chemical Engineering Journal, 168(3), 1331-1345. doi:10.1016/j.cej.2011.02.050

[10] Please see Wang, J., Cardenas, L. M., Misselbrook, T. H., Cuttle, S., Thorman, R. E., & Li, C. (2012). Modelling nitrous oxide emissions from grazed grassland systems. Environmental Pollution, 162223-233. doi:10.1016/j.envpol.2011.11.027

[11] Please see Wang, J., & Wang, H. (2012). Discrete approach for flow field designs of parallel channel configurations in fuel cells. International Journal Of Hydrogen Energy, 37(14), 10881-10897. doi:10.1016/j.ijhydene.2012.04.034

[12] Please see Huang, C., Wang, J., Wang, J., Chen, C., & Wang, H. (2013). Pressure drop and flow distribution in a mini-hydrocyclone group: UU-type parallel arrangement. Separation & Purification Technology, 103139-150. doi:10.1016/j.seppur.2012.10.030

[13] Please see Wang, J. (2015). Barriers of scaling-up fuel cells: Cost, durability and reliability. Energy, 80509-521. do

i:10.1016/j.energy.2014.12.007.

[14] Please see Wang, J. (2015). Theory and practice of flow field designs for fuel cell scaling-up: A critical review. Applied Energy,157640-663. doi:10.1016/j.apenergy.2015.01.032

[15] Please see Wang, J., Zhang, X., Bengough, A. G., & Crawford, J. W. (2005). Domain-decomposition method for parallel lattice Boltzmann simulation of incompressible flow in porous media. Physical Review. E, Statistical, Nonlinear, And Soft Matter Physics, 72(1 Pt 2), 016706.

[16] Please see Junye, W., & Geoffrey H., P. (2009). Flow simulation in a complex fluidics using three turbulence models and unstructured grids. International Journal Of Numerical Methods For Heat & Fluid Flow, 19(3/4), 484-500.

[17] Please see Wang, J., Cardenas, L. M., Misselbrook, T. H., & Gilhespy, S. (2011). Development and application of a detailed inventory framework for estimating nitrous oxide and methane emissions from agriculture. Atmospheric Environment, 45(7), 1454-1463. doi:10.1016/j.atmosenv.2010.12.014

[18] Please see Wang, J., Cardenas, L. M., Misselbrook, T. H., & Gilhespy, S. (2011). Development and application of a detailed inventory framework for estimating nitrous oxide and methane emissions from agriculture. Atmospheric Environment, 45(7), 1454-1463. doi:10.1016/j.atmosenv.2010.12.014

[19] Please see Wang, J. (2011). Theory of flow distribution in manifolds. Chemical Engineering Journal, 168(3), 1331-1345. doi:10.1016/j.cej.2011.02.050

[20] Please see Wang, J., & Wang, H. (2012). Discrete approach for flow field designs of parallel channel configurations in fuel cells. International Journal Of Hydrogen Energy, 37(14), 10881-10897. doi:10.1016/j.ijhydene.2012.04.034

[21] Please see Wang, J., & Wang, H. (2012). Discrete approach for flow field designs of parallel channel configurations in fuel cells. International Journal Of Hydrogen Energy, 37(14), 10881-10897. doi:10.1016/j.ijhydene.2012.04.034

[22] Please see Wang, J., & Wang, H. (2012). Discrete approach for flow field designs of parallel channel configurations in fuel cells. International Journal Of Hydrogen Energy, 37(14), 10881-10897. doi:10.1016/j.ijhydene.2012.04.034

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