Particle-laden flows
Turbulent flows laden with nano- and micro-particles are ubiquitous in nature and in fields of energy, environmental, and chemical engineering. For instance, the particle matter (PM) yield from coal combustion can be significantly reduced through the turbulence-induced agglomeration between PM and Kaolin additive. Complex and interesting phenomena emerge when the particle dynamics in turbulence are affected by droplet evaporation, chemical reaction, heat transfer, and agglomeration/fragmentation of particles. We are particularly interested in the role of particle interactions, including both short-range contact interactions and long-range hydrodynamic/electrostatic interactions, on particle transport. The problems we are investigating include:
(1) Accurately measuring and modeling the particle-scale contact/hydrodynamic/electrostatic interactions;
(2) Agglomeration/fragmentation, migration, and deposition of particles with interactions in turbulent flows;
(3) Active control of particle dynamics through external fields.
Selected publications:
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Sheng Chen*, Pinzhuo Chen, Jianhong Fu, Drag and lift forces acting on linear and irregular agglomerates formed by spherical particles. Physics of Fluids 2022 (34), 023307.
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Pinzhuo Chen, Sheng Chen*, Mengmeng Yang, Shuiqing Li. Falling clouds of particles with finite inertia in viscous flows. Physics of Fluids 2021, 33, 033314.
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Sheng Chen*, Shuiqing Li. Collision-induced breakage of agglomerates in homogenous isotropic turbulence laden with adhesive particles. Journal of Fluid Mechanics 2020, 902, A28.
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Sheng Chen, Shuiqing Li*, Jeffrey. S. Marshall. Exponential scaling in early-stage agglomeration of adhesive particles in turbulence. Physical Review Fluids, 2019, 4 (2): 024304.
Particle-based solar thermal and energy storage technology
Concentrated solar power (CSP) technology based on solid-particle is a promising solar energy utilization technology. In particle receivers, inexpensive ceramic and silica-based solid particles are adopted as heat-transfer and thermal energy storage media and have the potential to reach temperatures exceeding 1000 degrees Celsius. Coupling the high-temperature particle receiver to a supercritical carbon dioxide (sCO2) Brayton power cycle through a particle heat exchanger could further improve the solar-to-electric efficiency. We tackle several fundamental hydrodynamic and heat transfer problems in particle receivers and heat exchangers, including
(1) Models for hydrodynamic forces and heat transfer coefficient in high-temperature gas-solid systems.
(2) Multi-scale modeling, design, and optimization of solid particle receivers and particle heat exchangers.
Publications:
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Sheng Chen*, Wenchao Fang, ShuoShi, Flow characteristics and packing structures of dense granular flow around an immersed cylindrical tube. Chemical Engineering Science, 2022.
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Jianhong Fu, Sheng Chen*, Pinzhuo Chen, Chang Wen, Particle-resolved simulation on viscous flow past random and ordered arrays of hot ellipsoidal particles. International Journal of Multiphase Flow, 2021, 142, 103736.
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Wenchao Fang, Sheng Chen*, Jingying Xu, Kuo Zeng. Predicting heat transfer coefficient of a shell-and-plate, moving packed-bed particle-to-sCO2 heat exchanger for concentrating solar power. Energy 2021, 217, 119389.
Formation and control of particulate matter from combustion
Particulate Matter (PM), which contains toxic trace elements and might pose serious risks to human health, is the primary air pollutant in China. Particulate Matter (PM) formation during combustion of solid fuels involves different mechanisms, including mineral coalescence, particle/mineral fragmentation, and vaporization−nucleation and condensation of refractory mineral elements and volatile elements. Therefore, understanding the formation mechanisms is highly challenging. We are working on PM from combustion to understand:
(1) Different pathways (vaporization−nucleation/ fragmentation /coalescence, etc) for PM formations and full-size numerical models.
(2) Reduction of PM formation during combustion by adsorption of gas-phase precursor.
(3) Particle dynamics in air pollution control devices and advanced particulate control technologies.
Selected publications:
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Mingkai Cheng, Sheng Chen*, Yu Qiao, Minghou, Xu, Role of alkali chloride on formation of ultrafine particulate matter during combustion of typical food waste. Fuel 2022 (315), 123153.
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Sheng Chen, Mingkai Cheng, Jingying Xu*, Xiaowei Liu, Dunxi Yu, and Minghou Xu, Numerical Analysis on Reduction of Ultrafine Particulate Matter by a Kaolin Additive during Pulverized Coal Combustion. Energy & Fuels 2021, 35(11), 9538-9549
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Sheng Chen, Wenwei Liu, and Shuiqing Li*. Effect of long-range electrostatic repulsion on pore clogging during microfiltration. Physical Review E, 2016, 94(6),063108.