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Clustering of Inertial Aerosols in Homogeneously Sheared Gas

Event Type: 
Date and Time: 
Friday, June 9, 2017 - 16:15
Location: 
CTR Conference Room 103
Event Sponsor: 
Parviz Moin, Director of Center for Turbulence Research
Speaker(s): 
Mohamed Houssem Kasbaoui, PhD Candidate, Aerospace Engineering, Sibley School of Mechanical and Aerospace Engineering, Cornell University

Particle-laden flows of sedimenting small heavy solid particles or droplets in a carrier gas have strong inter-phase coupling even at low volume fractions. The slip velocity between phases leads to sustained clustering that strongly modulates the overall flow. The analysis of inertial aerosols in homogeneous shear reveals three fundamental mechanisms contributing to the formation of clusters: (1) the preferential concentration of inertial particles in the stretching regions of the flow (2) particle-trajectory crossing (PTC) and (3) a Rayleigh-Taylor instability due to the vertical stacking of particle-rich and particle-depleted regions. Simulations are conducted in Euler-Lagrange and Euler-Euler formalisms. The Euler-Lagrange simulation method, based on particle tracking, capture all three effects but suffer from lack of scalability. Euler-Euler methods, based on a kinetic description, offer better scalability but require extreme care in the presence of PTC.

Bio: 
Mohamed Houssem Kasbaoui holds a Diplome d’Ingenieur from Ecole Centrale Paris with an Applied Mathematics Major, and a Master of Science in Physics from University Paris-Sud. He joined Cornell University in 2012 to pursue a PhD Degree in Aerospace Engineering with the goal to characterize the interactions between inertial particles and turbulence in particle-laden flows. His research focuses on the role of cascading fundamental instabilities on the formation of particle clusters. In addition to the modeling efforts, Kasbaoui uses and develops extensive Computational Fluid Dynamics (CFD) tools to provide input to the models. He is co-advised by Professors Olivier Desjardins and Donald L. Koch.