CaltechAUTHORS: Conference Item
https://feeds.library.caltech.edu/people/Blanquart-G/conference_item.rss
A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenThu, 23 May 2024 19:18:12 -0700Numerical Modeling and Analysis of Early Shock Wave Interactions with a Dense Particle Cloud
https://resolver.caltech.edu/CaltechAUTHORS:20190712-112323497
Year: 2012
DOI: 10.2514/6.2012-3161
Dense compressible multiphase flows exist in variable phase turbines, explosions, and fluidized beds, where the particle volume fraction is in the range 0.001 < α_d < 0.5. A simple model problem that can be used to study modeling issues related to these types of flows is a shock wave impacting a particle cloud. In order to characterize the initial shock-particle interactions when there is little particle movement, a two-dimensional (2-D) model problem is created where the particles are frozen in place. Qualitative comparison with experimental data indicates that the 2-D model captures the essential flow physics. Volume-averaging of the 2-D data is used to reduce the data to one dimension, and x-t diagrams are used to characterize the flow behavior. An equivalent one-dimensional (1-D) model problem is developed for direct comparison with the 2-D model. While the 1-D model characterizes the overall steady-state flow behavior well, it fails to capture aspects of the unsteady behavior. As might be expected, it is found that neglecting the unclosed fluctuation terms inherent in the volume-averaged equations is not appropriate for dense gas-particle flows.https://resolver.caltech.edu/CaltechAUTHORS:20190712-112323497Equilibrium geometries and binding energy scaling relationships for aromatic excimers and exciplexes: A TDDFT and NEVPT2 study
https://resolver.caltech.edu/CaltechAUTHORS:20170913-074933931
Year: 2017
Gas phase assocn. of polyarom. hydrocarbons (PAHs) is thought to play a key role in processes ranging from soot formation to cosmic dust growth. While small PAHs such as benzene and pyrene form relatively weakly bound van der Waals complexes in the ground state, significantly stronger binding has been obsd. in the first singlet excited state. Time-dependent d. functional theory (TDDFT) has proven an accurate and efficient method of calcg. excited state energies. However, the importance of static correlation in PAH systems means that multireference methods are often required for qual. accurate descriptions of excited states. In this work, benchmark binding energies are computed for the benzene excimer using a range of TDDFT hybrid and double hybrid functionals. Results are compared against multireference complete active space SCF (CASSCF) results with second-order n-electron valence state perturbation theory (NEVPT2) correction. Scaling relationships between dimer carbon atoms and binding energy are established using both TDDFT and NEVPT2 methods, allowing estn. of binding energy for large PAH excimers, for which multireference calcns. are not feasible. Complete potential energy surfaces are constructed for the benzene-naphthalene and the naphthalene-anthracene heterodimeric exciplexes at the double hybrid TDDFT level. The results allow a direct comparison of binding energy scaling and equil. geometry for homodimeric and heterodimeric complexes. They also provide a starting point for the statistical mech. anal. required for a complete understanding of PAH binding thermodn. and kinetics.https://resolver.caltech.edu/CaltechAUTHORS:20170913-074933931