Gas-particle flows in fluidized beds and circulating fluidized beds are inherently unstable, and they manifest fluctuations in velocities and local suspension density over a wide range of length and time scales. In riser flows, these fluctuations are associated with the random motion of the individual particles and with the chaotic motion of particle clusters. Coarse-grid simulations for indust...

We evaluate the effects of solid particle rotation in high-altitude solid rocket exhaust plume flows, through the development and application of methods for the simulation of two phase flows involving small rotating particles and a nonequilibrium gas. Green’s functions are derived for the force, moment, and heat transfer rate to a rotating solid sphere within a locally free-molecular gas, and i...

Vertical pneumatic transport in a lab-scale vertical lifter has been studied using Laser Doppler Anemometry (LDA). The experimental system consists of a lower fluidized silo, an upper receiving tank and a connecting vertical transport pipe made of clear glass. The experimental study has been performed in order to get detailed information of the complex gas-particle flow behavior in a dilute ver...

In this paper, computational fluid dynamics (CFD) is utilized to characterize a prototype biolistic delivery system, the biomedical device based on the contoured-shock-tube design (CST), with the aim at investigating shocks induced flow instabilities within the contoured shock tube. The shock/interface interactions, the growth of perturbation at an interface between two fluids of different dens...

The classical Bondi-Hoyle formula gives the accretion rate onto a point particle of a gas with a uniform density and velocity. However, the Bondi-Hoyle problem considers only gas with no net vorticity, while in a real astrophysical situation accreting gas invariably has at least a small amount of vorticity. We therefore consider the related case of accretion of gas with constant vorticity, for ...

Dense gas-particle flows are encountered in a variety of industrially important processes for large-scale production of fuels, fertilizers and base chemicals. The scale-up of these processes is often still problematic, which can be related to the intrinsic complexities of these flows, which are unfortunately not yet fully understood despite significant efforts made in both academic and industri...

In this paper, the gas-kinetic BGK scheme for the compressible flow equations is extended to chemical reactive flow. The mass fraction of the unburnt gas is implemented into the gas kinetic equation by assigning a new internal degree of freedom to the particle distribution function. The new variable can be also used to describe fluid trajectory for the nonreactive flows. Due to the kinetic gove...