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Ryan W. Houim

Publications and source records attributed to Ryan W. Houim.

2 recordsLinked to original sources

A robust high-resolution algorithm for quadrature-based moment methods applied to high-speed polydisperse multiphase flows

A high-resolution Eulerian method for simulating high-speed polydisperse granular multiphase flows has been developed. The governing equations include a compressible gas that is coupled to mass-based moment equations for a polydisperse granular flow derived from the generalized population balance equation. The model includes effects from particle collisions, drag, convective heat transfer, particle-fluid-particle pressure, and finite-size particle force terms. The mass moment integrals are closed using the generalized quadrature method of moments to allow for continuous size distributions. The governing equations are solved by using high-resolution reconstruction schemes and results from decoupled Riemann problems for the gas and particles as each quadrature node. Success of the technique is demonstrated through a variety of numerical experiments including polydisperse multiphase Riemann shock-tube problems, shock--particle-curtain interactions, dust layer dispersal, dust layer dispersal by shock waves, and dispersal of spherical particle shells by high-pressure gas.

physics.flu-dyn

A Technique for Computing Dense Granular Compressible Flows with Shock Waves

A numerical procedure was developed for solving equations for compressible granular multiphase flows in which the particle volume fraction can range dynamically from very dilute to very dense. The procedure uses a low-dissipation and high-order numerical method that can describe shocks and incorporates a particulate model based on kinetic theory. The algorithm separates edges of a computational cell into gas and solid sections where gas- and granular-phase Riemann problems are solved independently. Solutions from these individual Riemann problems are combined to assemble the fully coupled convective fluxes and nonconservative terms for both phases. The technique converges under grid refinement even with very high volume fraction granular interfaces. The method can advect sharp granular material interfaces that coincide with multi-species gaseous contact surfaces without violating the pressure nondisturbing condition. The procedure also reproduces known features from multiphase shock tube problems, granular shocks, transmission angles of compaction waves, and shock wave and dust-layer interactions. This approach is relatively straightforward to use in an existing code based on Godunov's method and can be constructed from standard compressible solvers for the gas-phase and a modified AUSM$^+$-up scheme for the particle phase.

physics.comp-ph