Multiscale block spectral solution for unsteady flows

Multiscale Feature Detection in Unsteady Separated Flows

Very complex flow structures occur during separation that can appear in a wide variety of applications involving flow over a bluff body. This study examines the ability to detect the dynamic interactions of vortical structures generated from a Helmholtz instability caused by separation over bluff bodies at large Reynolds number of approximately 104 based on a cross stream characteristic length ...

Variable high-order multiblock overlapping grid methods for mixed steady and unsteady multiscale viscous flows, part II: hypersonic nonequilibrium flows

The variable high-order multiblock overlapping (overset) grids method of Sjögreen & Yee (CiCP, Vol.5, 2008) for a perfect gas has been extended to nonequilibrium flows. This work makes use of the recently developed high-order well-balanced shock-capturing schemes and their filter counterparts (Wang et al., J. Comput. Phys., 2009, 2010) that exactly preserve certain non-trivial steady state solu...

Unsteady Flows in Turbines

Unstructured Adaptive Moving Mesh Solution of Unsteady Shear Flows and Free-surface Flows

A method for performing anisotropic unstructured mesh adaptation is discussed that is well suited for computational fluid dynamics on parallel distributed memory computers. This algorithm which involves mesh motion, rather than refinement and coarsening, is fast, parallel, and fully conservative. The approach is effective at accurately capturing free-surface flows, boundary layers, and unsteady...

Optimizing lattice Boltzmann simulations for unsteady flows

We present detailed analysis of a lattice Boltzmann approach to model time-dependent Newtonian flows. The aim of this study is to find optimized simulation parameters for a desired accuracy with minimal computational time. Simulation parameters for fixed Reynolds and Womersley numbers are studied. We investigate influences from the Mach number and different boundary conditions on the accuracy a...