Temporally regularized direct numerical simulation

A computational strategy for the regularized 13 moment equations with enhanced wall-boundary conditions

The challenge of modeling low-speed rarefied gas flow in the transition regime is well known. In this paper, we propose a numerical solution procedure for the regularized 13 moment equations within a finite-volume framework. The stress and heat flux equations arising in the method of moments are transformed into the governing equations for the stress and heat flux deviators based on their first...

Stability of Temporally-Evolving Supersonic Boundary Layers over Micro-Cavities for Ultrasonic Absorptive Coatings

Ultrasonic absorptive coatings, consisting of regularly-spaced arrays of micro-cavities, have previously been shown to effectively damp second-mode instability for the purpose of delaying transition in hypersonic boundary layers. However, previous simulations and stability analysis have used approximate porous-wall boundary conditions. Here we investigate the feasibility of using direct numeric...

Modeling Rayleigh-Taylor Instability of a Sedimenting Suspension Arising in Direct Numerical Simulation

In this paper we study the sedimentation of 6400 circular particles in 2D using the method of distributed Lagrange multipliers for solid-liquid flow. The simulation gives rise to fingering which resembles Rayleigh-Taylor instability. The waves have a welldefined wavelength and growth rate which can be modeled as a conventional RayleighTaylor instability of heavy fluid above light. The heavy flu...

outflow Boundary Codition Issues in Direct Numerical Simulation of Three- Dimensional Plane Wake Flow

The effect of boundary conditions on the accuracy and stability of the numerical solution of fluid flows by Lattice-Boltzmann method

The aim of this study is to investigate the effect of boundary conditions on the accuracy and stability of the numerical solution of fluid flows in the context of single relaxation time Lattice Boltzmann method (SRT-LBM). The fluid flows are simulated using regularized, no-slip, Zou-He and bounce back boundary conditions for straight surfaces in a lid driven cavity and the two-dimensional flow ...