Simulating fluid flow at micro level is an ongoing problem. Simplified macroscopic flow models like Darcy’s law is unable to estimate fluid dynamic properties of porous media. The digital sample reconstruction by high resolution X-ray computed tomography scanning and fluid-dynamics simulation, together with the increasing power of super-computers, allow to carry out pore-scale simulations throu...

High-order simulation of flows containing shock waves is an extremely difficult task due to the discontinuous changes in flow properties across the shock. The present work investigates a shock-detecting sensor for filtering of high-order compact finitedifference schemes to examine the shock-capturing in direct simulation of NavierStokes solver. Based on the accuracy and minimum dissipation erro...

A somewhat limited number of computationally tractable methods of simulating turbulent premixed combustion currently exist. Most of these methods either directly or indirectly require information about how fast flames propagate in turbulent flow fields. In this work a dynamic model for describing turbulent burning velocities in the context of large eddy simulation (LES) is presented. This model...

Abstract This study investigates a re-entry scenario of an Apollo-like space capsule with Direct Numerical Simulations (DNS). The simulation includes the chemical equilibrium gas model. Cross-flow-like vortices are induced through random distributed roughness patches on surface. Two different machine learning methods used to predict maximum vorticity magnitude downstream pseudo-random patch, wa...

Apparent inconsistency between (i) experimental and direct numerical simulation (DNS) data that show the significant influence of differential diffusion on turbulent burning rate (ii) recent complex-chemistry DNS indicate mitigation conditioned profiles various local flame characteristics at high Karlovitz numbers, is explored by analysing new obtained from lean hydrogen–air flames. Both aforem...

Two-dimensional direct numerical simulation (DNS) databases of bluff-body-stabilized lean hydrogen flames representative complicated reactive–diffusive system are analysed using the combined approach computational singular perturbation (CSP) and tangential stretching rate (TSR) to investigate chemical characteristics in blow-off dynamics. To assess diagnostic approaches flame dynamics, Damköhle...

Combustion of a single, resolved carbon particle is studied using novel numerical approach that makes use an overset grid. The model implemented into the framework compressible Direct Numerical Simulation (DNS) code. A method to artificially reduce speed sound presented. For Mach numbers lower than ?0.1 this may dramatically improve efficiency without affecting any physical aspects except for a...

The subgrid-scale (SGS) modeling of helical, isotropic turbulence in large eddy simulation is investigated by quantifying rates of helicity and energy cascade. Assuming Kolmogorov spectra, the Smagorinsky model with its traditional coefficient is shown to underestimate the helicity dissipation rate by about 40%. Several two-term helical models are proposed with the model coefficients calculated...