We present a detailed bifurcation scenario of zero-Prandtl number Rayleigh-Bénard convection using direct numerical simulations (DNS) and a 27-mode low-dimensional model containing the most energetic modes of DNS. The bifurcation analysis reveals a rich variety of convective flow patterns and chaotic solutions, some of which are common to that of the 13-mode model of Pal et al. [EPL 87, 54003 (...

The simulation of turbulent flames fully resolving the smallest flow scales and thinnest reaction zones goes along with specific requirements, which are discussed from dimensionless numbers useful to introduce generic context in direct numerical (DNS) is performed. Starting this basis, evolution DNS landscape over past five years reviewed. It found that geometries, focus studies overall motivat...

The direct numerical simulation of particle flows is investigated by a Lagrangian VOF approach and penalty methods of second order convergence in space for incompressible flows interacting with resolved particles on a fixed structured grid. A specific Eulerian volume of fluid method is developed with a Lagrangian tracking of the phase function while the solid and divergence free constraints are...

A study was done as part of an effort to develop computational models representing turbulent mixing under thermodynamic supercritical (here, high pressure) conditions. The question was whether the large-eddy simulation (LES) approach, developed previously for atmospheric-pressure compressible-perfect-gas and incompressible flows, can be extended to real-gas non-ideal (including supercritical) f...

In recent years, direct numerical simulation (DNS) has become a powerful tool to study the stability and transition of compressible boundary layers. The difficulty in using explicit methods for DNS of hypersonic flow is the limitation of the temporal steps since the Navier-Stokes equations are stiff for explicit numerical schemes. Due to the progress in computer techniques in recent years, one ...

We study turbulent flows in a smooth straight pipe of circular cross--section up to $Re_{\tau} \approx 6000$ using direct--numerical-simulation (DNS) the Navier--Stokes equations. The DNS results highlight systematic deviations from Prandtl friction law, amounting about $2\%$, which would extrapolate $4\%$ at extreme Reynolds numbers. Data fitting coefficient yields an estimated von K\'arm\'an ...

A study was done as part of an effort to develop computational models representing turbulent mixing under thermodynamic supercritical (here, high pressure) conditions. The question was whether the large-eddy simulation (LES) approach, developed previously for atmospheric-pressure compressible-perfect-gas and incompressible flows, can be extended to real-gas non-ideal (including supercritical) f...

in this paper, direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. microtube radius is 10 µm. the interface is tracked using volume of fluid (vof) method with continuous surface force (csf) model. the flow is solved using a finite volume scheme, based on piso algorithm. numerical simulation is performed on a axisym...

Experimental dual plane particle image velocimetry (PIV) data are assessed using direct numerical simulation (DNS) data of a similar flow with the aim of studying the effect of averaging within the interrogation window. The primary reason for the use of dual plane PIV is that the entire velocity gradient tensor and hence the full vorticity vector can be obtained. One limitation of PIV is the li...

We propose a spatial-temporal multi-fidelity Gaussian process regression framework for the fusion of flow field data with various availabilities and fidelities but not sufficiently large to train neural networks commonly encountered in fluid mechanics studies. For example, experiments lead high fidelity sparse time space, while most numerical are generally regarded as less accurate spatially te...