In the field of fluid engineering, controlling turbulent flows remains a crucial problem. This paper presents a basis of numerical methods and turbulence models for the large Eddy simulation. Simulation results include the unsteady analyses of complex flows, such as the vortex dynamics of turbulent jets subject to inlet perturbations and the reacting flow with flame propagation in a gas–turbine...

We prove instability of a part of a branch of viscous incompressible fluid flows induced by a shrinking sheet. These flows are exact solutions of the Navier-Stokes equation.

A system of equations for averaged velocity of turbulent motion of ideal fluid is derived from the assumption that this motion is ergodic. Several fluid flows are considered. A remarkable feature of the averaged equations is that in some cases they have a form of an eigenvalue problem similar to that for Schrődinger’s equation. The equations derived suggest that there are no universal equations...

– The lattice Boltzmann algorithm efficiently simulates the Navier Stokes equation of isothermal fluid flow, but ignores thermal fluctuations of the fluid, important in mesoscopic flows. We show how to adapt the algorithm to include noise, satisfying a fluctuation-dissipation theorem (FDT) directly at lattice level: this gives correct fluctuations for mass and momentum densities, and for stress...

Distributive fluid mixing in laminar flows is studied using the concept of concentration distribution mapping matrices, which is based on the original ideas of Spencer & Wiley [1], describing the evolution of the composition of two fluids of identical viscosity with no interfacial tension. The flow domain is divided into cells, and large-scale variations in composition are tracked by following ...

A new and very general technique for simulating solid-fluid suspensions is described; its most important feature is that the computational cost scales linearly with the number of particles. The method combines Newtonian dynamics of the solid particles with a discretized Boltzmann equation for the fluid phase; the many-body hydrodynamic interactions are fully accounted for, both in the creeping-...

In this paper, we discuss a previously unknown selection principle of optimal viscous configurations for immiscible multi-fluid Hele-Shaw flows that have emerged from numerical experiments on threeand four-layer flows. Moreover, numerical investigation on four-layer flows shows evidence of four-layer systems which are almost completely stabilizing. Simple physical mechanisms that explain both o...

This paper summarizes the current efforts at VKI and collaborating institutions in understanding nonequilibrium phenomena in hypersonic flows. Research activities related to “Detailed gas chemistry models,” “Kinetic theory,” and “Rarefied gas effects” are described. Keywords— Atmospheric entry flows, Thermo-chemical nonequilibrium flows, Computational Fluid Dynamics.

The understanding of polymeric fluids flows is of essential importance for several industry sectors, including plastic and food processing industries. The rheological response of viscoelastic fluids is quite complex, including combination of viscous and elastic effects and highly non-linear viscous and elastic phenomena. In a previous work we presented a solver for internal viscoelastic fluid f...

Statistical mechanics of three-dimensional flows of an ideal incompressible fluid is considered. An ideal fluid differs from the usual Hamiltonian systems of statistical mechanics by possessing an infinite number of integrals of motion that are circulations of velocity over closed fluid contours. To reduce the problem to a standard one, the governing equations should be written in a Hamiltonian...