Direct Numerical Simulations (DNS) of the distribution function of conformation of small axisymmetric particles is considered from a numerical point of view. The mathematical modelling of microstructured uid has to take into account (i) the e ect of the surrounding uid onto the microstructure and (ii) the e ect of the microstructures on the uid. We consider (i) the simulation of the conformatio...

1. Motivation and objectives Direct numerical simulation (DNS) of turbulent reacting flows at technically relevant high Reynolds numbers will be computationally unaffordable for the foreseeable future. Large eddy simulation (LES) represents an attractive alternative. The basic idea of LES is to resolve only the large scale motion of the flow while modeling the contribution of the small (i.e. su...

A direct numerical simulation (DNS) of an unstably stratified convective boundary layer with system rotation was performed to study top-down and bottom-up diffusion processes. In order to better understand near-wall dynamics associated with scalar diffusion in the absence of surface roughness, direct simulation is utilized to numerically integrate the governing equations that model the atmosphe...

Abstract Direct numerical simulation (DNS) of transition over a hypersonic lifting body model HyTRV developed by China Aerodynamics Research and Development Center is performed. The free-stream parameters are: the Mach number 6, unit Reynolds 10000/mm, temperature 79 K, angle attack 0, wall 300 K. Weak random blowing-and-suction perturbations in leading range are used to trigger transition. A h...

A novel method for simulating turbulent flows called Stochastic Coherent Adaptive Large Eddy Simulation (SCALES) is introduced. The theoretical basis for SCALES is presented using results from a priori testing of homogenious turbulence along with a novel Coherency Diagram of a turbulent field that physically relates Direct Numerical Simulation to different Large Eddy capturing methods, such as ...

Direct numerical simulation (DNS) has become a powerful tool in studying fundamental phenomena of laminar-turbulent transition of high-speed boundary layers. Previous DNS studies of supersonic and hypersonic boundary layer transition have been limited to perfect-gas flow over flat-plate boundary layers without shock waves. For hypersonic boundary layers over realistic blunt bodies, DNS studies ...

The application of a novel turbulent inflow generator is presented using a 3D Direct Numerical Simulation (DNS) method. For simulation the in-house 3D CFD program Free Surface 3D (FS3D) is applied, which solves the incompressible Navier Stokes Equations for flows with free surfaces using a Volume-of-Fluid (VOF) technique. Three different numerical setups are presented, demonstrating the wide ra...

Lagrangian particles with mixing can be used as direct numerical simulations DNS , large eddy simulations LES , or filtered density function FDF methods depending on conditions of the simulations. We estimate major parameters associated with the DNS, LES, and FDF regimes and demonstrate that, under certain conditions specified in the paper, simulations using different mixing models approach the...

In large-eddy simulation (LES), it is often assumed that the filter width is equal to the grid spacing. Predictions from such LES are grid-spacing dependent since any subgridscale (SGS) model used in the LES equations is dependent on the resolved flow field which itself varies with grid spacing. Moreover, numerical errors affect the flow field, especially the smallest resolved scales. Thus, pre...

One of the newest of viscoelastic RANS turbulence models for drag reducing channel flow with polymer additives is studied in different flow and rheological properties. In this model, finitely extensible nonlinear elastic-Peterlin (FENE-P) constitutive model is used to describe the viscoelastic effect of polymer solution and turbulence model is developed in the k-ϵ-(ν^2 ) ̅-f framework. The geome...