High-order methods have demonstrated their potential in large eddy simulations (LES) of turbulent flows with relatively low Reynolds numbers. The cost becomes a serious limiting factor for high Reynolds number problems. A promising approach to reduce the cost of these simulations is the hybrid Reynolds-Averaged Navier-Stokes (RANS)/LES approach. In this paper, a new hybrid RANS-Implicit LES (IL...

ven with great advances in computational techniques and computing power during recent decades, the modeling of unsteady separated flows, such as those encountered in the wake of a re-entry vehicle, continues to be one of the most challenging problems in CFD. Of most interest to the aerothermodynamics community is accurately predicting transient heating loads on the base of a blunt body, which w...

A novel method is proposed for blending RANS and VMS-LES approaches in a hybrid model. To this purpose, the ow variables are decomposed in a RANS part (i.e. the averaged ow eld), a correction part that takes into account the turbulent large-scale uctuations, and a third part made of the unresolved or SGS uctuations. The basic idea is to solve the RANS equations in the whole computational domain...

To overcome this difficulty, various hybrid LES/RANS approaches have been developed, where RANS (Reynolds-averaged Navier-Stokes) equations are solved in the near-wall region while LES is only conducted in the free-shear region away from the wall [Fröhlich and von Terzi 2008]. One of the methods to address this issue is a consistent framework for turbulence modeling, where the filtered and Reyn...

We discuss the development of a simplified model for the jet noise source that can be used in practical predictions of installed noise. In the proposed scheme, the source is prescribed on a radiator surface defining the boundary between the inner rotational jet flow and the outer linear pressure field. The source consists of wavepacket-type partial fields whose noise propagation can be computed...

The paper evaluates a new method to prescribe synthesized turbulent inlet boundary conditions. The method can also be used when prescribing turbulent fluctuations at an interface between (U)RANS and LES regions when the flow enters the LES region. When making LES, DES or hybrid LES-RANS a precursor channel DNS is often used. The disadvantage of this method is that it is difficult to re-scale th...

The numerical flow prediction of highly complex flow systems, such as the aerothermal flow through an entire aircraft gas turbine engine, requires the application of multiple specialized flow solvers, which have to run simultaneously in order to capture unsteady multicomponent effects. The different mathematical approaches of different flow solvers, especially large eddy simulation (LES) and Re...

Ñ Large-Eddy Simulation of In-Cylinder Flows Ñ Advances in physical models, numerical methods, and computational power together have brought large-eddy simulation (LES) to the point where it warrants serious consideration for computing in-cylinder turbulent flows. This article includes: a discussion of LES and how it differs from Reynolds-averaged Navier Stokes (RANS) modeling; motivation for t...

Large Eddy Simulation (LES) is an effective intermediate approach between DNS and RANS, capable of simulating flow features which cannot be handled with RANS such as significant flow unsteadiness and strong vortex-acoustic couplings, and providing higher accuracy than RANS at reasonable cost but still typically an order of magnitude more expensive. Desirable modeling choices involve selecting a...

Nowadays there are wide possibilities to perform numerical studies of turbulent natural convection flows on the base of 3D unsteady formulations [1]. Direct Numerical Simulation (DNS) is the most attractive and reliable approach for getting a detailed knowledge on convection [2, 3]. However, DNS applications are practically limited by the case of simplified geometry and/or the Rayleigh numbers ...