The paper presents a comparison of several hybridization between RANS and LES, and their potential and limitations in an industrial context. The first part of the paper addresses an often eluded problem in the hybrid RANS/LES community: the importance of the baseline statistical model. A new robust low-Reynolds number eddy-viscosity model, derived from a Reynolds-stress model and accounting for...

The objective of this study is to evaluate a recently proposed dynamic hybrid Reynoldsaveraged Navier-Stokes (RANS)-Large Eddy Simulation (LES) modeling framework that seeks to effectively address issues regarding RANS-to-LES transition and explicit grid dependence inherent in most current hybrid RANS-LES (HRL) models. RANSto-LES transition in the investigated dynamic HRL (DHRL) model is based ...

A new wall model for LES is proposed. Unlike conventional zonal approaches, given Reynolds stresses are not imposed as the solution, but used as constraints on the SGS stress so that the given Reynolds stress closely matches the computed one only in the mean sense. Also, since LES in general outperforms RANS even at coarse resolution except very near the wall, RANS constraints are limited to th...

In this paper, we study the distribution of distances in random Apollonian network structures (RANS), a family of graphs which has a one-to-one correspondence with planar ternary trees. Using multivariate generating functions that express all information on distances, and singularity analysis for evaluating the coefficients of these functions, we prove a Rayleigh limit distribution for distance...

Large eddy simulation (LES) is now seen more and more as a viable alternative to current industrial practice, usually based on problem-specific Reynolds-averaged Navier-Stokes (RANS) methods. Access to detailed flow physics is attractive to industry, especially in an environment in which computer modelling is bound to play an ever increasing role. However, the improvement in accuracy and flow d...

[1] In this paper we consider the problem of modeling a turbulent pulsating boundary layer over ripples. We compare the results of two modeling strategies, Wilcox’s k w Reynolds-Averaged Navier-Stokes equations (RANS) and large-eddy simulation (LES) employing the Lagrangian dynamic eddy viscosity model. The geometry and parameters employed are relevant to nearshore oceanic flows, and the result...

Predictive capability of RANS and LES models to calculate incipient cavitation of water in a step nozzle is assessed. The RANS models namely, Realizable k-ɛ, SST k-ω and Reynolds Stress Model did not predict any cavitation, due to the limitation of RANS models to predict the low pressure vortex cores. LES WALE model was able to predict the cavitation by capturing the shear layer instability and...

In large eddy simulations (LES) of wall-bounded flows, the need to resolve energycarrying eddies in the vicinity of the wall leads to a prohibitive cost which prevents its use at very high Reynolds numbers. To overcome this limitation, many attempts have been made in the last two decades to model the unresolved scales near the wall. These works mainly focused on two different approaches: hybrid...

This paper is concerned with the numerical simulation of gas flow inside spray dryers, which is known to be highly transient. Experimental evidence presented in the literature to date is acquired either at a scale much smaller than industrial or at a limited number of locations in the system (e.g. the central axis). Alternatively, computational fluid dynamics (CFD) simulation, in particular met...