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 ...

in this paper, a two-dimensional reynolds averaged navier-stokes (rans) model is developed to simulate the shoaling, breaking and overtopping of a solitary wave over a vertical breakwater. turbulence intensity is described by using a k turbulence closure model and the free surface configuration is tracked by volume of fluid (vof) technique. to validate the numerical model the simulation result...

The seminar discusses basic concepts of turbulence modeling in computational fluid dynamics (CFD). There are two mainstreams present in the field of interest. The first one are so called Reynolds averaged Navier-Stokes (RANS) models. RANS models are most widely used nowadays. Therefore theoretical aspects of RANS models are presented in more detail. The second mainstream presents direct numeric...

[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...

Random Apollonian networks have been recently introduced for representing real graphs. In this paper we study a modified version: random Apollonian network structures (RANS), which preserve the interesting properties of real graphs and can be handled with powerful tools of random generation. We exhibit a bijection between RANS and ternary trees, that transforms the degree of nodes in a RANS int...

This paper presents computational results for two DES (Detached Eddy Simulation), one hybrid RANS (Reynolds Averaged Navier-Stokes)/ LES (Large Eddy Simulation) and some preliminary results from PANS (Partially Averaged Navier-Stokes) turbulence for simulation of unsteady separated turbulent flows. The models are implemented in a full 3-D Navier Stokes solver and are based on the twoequation k-...

The complex flow physics challenges and asks questions regarding these challenges a wide range of jet flows found in aerospace engineering. Hence, the daunting task facing Reynolds-averaged Navier-Stokes (RANS) technology, for which the time average of the turbulent flow field is solved, is set out. Despite the clear potential of large eddy simulation (LES)-related methods and hybrid forms invo...

wall displacements and ground pressure acting on the lining of a tunnel increase with time. these time-dependent deformations are both due to face advance effect and to the time-dependent behavior of the rock mass.  viscoelastic materials exhibit both viscous and elastic behaviors. thorough this study, the effect of different linear viscoelastic models including maxwell, kelvin and kelvin-voigt...

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...