Both RaNS (Reynolds-averaged Navier-Stokes) and DES (Detached Eddy Simulation) type turbulence models were used in conjunction with a two-fluid model of bubbly flow and a new subgrid air entrainment model to predict air entrainment and transport in a hydraulic jump. It was found that the void fraction profiles predicted by both methods are in agreement with the experimental data in the lower sh...

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...

in this study prediction of the steady-state flow of branched polymer melts in pipe geometry with finite volume method is presented. our analysis in this study revealed that;for normal-stress tqq , the xpp model can predict this tensor unlike the other viscoelastic models such as ptt or gieskus which can not predict tqq for viscoelastic fluid in two dimensional pipe flows. the fluid is modelled...

A consistent dual-mesh hybrid LES/RANS framework for turbulence modeling has been proposed recently (H. Xiao, P. Jenny, A consistent dual-mesh framework for hybrid LES/RANS modeling, J. Comput. Phys. 231 (4) (2012)). To better enforce componentwise Reynolds stress consistency between the LES and the RANS simulations, in the present work the original hybrid framework is modified to better exploi...

the rheological properties of four different kuwaiti crude oils in the presence of polyacrylamide (paa) were investigated. paa was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. four different temperatures (25, 30, 35, and 40 °c) were used to evaluate different viscoelastic parameters of the treated and untreated kuw...

In this study prediction of the steady-state flow of branched polymer melts in pipe geometry with finite volume method is presented. Our analysis in this study revealed that;for normal-stress tqq , the XPP model can predict this tensor unlike the other viscoelastic models such as PTT or Gieskus which can not predict tqq...

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...

The use of RANS models in the analysis of the urban climate and in air quality studies has become increasingly popular when predictions have to deal with complex flows, such as those arising at the street-scale. The need for model assessment and validation has thus also become crucial towards establishing the reliability of RANS simulations of heat and mass transport in urban areas. In this res...