Show simple item record

contributor authorRoberto Pacciani
contributor authorAtabak Fadai-Ghotbi
contributor authorSylvain Lardeau
contributor authorMichele Marconcini
contributor authorMichael A. Leschziner
date accessioned2017-05-09T00:47:24Z
date available2017-05-09T00:47:24Z
date copyrightJuly, 2011
date issued2011
identifier issn0889-504X
identifier otherJOTUEI-28774#031016_1.pdf
identifier urihttp://yetl.yabesh.ir/yetl/handle/yetl/147802
description abstractA three-equation model has been applied to the prediction of separation-induced transition in high-lift low-Reynolds-number cascade flows. Classical turbulence models fail to predict accurately laminar separation and turbulent reattachment, and usually overpredict the separation length, the main reason for this being the slow rise of the turbulent kinetic energy in the early stage of the separation process. The proposed approach is based on solving an additional transport equation for the so-called laminar kinetic energy, which allows the increase in the nonturbulent fluctuations in the pretransitional and transitional region to be taken into account. The model is derived from that of (2004, “Modelling Bypass Transition With Low-Reynolds-Number Non-Linear Eddy-Viscosity Closure,” Flow, Turbul. Combust., 73, pp. 49–76), which was originally formulated to predict bypass transition for attached flows, subject to a wide range of freestream turbulence intensity. A new production term is proposed, based on the mean shear and a laminar eddy-viscosity concept. After a validation of the model for a flat-plate boundary layer, subjected to an adverse pressure gradient, the T106 and T2 cascades, recently tested at the von Kármán Institute, are selected as test cases to assess the ability of the model to predict the flow around high-lift cascades in conditions representative of those in low-pressure turbines. Good agreement with experimental data, in terms of blade-load distributions, separation onset, reattachment locations, and losses, is found over a wide range of Reynolds-number values.
publisherThe American Society of Mechanical Engineers (ASME)
titleCalculation of High-Lift Cascades in Low Pressure Turbine Conditions Using a Three-Equation Model
typeJournal Paper
journal volume133
journal issue3
journal titleJournal of Turbomachinery
identifier doi10.1115/1.4001237
journal fristpage31016
identifier eissn1528-8900
keywordsPressure
keywordsFlow (Dynamics)
keywordsSeparation (Technology)
keywordsTurbulence
keywordsEddies (Fluid dynamics)
keywordsViscosity
keywordsKinetic energy
keywordsReynolds number
keywordsStress
keywordsShear (Mechanics)
keywordsBubbles
keywordsBoundary layers
keywordsTurbines
keywordsBlades
keywordsEquations
keywordsPressure gradient
keywordsCascades (Fluid dynamics)
keywordsFlat plates AND Modeling
treeJournal of Turbomachinery:;2011:;volume( 133 ):;issue: 003
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record