Transition and heat transfer predictions in a turbine cascade at various free-stream turbulence intensities through a one-equation turbulence model

Tsourakis, GI; Koubogiannis, DG; Giannakoglou, KC

dc.contributor.author	Tsourakis, GI	en
dc.contributor.author	Koubogiannis, DG	en
dc.contributor.author	Giannakoglou, KC	en
dc.date.accessioned	2014-03-01T01:18:27Z
dc.date.available	2014-03-01T01:18:27Z
dc.date.issued	2002	en
dc.identifier.issn	0271-2091	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15018
dc.subject	Free-stream induced viscosity	en
dc.subject	Heat transfer	en
dc.subject	Spalart-Allmaras turbulence model	en
dc.subject	Transition	en
dc.subject	Turbine flows	en
dc.subject	Unstructured grids	en
dc.subject.classification	Computer Science, Interdisciplinary Applications	en
dc.subject.classification	Mathematics, Interdisciplinary Applications	en
dc.subject.classification	Mechanics	en
dc.subject.classification	Physics, Fluids & Plasmas	en
dc.subject.other	Boundary layer flow	en
dc.subject.other	Heat transfer	en
dc.subject.other	High pressure turbomachinery	en
dc.subject.other	Mathematical models	en
dc.subject.other	Nozzles	en
dc.subject.other	Reynolds number	en
dc.subject.other	Viscosity	en
dc.subject.other	Free-stream turbulence	en
dc.subject.other	Turbulent flow	en
dc.subject.other	cascade	en
dc.subject.other	flow modeling	en
dc.subject.other	heat transfer	en
dc.subject.other	turbine	en
dc.subject.other	turbulence	en
dc.subject.other	viscosity	en
dc.title	Transition and heat transfer predictions in a turbine cascade at various free-stream turbulence intensities through a one-equation turbulence model	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/fld.262	en
heal.identifier.secondary	http://dx.doi.org/10.1002/fld.262	en
heal.language	English	en
heal.publicationDate	2002	en
heal.abstract	The one-equation Spalart-Allmaras turbulence model, coupled with criteria for the prediction of the transition onset, is employed for the numerical prediction of the heat transfer along the nozzle guide vanes of a high-pressure turbine, at various operating conditions. Emphasis is put on how to overcome a known shortcoming of the Spalart-Allmaras model, i.e. its insensitivity to free-stream turbulence. For this purpose, an extra viscosity coefficient is defined and used in the mean flow equations. This extra viscosity is proportional to the free-stream turbulence with a damping in the boundary layer. Its use is adequate to circumvent the aforementioned weakness of the Spalart-Allmaras model, without any other intervention in the model itself. For the prediction of the onset of transition, the Abu-Ghannam and Shaw and the Mayle criteria are used, depending on the level of free-stream turbulence. Both yield very satisfactory predictions in a wide range of Reynolds numbers and/or turbulence intensities. From a numerical point of view, this paper proposes techniques for the implementation of the solution method on unstructured grids with triangular elements and reconfirms findings of previous works, like the suitability of the containment-circle tessellation in highly stretched grids. Copyright © 2002 John Wiley and Sons, Ltd.	en
heal.publisher	JOHN WILEY & SONS LTD	en
heal.journalName	International Journal for Numerical Methods in Fluids	en
dc.identifier.doi	10.1002/fld.262	en
dc.identifier.isi	ISI:000174836500005	en
dc.identifier.volume	38	en
dc.identifier.issue	11	en
dc.identifier.spage	1091	en
dc.identifier.epage	1110	en