One- and two-equation turbulence models for the prediction of complex cascade flows using unstructured grids

Koubogiannis, DG; Athanasiadis, AN; Giannakoglou, KC

dc.contributor.author	Koubogiannis, DG	en
dc.contributor.author	Athanasiadis, AN	en
dc.contributor.author	Giannakoglou, KC	en
dc.date.accessioned	2014-03-01T01:51:55Z
dc.date.available	2014-03-01T01:51:55Z
dc.date.issued	2002	en
dc.identifier.issn	00457930	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/26508
dc.subject	Compressor cascade flows	en
dc.subject	Laminar separation bubble	en
dc.subject	Low-Reynolds eddy-viscosity models	en
dc.subject	Turbulent production	en
dc.subject	Unstructured grids	en
dc.subject.other	Aspect ratio	en
dc.subject.other	Bubbles (in fluids)	en
dc.subject.other	Chemical modification	en
dc.subject.other	Kinetic energy	en
dc.subject.other	Laminar flow	en
dc.subject.other	Mathematical models	en
dc.subject.other	Navier Stokes equations	en
dc.subject.other	Reynolds number	en
dc.subject.other	Turbulence	en
dc.subject.other	Viscosity	en
dc.subject.other	Turbulence models	en
dc.subject.other	Flow patterns	en
dc.subject.other	cascade	en
dc.subject.other	flow separation	en
dc.subject.other	laminar flow	en
dc.subject.other	Reynolds number	en
dc.subject.other	turbulence	en
dc.title	One- and two-equation turbulence models for the prediction of complex cascade flows using unstructured grids	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0045-7930(01)00086-X	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0045-7930(01)00086-X	en
heal.publicationDate	2002	en
heal.abstract	One- and two-equation, low-Reynolds eddy-viscosity turbulence models are employed in the context of a primitive variable, finite volume, Navier-Stokes solver for unstructured grids. Through the study of the complex flow in a controlled-diffusion compressor cascade at off-design conditions, the ability of the models under consideration to predict the laminar separation bubble close to the leading edge and the boundary layer development is investigated. In order to control the unphysical growth of turbulent kinetic energy near the leading edge stagnation point, appropriate modifications to the conventional models are employed and tested. All of them improve the leading edge flow patterns and significantly affect the size of the predicted laminar separation bubble. The use of an adequately refined mesh around the airfoil, that is formed by triangles placed in a quasi-structured way, allows for the generation of grid elements of moderate aspect ratios. This helps to readily overcome any relevant problems of accuracy; a second-order upwind scheme without flux limiters or least squares approximations is successfully employed for the gradients. The test case includes quasi-3D effects by considering the streamtube thickness variation in the governing equations. © 2002 Elsevier Science Ltd. All rights reserved.	en
heal.journalName	Computers and Fluids	en
dc.identifier.doi	10.1016/S0045-7930(01)00086-X	en
dc.identifier.volume	32	en
dc.identifier.issue	3	en
dc.identifier.spage	403	en
dc.identifier.epage	430	en