Continuous adjoint approach to the Spalart-Allmaras turbulence model for incompressible flows

Zymaris, AS; Papadimitriou, DI; Giannakoglou, KC; Othmer, C

dc.contributor.author	Zymaris, AS	en
dc.contributor.author	Papadimitriou, DI	en
dc.contributor.author	Giannakoglou, KC	en
dc.contributor.author	Othmer, C	en
dc.date.accessioned	2014-03-01T01:30:01Z
dc.date.available	2014-03-01T01:30:01Z
dc.date.issued	2009	en
dc.identifier.issn	0045-7930	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19458
dc.subject	Adjoint Method	en
dc.subject	Boundary Condition	en
dc.subject	Differential Equation	en
dc.subject	Incompressible Flow	en
dc.subject	Integral Functional	en
dc.subject	Loss Function	en
dc.subject	Reference Value	en
dc.subject	Reynolds Number	en
dc.subject	Turbulence Model	en
dc.subject	spalart allmaras	en
dc.subject.classification	Computer Science, Interdisciplinary Applications	en
dc.subject.classification	Mechanics	en
dc.subject.other	DISCRETE ADJOINT	en
dc.subject.other	UNSTRUCTURED GRIDS	en
dc.subject.other	DESIGN	en
dc.subject.other	OPTIMIZATION	en
dc.subject.other	FORMULATION	en
dc.title	Continuous adjoint approach to the Spalart-Allmaras turbulence model for incompressible flows	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.compfluid.2008.12.006	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.compfluid.2008.12.006	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	A continuous adjoint formulation for the computation of the sensitivities of integral functions used in steady-flow, incompressible aerodynamics is presented. Unlike earlier continuous adjoint methods, this paper computes the adjoint to both the mean-flow and turbulence equations by overcoming the frequently made assumption that the variation in turbulent viscosity can be neglected. The development is based on the Spalart-Allmaras turbulence model, using the adjoint to the corresponding differential equation and boundary conditions. The proposed formulation is general and can be used with any other integral function. Here, the continuous adjoint method yielding the sensitivities of the total pressure loss functional for duct flows with respect to the normal displacements of the solid wall nodes is presented. Using three duct flow problems, it is demonstrated that the adjoint to the turbulence equations should be taken into account to compute the sensitivity derivatives of this functional with high accuracy. The so-computed derivatives almost coincide with "reference" sensitivities resulting from the computationally expensive direct differentiation. This is not, however, the case of the sensitivities computed without solving the turbulence adjoint equation, which deviates from the reference values. The role of all newly appearing terms in the adjoint equations, their boundary conditions and the gradient expression is investigated, significant and insignificant terms are identified and a study on the Reynolds number effect is included. (C) 2008 Elsevier Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	COMPUTERS & FLUIDS	en
dc.identifier.doi	10.1016/j.compfluid.2008.12.006	en
dc.identifier.isi	ISI:000267201100004	en
dc.identifier.volume	38	en
dc.identifier.issue	8	en
dc.identifier.spage	1528	en
dc.identifier.epage	1538	en