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Efficient approaches for fluid structure interaction with fully enclosed incompressible flow domainsKüttler, U. (author), Förster, C. (author), Wall, W.A. (author)Many popular partitioned approaches to fluid-structure interaction (FSI) problems fail to work for an interesting subset of problems if highly deformable structures are interacting with incompressible flows. This is particularly true for coupling approaches based on Dirichlet-Neumann substructuring, both for weak and strong coupling schemes. The...conference paper 2006
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Wackers, J. (author), Koren, B. (author)A surface capturing method is developed for steady water-air flow with gravity. Second-order accuracy is obtained with flux limiting and turbulence is modeled with Menter's model. The model is solved efficiently with a combination of multigrid and defect correction. Results for two test cases confirm the efficiency and accuracy of the method.conference paper 2006
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Elsenaar, B. (author)Vortices behind aircraft are inherently related to the generation of lift and decay very slowly. When strong, they present a safety problem for the following aircraft and for that reason specific separation distances are recommended by ICAO (the International Civil Airline Organisation). At the same time, they limit the number of aircraft that...conference paper 2006
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Sasaki, D. (author), Dhanesekaran, C. (author), Dawes, B. (author), Shahpar, S. (author)Automatic robust unstructured hybrid meshing is indispensable for the success in design optimisation. In addition, it is important to maintain the mesh quality for deformation of geometry throughout the optimisation process for the reliability of optimal design. Mesh adaptation is useful to capture the flow feature which can highly affect flow...conference paper 2006
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Desideri, J.A. (author), Dervieux, A. (author)This lecture is devoted to the presentation of two particular "hierarchical" approaches to numerical shape optimization in aerodynamics design: 1) multilevel parametric shape optimization algorithms; 2) additive preconditioners. The first approach is inspired from the classical geometrical multigrid method, except that here the geometrical...conference paper 2006
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Papadimitriou, D.I. (author), Giannakoglou, K.C. (author)This paper summarizes progress, recently made in the Lab. of Thermal Turbomachines of NTUA, on the formulation and use of the continuous adjoint methods in aerodynamic shape optimization problems. The basic features of state of the art adjoint methods and tools which are capable of handling arbitrary objective functions, cast in the form of...conference paper 2006
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Okkels, F. (author), Bruus, H. (author)We address the design of optimal reactors for supporting biological cultures using the method of topology optimization. For some years this method have been used to design various optimal microfluidic devices [1, 2, 3, 4]. We apply this method to distribute optimally biologic cultures within a flow of nutrition. From this optimized distribution...conference paper 2006
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Bauer, J. (author), Bykov, V. (author), Maas, U. (author)The usage of detailed chemical kinetics for the mathematical modeling of combustion processes is desirable, but leads to a high computational effort. In the present work one of the methods of simplification of chemical kinetics - Intrinsic low-dimensional manifolds (ILDMs) is considered. Whereas in most CFD applications ILDMs are calculated in...conference paper 2006
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Pal, M. (author), Edwards, M.G. (author): A family of flux-continuous, locally conservative, finite-volume schemes has been developed for solving the general tensor pressure equation of petroleum reservoir-simulation on structured and unstructured grids. These schemes are control-volume distributed. The schemes are applicable to diagonal and full tensor pressure equation with...conference paper 2006
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Tang, J.H. (author), Jiang, B. (author)A numerical calculation procedure based on the least-squares finite element method (LSFEM) is employed to study the fluid flow and heat transfer in a 3-D heat exchangers with in-lined and staggered multiple-row (4 rows) tubes. In this study, the fin pitch of the heat exchanger is 8 fins per inch and the fluid flow is assumed steady,...conference paper 2006
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Meeks, E. (author), Chou, C.P. (author)In the past decade, the computational fluid dynamics (CFD) community has put increasing attention on incorporating complex chemistry and physics into CFD simulations. However, for many practicing engineers today there is still much lacking in the effectiveness of reacting-flow simulation. Particularly in the area of combustion, the results can...conference paper 2006
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Murea, C.M. (author), Vazquez, C. (author)We study the fluid-structure coupled problem between an incompressible fluid and an elastic curved arch. The fluid flow is modeled by 2-D steady Stokes equations with normal velocity boundary condition on the curved interface and the arch verifies a particular 1-D case of the thin shell theory of Koiter. We present an optimal control formulation...conference paper 2006
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Eca, L. (author), Hoekstra, M. (author)This paper presents an exercise of Code Verification with two manufactured solutions valid for 2D RANS equations supplemented either with the one-equation Spalart & Allmaras or with the two-equation BSL k-w turbulence model. When the manufactured solution is applied with the eddy viscosity frozen, second order convergence behaviour is shown....conference paper 2006
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Bohbot, J. (author), Gillet, N. (author)This paper highlights the impact of different mesh remapping techniques on staggered grids in the context of combustion simulations in particular for direct injection Diesel engines. A remapping method based on a least squares method is used on the staggered grid to interpolate non-conservative variables like pressure and temperature. Then the...conference paper 2006
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Koutlas, G.N. (author)The purpose of the present study is to explore and validate the efficiency and accuracy of the predictive capability of CFD models for fully developed natural fires in large compartments. The FDS CFD software was used to simulate three large-scale fire tests. The fire tests (nine in total) had been carried out in 1993 at Cardington UK, in...conference paper 2006
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Winckelmans, G. (author), Cocle, R. (author), Dufresne, L. (author), Capart, R. (author), Bricteux, L. (author), Daeninck, G. (author), Lonfils, T. (author), Duponcheel, M. (author), Desenfans, O. (author), Georges, L. (author)This paper aims at presenting DNS and LES as applied to the simulation of vortex wakes: in laboratory conditions (moderate to medium Reynolds numbers) and up to real aircraft conditions (high to very high Reynolds numbers). Only incompressible flows are considered. DNS and LES are able to capture complex 3-D physics provided one uses high...conference paper 2006
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Suiker, A.S.J. (author), Turteltaub, S. (author)A recently developed thermo-mechanical model [1] is presented that can be used to simulate the interactions between martensitic phase transformations and crystalline damage growth at the austenitic grain level. Subgrain information is included in the model via the crystallographic theory of martensitic transformations, see also [2,3]. The state...conference paper 2006
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Soulard, O. (author), Sabel'nikov, V. (author)In the field of turbulent combustion, Lagrangian Monte Carlo (LMC) methods (Pope, 85) have become an essential component of the probability density function (PDF) approach. LMC methods are based on stochastic particles, which evolve from prescribed stochastic ordinary differential equations (SODEs). They are used to compute the one-point...conference paper 2006
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Braza, M. (author), El Akoury, R. (author), Martinat, G. (author), Hoarau, Y. (author), Harran, G. (author), Chassaing, P. (author)This paper analyses the performances of adapted URANS and DES turbulence^modelling for high-Reynolds 2D and 3D aerodynamic flows with a pronounced periodic character. The flow configurations is the NACA0012 airfoil in pitch (experimental test-case by Mc Croskey & Mc Alistair, 1976) at Reynolds number 0.98x10^6, as well as the inherently unsteady...conference paper 2006
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Möller, M. (author), Kuzmin, D. (author)Gradient recovery techniques for the design of a posteriori error indicators are reviewed in the context of fluid dynamic problems featuring shocks and discontinuities. An edgewise slope limiting approach tailored to linear finite element discretizations is presented. The improved gradient values at edge midpoints are recovered as the limited...conference paper 2006