"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:ee6e171b-e41f-4f34-bb8c-22501be69aae","http://resolver.tudelft.nl/uuid:ee6e171b-e41f-4f34-bb8c-22501be69aae","Added Mass Effects of Compressible and Incompressible Flows in Fluid-Structure Interaction","Van Brummelen, E.H.","","2009","The subiteration method which forms the basic iterative procedure for solving fluid structure-interaction problems is based on a partitioning of the fluid-structure system into a fluidic part and a structural part. In fluid-structure interaction, on short time scales the fluid appears as an added mass to the structural operator, and the stability and convergence properties of the subiteration process depend significantly on the ratio of this apparent added mass to the actual structural mass. In the present paper, we establish that the added-mass effects corresponding to compressible and incompressible flows are fundamentally different. For a model problem, we show that on increasingly small time intervals, the added mass of a compressible flow is proportional to the length of the time interval, whereas the added mass of an incompressible flow approaches a constant. We then consider the implications of this difference in proportionality for the stability and convergence properties of the subiteration process, and for the stability and accuracy of loosely-coupled staggered time-integration methods.","fluid-structure interaction; added-mass effect; compressible and incompressible flow; subiteration","en","report","Delft Aerospace Computational Science","","","","","","","","Aerospace Engineering","Aerospace Materials & Manufacturing","","","",""
"uuid:99a5987a-710f-436e-8d97-9bbcd072a424","http://resolver.tudelft.nl/uuid:99a5987a-710f-436e-8d97-9bbcd072a424","Validation of the interface-GMRES(R) solution method for fluid-structure interactions","Michler, C.; Van Brummelen, E.H.; In 't Groen, R.; De Borst, R.","","2006","The numerical solution of fluid-structure interactions with the customary subiteration method incurs numerous deficiencies. We validate a recently proposed solution method based on the conjugation of subiteration with a Newton-Krylov method, and demonstrate its superiority and beneficial characteristics.","fluid-structure interaction; subiteration; Newton-Krylov method; GMRES; reuse of Krylov vectors","en","conference paper","Delft University of Technology; European Community on Computational Methods in Applied Sciences (ECCOMAS)","","","","","","","","Aerospace Engineering","","","","",""
"uuid:1f81dd41-e613-400c-995b-db225f506b03","http://resolver.tudelft.nl/uuid:1f81dd41-e613-400c-995b-db225f506b03","Validation of the interface-GMRES(R) solution method for fluid-structure interactions","Michler, C.; Van Brummelen, E.H.; In 't Groen, R.; De Borst, R.","","2006","The numerical solution of fluid-structure interactions with the customary subiteration method incurs numerous deficiencies. We validate a recently proposed solution method based on the conjugation of subiteration with a Newton-Krylov method, and demonstrate its superiority and beneficial characteristics.","fluid-structure interaction; subiteration; Newton-Krylov method; GMRES; reuse of Krylov vectors","en","conference paper","","","","","","","","","","","","","",""
"uuid:2eed1d10-3271-4708-948d-cfffcb23c7a5","http://resolver.tudelft.nl/uuid:2eed1d10-3271-4708-948d-cfffcb23c7a5","Space/Time Multigrid for a Fluid-Structure-Interaction Problem","Van Brummelen, E.H.; Van der Zee, K.G.; De Borst, R.","","2006","The basic iterative method for solving fluid-structure-interaction problems is a defect-correction process based on a partitioning of the underlying operator into a fluid part and a structural part. In the present work we establish for a prototypical model problem that this defect-correction process yields an excellent smoother for multigrid, on account of the relative compactness of the fluid part of the operator with respect to the structural part. We show that the defect-correction process in fact represents an asymptotically-perfect smoother, i.e., the effectiveness of the smoother increases as the mesh is refined. Consequently, on sufficiently fine meshes the fluid-structure-interaction problem can be solved to arbitrary accuracy by one iteration of the defect-correction process followed by a coarse-grid correction. Another important property of the defect-correction process is that it smoothens the error in space/time, so that the coarsening in the multigrid method can be applied in both space and time.","fluid-structure interaction; space/time multigrid; relatively-compact partitions; asymptotically-perfect smoothing; subiteration; space/time finite-element methods","en","report","Delft Aerospace Computational Science","","","","","","","","Aerospace Engineering","Aerospace Materials & Manufacturing","","","",""
"uuid:74c60eed-9296-4d72-bd19-0c0005a84c63","http://resolver.tudelft.nl/uuid:74c60eed-9296-4d72-bd19-0c0005a84c63","Efficient Numerical Methods for Fluid-Structure Interaction","Michler, C.","De Borst, R. (promotor)","2005","Numerical solution methods for fluid-structure interaction are of great importance in many engineering disciplines. The computation of fluid-structure interactions is challenging on account of their free-boundary and multi-physics character. The different length and time scale discretization requirements of the fluid and structure subsystems typically translate into the use of non-matching meshes at the fluid-structure interface. Under such an incompatible discretization, maintaining the conservation properties at the fluid-structure interface is in general non-trivial. Moreover, the solution of the coupled fluid-structure equations by the customary subiteration method often lacks robustness and efficiency. These aspects provide the motivation for the research into conservative discretization techniques and efficient iterative solution methods for fluid-structure interaction presented in this thesis. We investigate an approach that enables conservation at the interface even for incompatible fluid and structure discretizations. Numerical results demonstrate the relevance of maintaining conservation at the fluid-structure interface for the stability and accuracy of the numerical solution. To overcome the deficiencies of the subiteration solution method, we propose to combine subiteration with GMRES acceleration. Since the acceleration can be confined to the degrees-of-freedom of the interface, the acceleration itself requires only negligible computational resources. Moreover, the combined method allows for the optional reuse of Krylov vectors in subsequent invocations of GMRES, which can considerably enhance the efficiency of the method. Since the proposed method retains the modularity of the underlying subiteration method, its implementation is straightforward in codes that already use subiteration as a solver. Detailed convergence studies and a comparison with standard subiteration demonstrate the effectiveness of the proposed solution method.","Fluid-structure interaction; partitioning; subiteration; GMRES; Newton-Krylov methods; efficiency; energy conservation; space/time finite-element method","en","doctoral thesis","","","","","","","","","Aerospace Engineering","","","","",""
"uuid:c0105e1c-4e7c-4c80-9322-81fc1bb29962","http://resolver.tudelft.nl/uuid:c0105e1c-4e7c-4c80-9322-81fc1bb29962","Interface-GMRES(R) Acceleration of Subiteration for Fluid-Structure-Interaction Problems","Van Brummelen, E.H.; Michler, C.; De Borst, R.","","2005","Subiteration forms the basic iterative method for solving the aggregated equations in fluid-structure-interaction problems, in which the fluid and structure equations are solved alternately subject to complementary partitions of the interface conditions. However, this subiteration process can be defective or inadequate, as it is endowed with only conditional stability and, moreover, divergence can occur despite formal stability due to nonnormality. Furthermore, the subiteration method generally operates within a sequential time-integration process to solve a sequence of similar problems, but is unable to exploit this property. To overcome these shortcomings, the present work proposes to accelerate the subiteration method by means of a Krylov method, viz., GMRES. We show that the Krylov space can be composed of vectors in a low-dimensional subspace associated with the discrete representation of a function on the fluid-structure interface. The corresponding Interface-GMRES-acceleration procedure requires negligible computational resources, and retains the modularity of the underlying subiteration method. Moreover, the Krylov space can be optionally reused in subsequent invocations of the GMRES method, conforming to the GMRESR procedure. Detailed numerical results for a prototypical model problem are presented to illustrate the effectiveness of the proposed Interface GMRES(R)-acceleration of the subiteration method.","fluid-structure interaction; subiteration; GMRES; GMRESR; monolithic methods; convergence and stability","en","report","Delft Aerospace Computational Science","","","","","","","","Aerospace Engineering","Aerospace Materials & Manufacturing","","","",""