Strongly Coupled Partitioned Fluid Structure Interaction

Strongly Coupled Partitioned Fluid Structure Interaction: Robustness Analysis of Interface Quasi Newton Temporal Coupling Framework

Sripathy, Kiran (TU Delft Aerospace Engineering)

van Zuijlen, A.H. (mentor)

Delft University of Technology

Aerospace Engineering

2021-01-27

Commercial FSI solvers employ partitioned FSI, wherein CFD and CSM solvers are used sequentially to resolve the coupling of interface displacement and stress/force. For strongly coupled problems, multiple sub-iterations of both the solvers are required for a stable and accurate solution. IQN-ILS framework requires fewer sub-iterations for resolving partitioned coupling, which is employed on a FSI benchmark case “Cylinder with trailing flap” to evaluate its robustness. Forces computed on the flap are plagued with numerical noise. Various strategies ranging from altering displacement tolerance to relative number of degrees of freedom on the interface were attempted to dampen noise. Despite these noise prevention strategies, the force data from IQN-ILS framework is still noisier in comparison to fixed-point iteration. A stopgap fix involving the smoothing of displacements at flap interface using Smoothing spline, Savitzky Golay, Sinusoidal curve fitting filters was implemented. Results from Smoothing spline and Savitzky Golay filters are promising.

FSI
Partitioned
Coupling
Quasi Newton
Least squares fitting methods
Robustness Evaluations

http://resolver.tudelft.nl/uuid:c3a197df-02e0-48e0-884a-05e7f4f4bddc

Student theses

master thesis

© 2021 Kiran Sripathy