scholarly journals Motion of the vitreous humour in a deforming eye–fluid-structure interaction between a nonlinear elastic solid and viscoleastic fluid

2018 ◽  
Vol 335 ◽  
pp. 50-64 ◽  
Author(s):  
Karel Tůma ◽  
Judith Stein ◽  
Vít Průša ◽  
Elfriede Friedmann
Author(s):  
Jize Zhong ◽  
Zili Xu

A reduced mesh movement method based on pseudo elastic solid is developed and applied in fluid–structure interaction problems in this paper. The flow mesh domain is assumed to be a pseudo elastic solid. The vibration equation for the structure and the pseudo elastic solid together is derived by applying the displacement continuity condition on the fluid–structure interface. Considering that the actual fluid–structure coupled vibration for structures often appears to be associated with low-order modes, the nodal displacements for the structure and the flow mesh can be computed using the modal superposition of a few low-order modes. Coupled fluid–structure computations are performed for flutter problems of a beam and wing 445.6 using the present method. The calculated results are consistent with the data reported in other references. The computing time is reduced by 65.5% for the beam flutter and 54.8% for the wing flutter compared with the pre-existing elastic solid method.


Author(s):  
A. Castorrini ◽  
V. F. Barnabei ◽  
A. Corsini ◽  
F. Rispoli

Abstract Additive manufacturing represents a new frontier in the design and production of rotor machines. This technology drives the engineering research framework to new possibilities of design and testing of new prototypes, reducing costs and time. On the other hand, the fast additive manufacturing implies the use of plastic and light materials (as PLA or ABS), often including a certain level of anisotropy due to the layered deposition. These two aspects are critical, because the aero-elastic coupling and flow induced vibrations are not negligible for high aspect ratio rotors. In this work, we investigate the aeroelastic response of a small sample fan blade, printed using PLA material. Scope of the work is to study both the structure and flow field dynamics, where strong coupling is considered on the simulation. We test the blade in two operating points, to see the aero-mechanical dynamics of the system in stall and normal operating condition. The computational fluid-structure interaction (FSI) technique is applied to simulate the coupled dynamics. The FSI solver is developed on the base of the finite element stabilized formulations proposed by Tezduyar et al. We use the ALE formulation of RBVMS-SUPS equations for the aerodynamics, the non-linear elasticity is solved with the Updated Lagrangian formulation of the equations of motion for the elastic solid. The strong coupling is made with a block-iterative algorithm, including the Jacobian based stiffness method for the mesh motion.


On the basis of a variational principle, a mixed finite element approach is developed to describe the linear dynamics of coupled fluid–structure interactions. The variables of acceleration in the elastic solid and pressure in the fluid are adopted as the arguments of the variational principle. These are chosen since they directly relate to many practical fluid–structure interaction dynamic problems involving free surface disturbances, e. g. a dam-water system, a fuel cell in an aircraft, etc. Matrix equations describing the motions are presented and four methods of solution discussed, each simplifying and approximating the matrix equations for easier application to solve various types of engineering problems. This is demonstrated by analysing a selection of fluid–structure interaction problems of practical interest. The examples illustrate the general principle and application of the described functional approach without need to resort to more complex dynamic problems which can be analysed in a similar manner.


2016 ◽  
Vol 21 (1) ◽  
pp. 182-210
Author(s):  
Asim Timalsina ◽  
Gene Hou ◽  
Jin Wang

AbstractIn this paper, we propose a new partitioned approach to compute fluid-structure interaction (FSI) by extending the original direct-forcing technique and integrating it with the immersed boundary method. The fluid and structural equations are calculated separately via their respective disciplinary algorithms, with the fluid motion solved by the immersed boundary method on a uniform Cartesian mesh and the structural motion solved by a finite element method, and their solution data only communicate at the fluid-structure interface. This computational framework is capable of handling FSI problems with sophisticated structures described by detailed constitutive laws. The proposed methods are thoroughly tested through numerical simulations involving viscous fluid flow interacting with rigid, elastic solid, and elastic thin-walled structures.


Sign in / Sign up

Export Citation Format

Share Document