Engineering continues to evolve continuously, improving the way analysis and calculations used to be carried out to start projects. Today, applications, systems, computer models, etc. are used, ensuring greater efficiency in processes.
The simulations themselves have undergone several optimizations over time, keeping up with the latest technologies, including the multiphysics branch. FSI - Fluid-Structure Interaction - is a term that recurs in discussions on this subject.
The following will discuss what FSI analysis is and how it is applied in industry.
What is FSI analysis?
In various industrial scenarios, it is possible to observe interactions between a rigid structure and a fluid in flow. The analysis of fluid-structure interaction consists of associating the laws governing fluid dynamics with the mechanics involving structures.
To carry out an FSI analysis, it is necessary to master the principles and techniques used in analysis using the finite element method (FEM) and computational fluid dynamics (CFD).
Check out some of the texts on the Kot Blog on these topics in the links below:
- For laypeople: understanding the Finite Element Method
- Understanding the Finite Element Method (FEM)
- FEA versus FEM: What is the correct term?
- Computational Fluid Dynamics: the physics and mathematics involved in CFD analysis
- CFD simulation: learn about the main uses in industry
- Finite element methods, finite volumes and discrete elements: what are the differences?
In short, these interactions can be observed from two points of view: the behavior of the fluid after encountering the structure or the behavior of the structure under the action of the fluid flow.
Considering Fluid-Structure Interaction in design and modeling
Fluid can be defined as a substance that deforms continuously when subjected to a shearing force, regardless of the magnitude of that force. [2]
Bulk materials with high humidity levels can behave similarly to fluids, as in one of Kot's success stories. In the study in question, an FSI analysis was carried out on a very wet granular material stored in a silo. Under the conditions evaluated, the material accumulates on the walls of the asset up to a point where the mass detaches and flows downwards, forming an avalanche.
This avalanche advances towards the extraction feeder, which is not dimensioned for this feeding condition, and suffers severe impacts, enough to collapse its metal structure. The simulation shown in Video 1 shows the analysis event.
Video 1: FSI analysis of a silo avalanche. [3]
In other processes, there are industrial mixers, which have moving parts and are considered essentially rigid parts that agitate a fluid, responsible, for example, for incorporating particulates into liquids. In this context, mixing efficiency is the most important quantity to be computed.
On the other hand, it is also possible to calculate the stresses in the agitators. Solid structures can be treated as completely stationary obstructions in the fluid flow, in order to compute the stresses in solid materials.
FSI analysis and its applications in industry
In various industrial scenarios, the flow of fluids, such as air and water, can result in great stresses and strains in structures. These, in turn, can cause vibrations and critical deformations in rigid bodies.
FSI analysis can be carried out on various industrial assets. Some of the possible applications are:
- Analysis of the effects generated by vortices in submerged structures, such as dam gates, pipes, etc..;
- Analysis of aerospace components;
- Analysis of components in the naval industry;
- Analysis of automotive components;
- Components of agitation systems such as reactors, mixers, thickeners, etc;
Conclusion
FSI analyses have wide applicability in the industrial context, with results that enable a physical-mathematical understanding of effects that are not visible to the naked eye. As an example, it is possible to list the sizing of the components of an agitation system compatible with the required efforts generated by the movement of the fluid or the sizing of a structure capable of resisting the impact of a fluid in flow.
In this way, it becomes possible to design structures with greater slenderness and lower costs, increase process efficiency (agitation efficiency), measure the estimated useful life of assets under the operating conditions in which it is inserted, among other things.
A Kot possui ampla experiência na área e pode auxiliar em seu negócio. Consulte nossa equipe para avaliar as possibilidades de aplicação em seu contexto.
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References:
[1] https://br.comsol.com/multiphysics/fluid-structure-interaction
[2] STREETER, V. L. Fluid Mechanics. 1951.
[3] Acervo Kot Engenharia.
