SPH Modeling of Fluid-Structure Interaction

The sequence of results (ordered left to right and top to bottom) shows an SPH simulation of a tethered fish flapping in a stream with a Reynolds number of 1,000. An inextensible rope is connected to the left boundary. The color presents velocity magnitude of the fish body and vorticity in flow.

Motivation and Objectives

Fluid-structure interaction (FSI) can be found in many natural phenomena, such as birds flying and fish swimming. Meanwhile, it also plays a very important role in a wide range of engineering areas, e.g. aeronautical engineering, coastal engineering and biomedical engineering. The essential of FSI is the interaction between movable or deformable structures with internal or surrounding fluid flows.

Approach to Solution

We propose a numerical modeling of FSI (fluid-structure interaction) problems in a unified SPH (smoothed particle hydrodynamics) framework. Rather than being strictly monolithic, the present modeling is the combination of a conventional SPH formulation for fluid motions and a total Lagrangian SPH formulation dealing with the structure dynamics. Since both fluid and solid governing equations are still solved with SPH algorithms, fluid-structure coupling is straightforward and the momentum conservation of an FSI system is strictly satisfied. Furthermore, the application of a Lagrangian kernel eliminates the particle-distribution artifact which exhibits in previous SPH simulation of structure dynamics using the incremental constitutive model. Several tests including pure structure oscillation and FSI benchmark cases have been carried out to validate the present modeling and demonstrate its potential.

Key Results

  • SPH modeling of fluid-structure interaction, C. Zhang, X. Y. Hu. Journal of Hydrodynamics, Vol. 30 (2018), pp. 62-69
  • Liquid Splash Modeling with Neural Networks. K. Um, X. Y. Hu, N. Thuerey. ACM SIGGRAPH/Eurographics Symposium on Computer Animation 2018, Computer Graphics Forum, Vol. 37, Issue 8
  • An incremental-stencil WENO reconstruction for simulation of compressible two-phase flows. B. Wang, G. Xiang, X.Y. Hu. International Journal of Multiphase Flow, Vol. 104 (2018), pp. 20-31