Tech Briefs




Steered Adaptive Meshing Applications

Our recent emphasis in fluid-structure interaction analysis has been on the automation of the FSI procedures by the use of steered adaptive meshing (SAM). In this Brief, we present three applications in which SAM was used.

In the first analysis, a gear pump was solved, see Figure 1. The pump was modeled and analyzed in two dimensions. The fluid flow is driven by the two rotating gears, and the fluid mesh needs to be regenerated from time to time. In this analysis, remeshing was automatically performed many times per cycle. The movie above shows the velocity vector plot.






Figure 1  Schematic of gear pump taken from the ADINA User Interface
(shown is also the tiny gap between the gear teeth and the casing)


In the second analysis, a flow meter device was modeled in 3D. In this application, a solid ball is pushed by the fluid and travels along an annular channel. For the finite element model to have valid fluid elements during the analysis, the fluid mesh has to be regenerated while the ball is moving. Figure 2 shows the model geometry, and the velocity and pressure plots are shown in the movie.





Figure 2  Schematic of flow meter







In the third analysis, a pulse damper was modeled in 3D, see Figure 3. In this type of application, an incoming flow fluctuation is dampened and smoothed to prevent large pressure jumps, thereby protecting the pipe system. The flexible structure boundary and hence also the fluid domain in the damper deform due to the incoming pressure pulsation. During the computation, even though the fluid elements are valid all the time, the mesh was regenerated in some time steps to maintain the desired element size.





Figure 3  Schematic of pulse damper







The steered adaptive meshing capability is a powerful tool in ADINA for modeling FSI applications with large deformations. Running automatically, the scheme makes these analyses easy and convenient for the user of the program.


Keywords:
Fluid-structure interaction, FSI, adaptive meshing, steered meshing, error control, gear pump, flow meter, pulse damper