Dynamics and Stability of Spaghetti and Reverse Spaghetti Problems Coupled with Fluid Force

The dynamic behavior of a flexible beam that is pulled into and drawn out of a gap in an elastic wall with a constant velocity is presented using a mechanical model and experiments. We focus particularly on the effects of the guide in front of the inlet of the wall gap and the fluid force on the beam behaviors. The presented model is verified to simulate well the behavior of the beam when the guide is provided in front of the inlet. In the case of the drawing out the beam, we found out that the fluid force works to be the beam destabilized, and the divergence type instability phenomena is caused in the beam due to the fluid force when the driving velocity is high or the density of the fluid is also high through numerical simulations