Flow over a flexible cable

(movie)

This is an animation of flow over a flexible cable. The surface shown is an iso-surface of spanwise vorticity (magnitude = -0.2). The flow is going from upper-left to lower-right (in the x-direction). The displacement of the cable in the cross-flow direction is indicated by the shape of the leading edge of the iso-surface (upper-left). The cable is responding in a standing wave pattern with an amplitude of 0.7 cable diameters in the cross-flow direction. There are (standing wave) nodes at the start, middle and end of the cable shown, and the solution is periodic in the spanwise direction. Note the complex pattern of vorticity (compared to that from a fixed cylinder).

(movie)

This another view of the same animation of flow over a flexible cable. The slices show contour levels of spanwise vorticity (red is positive and blue is negative). The flow is going from upper-left to lower-right (in the x-direction). The cable is responding in a standing wave pattern with an amplitude of 0.7 cable diameters in the cross-flow direction. The slices are positioned at the cable nodes (1st, 3rd and 5th slice) and anti-nodes (2nd and 4th slice). Note the difference in the wake behind the node compared to the anti-node.

This simulation was run with the following physical parameters:

The computations were performed on an Intel Paragon using a Spectral-Element/Fourier code. Approximately 225,000 mesh points were used in the computation. Computation time on 16 processors was approximately 5 seconds per time step, or 4 hours per shedding cycle (one period of the movie). Over 300 MBytes of data were generated to produce the animation. If you are interested in finding more about the simulation, please contact Dave Newman (djnewman@cfm.brown.edu).