MODULES

Three-Dimensional Collapse Of Water Column With Obstacle

Problem Definition:

A water column is allowed to collapse against an obstacle [3] inside an enclosure. Problem setup is shown in Fig. 3.1. The computational domain is of size 3.22 × 1 × 1 which is discretized into non-uniform 471000 hexahedral cells. All the boundaries are treated as no-slip walls except for the top one, which is open to atmosphere. Initially, a water column is maintained at a height of 0.55 m on the right side of the domain, and then suddenly it is allowed to flow and strike the obstacle and the other end of the enclosure.




Figure 3.1: Schematic diagram for 3-dimensional collapse of water column against an obstacle. (units: mm)



Results:

Simulations are carried out for 6 seconds and the snapshots of the water front are shown in Fig. 3.2 after time 1.2 and 2 seconds. In the beginning, until the water front hits the other end of the enclosure, then the water front hits the wall and returns back (time t=2.0 sec) as shown in experimental and numerical results reported in the literature [2, 3]. Water column height at three different locations has also been plotted and is compared with the published results as shown in Fig. 3.3..



(a)



(b)

Figure 3.2: Temporal evolution of 3-dimensional water column collapsing against an obstacle after time t = 1.2 and 2.0. (a) Experimental results by Klostermann et al. [1](b) numerical simulation by Gao et al. [2]



Figure 3.3: Comparison of water column height with the published literature using balanced & consistent algorithm at locations (a) H1, (b) H2 and (c) H3 .

References:

[1] Klostermann J., Schaake K., and Schwarze R. (2012) ‘Numerical simulation of a single rising bubble by vof with surface compression’, Int. J. Numer. Meth. Fluids, vol. 71, pp. 960–982.

[2] Gao Z., Vassalos D., and Gao Q. (2010) ‘Numerical simulation of water flooding into a damaged vessels compartment by the volume of fluid method.’, Ocean Engineering, vol. 37, p. 14281442.

[3] Kleefsman K., Fekken G., Veldman A., Iwanowski B., and Buchner B. (2005) ‘A volume-of-fluid based simulation method for wave impact problems.’, Journal of Computational Physics, vol. 206, p. 363393.