MODULES

Collapse Of Water Column

Problem Definition:

This test case is also referred as the Dam break problem. The domain is a 5 × 1.5 rectangular tank with a 1 × 1 water column placed at the left corner. The fluids are water and air. The Reynolds number for the simulation is chosen to be 43000, while the Froude number is unity. The domain is discretised using hexahedral elements. The simulation is carried out using a constant time step of t = 0.001 until t=2.5. The schematic diagram is shown in Fig. 1.1. The values of dynamic viscosity (μ) are calculated from the following relation:







Figure 1.1: Collapse of Water Column



Results:

Initial position and position of the water column after 2 sec has been shown in Fig. 1.2 and 1.3 respectively. The position of the water front and height of water column has been compared with the benchmark result of Martin and Moyce [1] and is shown in Figs. 10.4 and 10.5. The results are found to be in good agreement with the published results.



Figure 1.2: Initial position of water column



Figure 1.3: Position of water front after 2 seconds



Figure 1.4: Comparison of dam front



Figure 1.5: Comparison of dam height

References

[1] Martin J.C. and Moyce W. (1952) ‘An experimental study of collaspe of liquid column on the rigid horizontal plan’, Mathematical and Physical Sciences, vol. 244, pp. 312–324.