[bruce21]

Hi all,

I am trying to calculate the added mass of a heave plate by forcing an oscillatory heaving motion in vertical direction. The motion is achieved by using a morphing mesh. To validate the model, I am replicating an experiment.

The model produces good results at low amplitudes (at KC ~ 0.2). However, when I increased the amplitude of oscillation, the results get worse with the amplitude. As in, the error increases with increase in KC number.

I use a kW SST model for this. I highly doubt the initialisation of turbulence variables (k, omega and nut) for this problem. I calculate these variables by using Vmax (calculated as Vmax = Amplitude*Angular frequency), and a Turbulence length scale of 0.2*Diameter (of the heave plate). However, I feel this is where I am going wrong.

Can someone give your opinion on this approach? Is there another method you would suggest to calculate the initial values?

It would be reallly great if you can share a sample (validated) file so that I can compare our models to see where I am going wrong.