Hi,
Not sure if this is the best place to put this thread, or in the mechanical/civil engineering section. It's in the civil secn as well but noticed that there wasn't much activity there, If you could let me know I can change it if it's better suited elsewhere, thanks.
Anyway, I'm having a bit of a problem regarding some experiments I carried out. It involved forced oscillation testing of a midwater arch, which is used in oil fields. The arch was oscillated at various amplitudes and frequencies in order to determine the 2 coefficients of the Morison eqn:
F = 1/2 p Cd Xd [Xd] + Cm p V Xdd (p = rho , Xd = velocity, Xdd = accn, Cd and Cm the constants which I need)
I have created a worksheet that will analyse the data and give results for Cd and Cm. The problem is that the results I am getting are not what I expect. Cd is very small, and Cm is very large. I am not sure if this is something I have overlooked in Mathcad, or is a theoretical error. I was told that you guys might be able to help, which is why I'm posting.
If you can offer any suggestions, or see any glaring errors, it would be very much appreciated.
Data 1-3 refers to the axial direction at 0.2, 0.3 and 0.5Hz. Data 4-6 the transverse at the same freqs. Data 10-12 is the files for the experimental set up which has to be subtracted from the overall force to give the force on the model alone.
There is a data 7-9 but I haven't uploaded as file size too large. The only input in the sheet required is to choose a file at the top in the drop down box, and then choose a corresponding file in the Processing for Sting region.