Sloshing vertical natural frequency

[serbring]

Hi,

I need to estimate the sloshing natural frequency, in the three axis of a rectuangular tank, not fully filled of liquid. I need this for understading how changes the vehicle dynamics in some trucks. I have found a linear formula for the horizontal direction, but I have found nothing about the vertical one. Any suggestion about this?

Thank you very much

 

[AlephZero]

You probably can't find a formula because a liquid can't "slosh vertically". The only way it could do that is to change its volume, but most liquids are almost incompressible (unless you are talking about a liquid containing gas bubbles, or something similar).

When it "sloshes horizontally", of depth of liquid increases at one end of the tank and decreases at the other, and the volume stays constant. There is vertical motion in the fluid as well as horizontal motion.

 

[serbring]

Hi AlephZero,

thanks for your answer, maybe does the vertical excitation influence the horizzontal sloshing? Do you know in which way? I have created a simple mechanical model in which I have found the equivalent mass, equivalent damper and spring coefficient, but this works only for horizantal excitation. Try to take a look to formula 5 on this link:

http://pedago.cegepoutaouais.qc.ca/media/0260309/0378334/SCGC-BON/Documents/ST099-Tait-Damatty.pdf

But how is it changes in precesence of horizontal and vertical excitation?
Thanks