Steve
I have used the following document occasionally for this problem:
U.S. Atomic Energy Commission "Nuclear reactors and earthquakes", TID-7024 Appendix F "Dynamic analysis of Fluids in Containers subjected to accelerations", Washington DC, 1963
Since 1963 there have been many papers on this topic published, most of them not easy to digest. I use the above because the USEAC gives it some authority. It should be in the public domain. I have a copy if required. I think nowadays many people use CFD for this problem. If you are interested I can give you the details of some papers on this topic.
10 g at a period between 0.15 and 0.2 seconds seems very high to me. Is the equipment located high in a building'
Theo Schotten
> Gents
>
> have been asked to have a look at a couple of hydraulic/lube oil
> power pack tanks, from a seismic perspective.
> The larger has a volume of around 2.65m^3
> The nominated ground acceleration is 10g if the natural frequency is
> within 0.15-0.2 seconds; otherwise 5g. Maximum ground displacement is
> given as 60mm, all directions.
>
> Question 1: does anyone have a reputable calculation reference for
> the natural (slosh) frequency of a rectangular tank with known
> dimensions, fill depth fluid density and viscosity?
>
> Question 2: It appears to me that unless the vibration spectrum is
> known, it is not possible to calculate the stresses in the tank walls.
> For a single shot, the additional peak stresses would be somewhat
> less than 5 or10 times those generated by the hydrostatic case alone.
> However if the exciting frequency matches the natural frequency, then
> some fairly intense loads could be generated, although it seems
> fairly unlikely. Has anyone seen a design solution for designing
> rectangular tanks subject to this type of loading? I imagine it
> should be reasonably common for ships, planes, autos and the like,
> but I dont seem to have anything on the shelves.
> I may wimp out and baffle the tank so the oil moves as a solid mass,
> but this is rather inelegant and may cause air release (letting the
> gas bubbles rise to the top) problems.
>
> Thanks in anticipation.
> Cheers
>
> Steve
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Received on Mon Oct 03 11:11:00 2005
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