RE: Seismic response of hydraulic oil tank

From: <Ben>
Date: Mon Oct 03 2005 - 20:28:00 EDT

How about fuel cell for race car?
For example: <a href="http://www.atlinc.com/fuelcell.htm">http://www.atlinc.com/fuelcell.htm</a>

Ben

-----Original Message-----
From: <a href="/group/PipingDesign/post?postID=VlOPLvVWoOFnN8FH7S_qfcmGU-7lx7EbB4hSJZ8qE93KOb9tsxlgj7BF2UJU9xmE779qfvVxfu3Obbg-6XQAnMKN">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=VlOPLvVWoOFnN8FH7S_qfcmGU-7lx7EbB4hSJZ8qE93KOb9tsxlgj7BF2UJU9xmE779qfvVxfu3Obbg-6XQAnMKN">PipingDesign@yahoogroups.com</a>] On Behalf Of Steve McKenzie
Sent: Monday, October 03, 2005 5:35 AM
To: <a href="/group/PipingDesign/post?postID=VlOPLvVWoOFnN8FH7S_qfcmGU-7lx7EbB4hSJZ8qE93KOb9tsxlgj7BF2UJU9xmE779qfvVxfu3Obbg-6XQAnMKN">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] Seismic response of hydraulic oil tank

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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