Thanks Theo
I'll do a search for the USAEC stuff, and get back to you if I luck out. In this case I think the high acceleration may be due to the criticality of the service; expect the power pack is required to operate in order to make things safe during/after an earthquake.
Cheers
Steve
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From: <a href="/group/PipingDesign/post?postID=LEHhyoNFxdfusofMjPoAaZTfnMB0Wo9OYED0yNQp73UjmWMnE4NGBzM9L8qXfAUhbp8qU5CmsPDk3l_6LggkZigpnBs">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=LEHhyoNFxdfusofMjPoAaZTfnMB0Wo9OYED0yNQp73UjmWMnE4NGBzM9L8qXfAUhbp8qU5CmsPDk3l_6LggkZigpnBs">PipingDesign@yahoogroups.com</a>]
On Behalf Of Theo Schotten
Sent: Tuesday, October 04, 2005 4:11 AM
To: <a href="/group/PipingDesign/post?postID=LEHhyoNFxdfusofMjPoAaZTfnMB0Wo9OYED0yNQp73UjmWMnE4NGBzM9L8qXfAUhbp8qU5CmsPDk3l_6LggkZigpnBs">PipingDesign@yahoogroups.com</a>
Subject: Re: [PipingDesign] Seismic response of hydraulic oil tank
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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Yahoo! Groups Links Received on Sat Sep 03 16:15:00 2005
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