<HTML><HEAD></HEAD><BODY><font face="Courier New" size=2>It would be not
so easy to make 1/10 T- frames
or welds.. </font><BR><BR>"hank pronk via
Personal_Submersibles" <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>>
schrieb:<BR>> <BR>> Hi Cliff<BR>> Thank you, that is perfect.
<BR>> Hank--------------------------------------------<BR>> On
Tue, 12/30/14, Cliff Redus via Personal_Submersibles <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>>
wrote:<BR>> <BR>> Subject: Re: [PSUBS-MAILIST] model
testing<BR>> To: "Personal Submersibles General Discussion" <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
Received: Tuesday, December 30, 2014, 9:44 AM<BR>> <BR>>
Hank,<BR>> just to bring closure to this thread. Stress on the
boat<BR>> due to depth scales geometrically between motel
and<BR>> prototype. Drag scales based on Reynolds<BR>>
number.<BR>> As an example<BR>> for stress, go to Psubs.org flat
acrylic viewport calculator<BR>> that Jon coded based on PVHO <a
href="http://www.psubs.org/design/viewports/1ATMFD/">http://www.psubs.org/design/viewports/1ATMFD/</a><BR>>
Put in a 500 ft depth and a 10"<BR>> viewable diameter Di and
record all results for the acrylic<BR>> viewport. Repeat with
same depth but 1/10" the<BR>> viewable diameter, i.e., 1" and record
results. Note<BR>> that all dimension scale
geometrically. This is based on<BR>> the assumption that the
material is isotropic. These<BR>> results would not be true
for anisotropic materials like a<BR>> carbon fiber layup were
material properties are <BR>> directional dependent.
Additionally for carbon fiber, you<BR>> would not be able to scale
the scale the size of the<BR>> fibers.<BR>> So if you
are<BR>> using an isotropic material such as steel, and can
fabricate<BR>> a dimensionally corrected scaled model of a
component like<BR>> a pressure hull including details like weld
filler size,<BR>> then crush depth observed in the motel test cell
would match<BR>> the full scale prototype. Like
any experiment, you would<BR>> need multiple test to average
the results.<BR>> Cliff<BR>> <BR>> <BR>> <BR>>
<BR>> Cliff Redus<BR>> Redus Engineering<BR>> USA<BR>>
mobile: 830-931-1280<BR>> <A
href="mailto:cliffordredus@sbcglobal.com">cliffordredus@sbcglobal.com</a>
<BR>> From: hank pronk via<BR>>
Personal_Submersibles<BR>> <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
<BR>> To: Personal<BR>> Submersibles General Discussion<BR>>
<<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>>
<BR>> <BR>> Sent: Monday,<BR>> December 29, 2014 2:41
PM<BR>> Subject: Re:<BR>> [PSUBS-MAILIST] model testing<BR>>
<BR>> <BR>> <BR>> I am not<BR>> looking for drag
comparisons, I am looking for failure due<BR>> to pressure
comparisons. I though I read that the Nekton<BR>> subs<BR>>
were built as a model first to establish crush depth.<BR>>
Hank<BR>> --------------------------------------------<BR>> On
Mon, 12/29/14, Cliff Redus via<BR>> Personal_Submersibles <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
wrote:<BR>> <BR>> Subject: Re:<BR>> [PSUBS-MAILIST] model
testing<BR>> To:<BR>> "Personal Submersibles General
Discussion" <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
Received: Monday, December 29, 2014, 3:06<BR>> PM<BR>>
<BR>> Drag<BR>> <BR>> results between a model and full
scale does not scale<BR>> geometrically. You have to scale
model and<BR>> full scale off<BR>> the dimensionless
Reynolds<BR>> number. Reynolds number<BR>>
scaling<BR>> enables you to scale results between model and
full<BR>> scale using either a water tunnel or air<BR>>
tunnel.<BR>> Cliff<BR>> <BR>> <BR>> <BR>>
From: Alan James via<BR>>
Personal_Submersibles<BR>> <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
<BR>> To: Personal<BR>> Submersibles General
Discussion<BR>> <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
<BR>> <BR>> Sent: Monday,<BR>> December 29, 2014 1:55
PM<BR>> <BR>> Subject: Re:<BR>> [PSUBS-MAILIST]
model<BR>> testing<BR>> <BR>> <BR>>
Hank,I just ran<BR>> a test on my<BR>> pressure program &
you get the same crush<BR>> depthon a<BR>> sphere of
A516-70<BR>> steel that is 1000mm diameter & 10mm<BR>>
<BR>> thick as youdo on a<BR>> sphere 100mm diameter<BR>>
& 1mm thick.What I am<BR>> not sure of is if<BR>> you can
scale up the drag results on a<BR>> <BR>> model.If you<BR>>
have a scale model that is<BR>> 1/50th & it takes X amount
of<BR>> force to<BR>> push<BR>> it at 3<BR>>
knots, can<BR>> you multiply X by 50 to get the required<BR>>
<BR>> thrust?Alan<BR>> <BR>> <BR>>
<BR>> From: Brian Cox<BR>> via<BR>>
Personal_Submersibles<BR>> <BR>> <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
<BR>> To: Personal<BR>> Submersibles General
Discussion<BR>> <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
<BR>> <BR>> Sent: Tuesday,<BR>> December 30, 2014 8:43
AM<BR>> <BR>> Subject: Re:<BR>> [PSUBS-MAILIST]
model<BR>> testing<BR>> <BR>> <BR>>
Hank,<BR>> I would say<BR>> no. It
would have to be so exact that it<BR>> would be<BR>> virtually
impossible to<BR>> extrapolate from the small model,<BR>>
and<BR>> aside from that I think there are other<BR>>
engineering<BR>> principles involved that would<BR>> come into
play , Sean would<BR>> be the person<BR>> to ask ! I
know that it is done in wave<BR>> <BR>> tanks and wind tunnels,
but in those you are looking at<BR>> laminar flow and such things,
not structural<BR>> strength so<BR>> much. You might be
able to<BR>> get a rough idea of how it<BR>> would start
to<BR>> collapse maybe. The larger the model the<BR>>
<BR>> better I would think.<BR>> <BR>> <BR>>
Brian<BR>> <BR>> --- <A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a><BR>>
wrote:<BR>> <BR>> <BR>> From: hank pronk via<BR>>
Personal_Submersibles<BR>> <<A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><BR>>
To: <A
href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a><BR>>
Subject: [PSUBS-MAILIST] model testing<BR>> Date: Mon, 29 Dec
2014 10:52:46 -<A href="callto:0800">0800</a><BR>> <BR>> Hi
all<BR>> If<BR>> you<BR>> make a scale model of a
submarine in<BR>> complete detail. <BR>> Scale the size
and metal<BR>> thickness, is it a reasonable<BR>> <BR>>
representation of depth capabilities when pressure<BR>>
tested?<BR>> Hank<BR>> <BR>>
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