Re: [PSUBS-MAILIST] Re: Welcome, apologies and multi-hulls.

[emm03@mirapoint.uow.edu.au]

Well, sure. I can imagine that it isnt cheap to go deep.
When you quote the higher costs, are you comparing that with 
a monolayer hull that can go as deep?
EM.



---- Original message ----
>Date: Wed, 29 Jan 2003 07:48:03 +0800
>From: "Warrend Greenway" <dub@linuxmail.org>  
>Subject: Re: [PSUBS-MAILIST] Re: Welcome, apologies and 
multi-hulls.  
>To: personal_submersibles@psubs.org
>
>Doing some rough calculations I come up with 20% higher
>cost to fabricate a hull this way. There is on other flaw
>in the theory: How will you couple a, say, hatch collar, 
>viewport flange, etc. through the hull layers? The stresses
>at the junctions get astronomically high...
>
>Warren.
>
>> Hi People.
>> In an attempt to make up for my embarrasing, unhelpful, 
and 
>> narrowminded comments I made earlier. I would propose some 
>> more discussion on this idea of 'compartmentalising'.
>> (please excuse any spelling mistakes, I dont possess the 
>> apparent intellectual capacity of some giants on this list)
>> 
>> Is there any merit in using a multi-layer hull? 
>> 
>> For a single layer hull for an ambient machine, the 
pressure 
>> differential is at a maximum. If we were to use TWO layers 
>> (or more) in the pressure hull, and partially pressurise 
the 
>> layers in between, then is it not possible to sustain a 
>> greater TOTAL pressure differential?
>> 
>> I am now going to attempt to draw an ascii 
illustration..ahem.
>> 
>> The traditional method:
>> 
>>        |
>> Inside | Outside
>>    @   |    @
>>   1atm |  4 atm
>>        |
>> 
>> 
>> pressure differential = 3 atm.
>> Depth ~30m
>> 
>> 
>> A multilayer hull:
>> 
>>         |           |
>> inside  | Intermed. | Outside 
>>   @     |   @       |  @
>>  1 atm  |  4 atm    |  7 atm
>>         |           |
>> 
>> Pressure differential per layer is still at 3 atm. 
>> Outside depth ~ 70m
>> 
>>  If I have this right..I think I have it vaguely correct,
>> compartmentalising might be a really good way to get to 
>> greater depths. I know this sort of thing has been 
discussed 
>> before, but I am too lazy to look up the archives..
>> My apologies for any spelling mistakes Herve, I hope you 
can 
>> overlook them just this once.
>> If I have overlooked any fundamental physics of 
hydrodynamics 
>> and hydrostatics, please be nice!
>> 
>> Thanks!
>> EM.
>> 
>> 
>> 
>> 
>> 
>> ---- Original message ----
>> >Date: Tue, 28 Jan 2003 16:21:43 EST
>> >From: BauWauHausDesign@aol.com  
>> >Subject: Re: [PSUBS-MAILIST] Re: Welcome to the 
>> Personal_Submersibles_Disc ussion  
>> >To: personal_submersibles@psubs.org
>> >
>> >   In a message dated 1/27/03 5:56:13 PM Pacific
>> >   Standard Time, dub@linuxmail.org writes:
>> >
>> >     Even if it increased to ambient, or even half of
>> >     ambient, you would not
>> >     be able to withstand the bodily strain at the
>> >     depths in question.
>> >
>> >     Warren.
>> >
>> >   provided that the pressure is ambiant. what if you
>> >   were able to stratify pressure zones without a
>> >   structural membrane (ie cockpit, pressure suit...)?
>> >   to say it is not possible is to deny many example in
>> >   nature that rely on non-compartmentalized stratified
>> >   pressure zones to exist.
>> >
>> >   jeffrey
>> 
>
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