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From: "george lendich" <lendich@optusnet.com.au>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-1088432@logan.com>
Subject: Re: [FlyRotary] Re: new hangar
Date: Wed, 3 May 2006 09:53:51 +1000
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Ed,
Looking at that design ( which is very interesting) would you need more than
one 5" cone - I would suggest not.
Mine and Bill's design don't have holes in the cone, but merely used the
cone to redirect the shock wave.
I must say I do like this particular design, but I wonder how well it works,
it looks interesting enough to work well.
George ( down under)

> Hadn't really thought about it, Bob.  But, I would say they need to be
make
> out of SS (304, 316 or 321), would need at least a 30-45 deg angle to the
> cone and be a min of 0.090 thick.  The diameter would depend on the size
of
> tube being used. I would think not smaller than around 2 1/2 - 3".  They
> would need some perforations punched in the metal before making them into
> cones.  The idea is to break up the shock wave but not seriously hinder
the
> flow of gas.  This is the design that you see on the market for exhaust
> inserts.  See this URL
>
>
http://www.secureperformanceorder.com/dynatechstore/getproduct.cfm?CategoryI
D=30&ClassID=278&SubclassID=1309&ProductID=2476
>
> (Note: need to past both halves of URL address into your browser's address
> window).
>
>
> From what I think I understood in reading about exhausts, my idea was to
> have a series of cones in a tube such that the would form a series of
> expansion chambers.   The cone would force the exhaust gas against the
sides
> of the tube (area between cone and tube), then expand into a chamber
between
> a pair of cones and then again have the gas forced against the outside (to
> the tube wall) by a  cone and then into another expansion chamber.
> Supposedly this contraction/expansion is good for reducing the shock wave.
>
> I do know that after several experiments that 1/8" thick stainless steel
> just won't stand up to the shock wave of a turbo block (without exhaust
> splitters) for any period of time if oriented perpendicular to the shock
> wave.
>
>
>
> Ed
> ----- Original Message -----
> From: "Bob Perkinson" <bobperk@bellsouth.net>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Tuesday, May 02, 2006 7:26 AM
> Subject: [FlyRotary] Re: new hangar
>
>
> > Ed,
> > What would be the dimensions of the cones if someone were to make them?
> >
> > Bob Perkinson
> > Hendersonville, TN.
> > RV9 N658RP Reserved
> > If nothing changes
> > Nothing changes
> >
> >
> >
> >
> >
> >
> > Sounds like the right formula, George - will wait for your project's
> > outcome
> > before I try cones.  Yes, I did find some cone  inserts at $60.00 USD
> > each.
> > I would need 4 for my two tubes - hummm makes one tube sound better all
> > the
> > time.
> >
> > Ed
> >
> >>
> >>> Just the shells, TJ, the 1/8" thick SS washers are history.  I have
> >>> concluded that no reasonable thickness of metal will stand up to the
> >> exhaust
> >>> pulse for long if it is perpendicular to the shock wave.  I believe
that
> >> if
> >>> I could shape them into cones where by the shock wave would hit the
side
> >> of
> >>> the cone  at an oblique angle  would probably survive - now all I have
> >>> to
> >> do
> >>> is find some {:>).
> >>>
> >>> Ed
> >>
> >> Ed,
> >> There plenty of SS cones available in 1.6mm, I'm using them in my
exhaust
> >> which is a joint venture design with Bill Jepson - the idea is to
> >> redirect
> >> the shock waves but not restrict the exhaust, as you have alluded to.
> >> George ( down under)
> >
> >
> > --
> > Homepage:  http://www.flyrotary.com/
> > Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
> >
>
>
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/