X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db03.mx.aol.com ([205.188.91.97] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5481414 for flyrotary@lancaironline.net; Sat, 14 Apr 2012 11:40:35 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.97; envelope-from=CozyGirrrl@aol.com Received: from mtaomg-da03.r1000.mx.aol.com (mtaomg-da03.r1000.mx.aol.com [172.29.51.139]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id q3EFdvWJ004416 for ; Sat, 14 Apr 2012 11:39:57 -0400 Received: from core-dsa001b.r1000.mail.aol.com (core-dsa001.r1000.mail.aol.com [172.29.252.65]) by mtaomg-da03.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 129CDE000087 for ; Sat, 14 Apr 2012 11:39:57 -0400 (EDT) From: CozyGirrrl@aol.com Message-ID: <1fd.7370ba01.3cbaf44c@aol.com> Date: Sat, 14 Apr 2012 11:39:57 -0400 (EDT) Subject: Re: [FlyRotary] Re: Laser Ignition, was: [FlyRotary] Re: The 16X is A L I V E... To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_1fd.7370ba01.3cbaf44c_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [70.242.64.213] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1334417997; bh=mkm9+fBZvzpZuI4b6dhEwWYVqr6AkaVfhSMRfByhJvU=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=bqBRlRLp5+zvjrFNDaoQdI/MweZw9cvfsElVC2zdYL9tY92nrm74piaenDofW9XIi MAHic+w5D1qXUCQvjNNbQ4YZ64Lkwvkvc5bbtp3Xi0pFxOOpZleA6QSZPOBWOrwo0D qq1EvF39gViCOgatrZVhUHBcrvtaKyS4EgY/bzRg= X-AOL-SCOLL-SCORE: 0:2:442007072:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338b4f899a4d1a8d --part1_1fd.7370ba01.3cbaf44c_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Ran this by a girlfriend who gets to play with weapon grade energy stuff, she blew a hole through her kitchen wall with a single pulse from a homebrew laser in college, glad she's on our side. My greatest concern is that in the lab under ideal conditions a laser sounds great, under the hood in the real world is another matter, at 10k ft a serious matter. She plays with this stuff every day, here is her reply: /begin Subj: Re: laser ignition Hey there, No, that doesn't make a lot of sense. Not only is the window issue a serious problem that I don't know how you would overcome. There is also an issue of heat. A solid state laser has a really crappy mode so in order to get the fluence needed to ignite the fuel, the laser would have to be in the near-field. Diffraction losses past this point will not let the beam focus tight enough to have enough energy to heat anything sufficiently for ignition. With the laser being this close to the engine, heat becomes a serious problem. As the lasers temperature changes, more than a couple of degrees C, the wavelength shifts. A change of 2 degrees C can cause a solid state (diode) laser to shift wavelength enough where it is no longer at the proper resonance and the power drops significantly. Even with active cooling on the laser, which would be required, the heat of the engine would probably be greater than what a TC cooling device can handle. A higher power DPSS style laser could be used and launched into fiber which could solve the heat problem but now you have the grime and combustion by-products in the engine that would definitely foul a fiber or an optical window which would induce diffraction and cause a fluence drop. So, I personally don't see how they could make this work. Or even why for that matter. High voltage is cheap and has worked well for over 100 years. /end It's her last paragraph that concerned me the most. I spent 20 years working with HID systems focused into fiber optics. Her last sentence says it all. I am not against innovation but I am very cautious. Chrissi & Randi _www.CozyGirrrl.com_ (http://www.cozygirrrl.com/) CG Products, Custom Aircraft Hardware Chairwomen, Sun-N-Fun Engine Workshop In a message dated 4/13/2012 11:38:05 A.M. Central Daylight Time, echristley@att.net writes: CozyGirrrl@aol.com wrote: > And all this will work only if the combustion chamber is always squeaky > clean, no deposits or film on the windows, once that happens it all goes > to heck quickly. > If you've got a film building up on the rotor housing's chrome face, aren't you behind the curve already? I could see it being a problem in a piston cylinder's head. I've had to chip off gunk with a screwdriver it had built up so thick. But they aren't constantly being wiped by an apex seal like in a rotary. -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html --part1_1fd.7370ba01.3cbaf44c_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Ran this by a girlfriend who gets to play with weapon grade energy stu= ff,=20 she blew a hole through her kitchen wall with a single pulse from a homebre= w=20 laser in college, glad she's on our side.
My greatest concern is that in the lab under ideal conditions a laser= =20 sounds great, under the hood in the real world is another matter, at 10k ft= a=20 serious matter.
She plays with this stuff every day, here is her reply:
 
/begin
Subj: Re: laser ignition
 
Hey there,=20
No, tha= t doesn't=20 make a lot of sense.  Not only is the window issue a serious problem t= hat I=20 don't know how you would overcome.  There is also an issue of heat. &n= bsp;A=20 solid state laser has a really crappy mode so in order to get the fluence n= eeded=20 to ignite the fuel, the laser would have to be in the near-field.=20  Diffraction losses past this point will not let the beam focus tight= =20 enough to have enough energy to heat anything sufficiently for ignition.=20  With the laser being this close to the engine, heat becomes a serious= =20 problem.  As the lasers temperature changes, more than a couple of deg= rees=20 C,  the wavelength shifts.  A change of 2 degrees C can cause a s= olid=20 state (diode) laser to shift wavelength enough where it is no longer at the= =20 proper resonance and the power drops significantly.  Even with active= =20 cooling on the laser, which would be required, the heat of the engine would= =20 probably be greater than what a TC cooling device can handle.
A highe= r power=20 DPSS style laser could be used and launched into fiber which could solve th= e=20 heat problem but now you have the grime and combustion by-products in the e= ngine=20 that would definitely foul a fiber or an optical window which would induce= =20 diffraction and cause a fluence drop.  So, I personally don't see how = they=20 could make this work.  Or even why for that matter.  High voltage= is=20 cheap and has worked well for over 100 years.
/end
 
It's her last paragraph that concerned me the most. I spent 20 years= =20 working with HID systems focused into fiber optics. Her last sentence says = it=20 all.
I am not against innovation but I am very cautious.
Chrissi &=20 Randi
www.CozyGirrrl.com
C= G=20 Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop=
 
In a message dated 4/13/2012 11:38:05 A.M. Central Daylight Time,=20 echristley@att.net writes:
= CozyGirrrl@aol.com wrote:
> And all this will work only if= the=20 combustion chamber is always squeaky
> clean, no deposits or film o= n the=20 windows, once that happens it all goes
> to heck quickly.
>&n= bsp;=20

If you've got a film building up on the rotor housing's chrome fa= ce,=20 aren't you behind the curve already?  I could see
it being a prob= lem=20 in a piston cylinder's head.  I've had to chip off gunk with a=20 screwdriver it had built up so thick.
But they aren't constantly being= =20 wiped by an apex seal like in a rotary.

--
Homepage: =20 http://www.flyrotary.com/
Archive and UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
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