Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 853852 for flyrotary@lancaironline.net; Sun, 03 Apr 2005 23:07:09 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=echristley@nc.rr.com Received: from [192.168.0.10] (cpe-065-187-243-074.nc.res.rr.com [65.187.243.74]) by ms-smtp-04-eri0.southeast.rr.com (8.12.10/8.12.7) with ESMTP id j3436KL4012341 for ; Sun, 3 Apr 2005 23:06:21 -0400 (EDT) Message-ID: <4250AF28.90107@nc.rr.com> Date: Sun, 03 Apr 2005 23:06:16 -0400 From: Ernest Christley User-Agent: Mozilla Thunderbird 1.0.2-1.3.2 (X11/20050324) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Cooling -Learned a lot References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Symantec AntiVirus Scan Engine Ed Anderson wrote: >Higher (molecular velocity) pressure means more contacts (per unit time) >between the air molecules responsible for carrying away the heat from the >core fins/walls. The number of air molecules (density) has not changed, >just their velocity which has increased due to the energy in the incoming >airstream. Remember the diffuser slows the velocity but increases the >pressure and does nothing to the density (as subsonic speeds). > >Have I confused everyone enough for one evening? This is my interpretation >and no other party should be blamed. > >Ed >----- Original Message ----- >From: "George Lendich" >To: "Rotary motors in aircraft" >Sent: Sunday, April 03, 2005 9:25 PM >Subject: [FlyRotary] Re: Cooling -Learned a lot > > So, we're back to that Bernoulli guy. Increasing the speed decreases the pressure, because all the little molecules are running together in one direction instead of banging into things on either side. But this time we're working it in reverse. We're lowering the speed (by slowly increasing the duct's cross sectional area), giving them a chance to knock up against things they wouldn't otherwise (like the radiator core's fins). This leads me to believe that with the proper duct, you could decrease the fin density and allow the air to flow through without the need to generate all that turbulance. You create the turbulance to keep the air mixed (so the cooler air gets a chance to grab some heat). But if the molecules are already picking up the heat there's no need to waste enery making tiny little vortexes all over the place. Am I dreaming again? -- This is by far the hardest lesson about freedom. It goes against instinct, and morality, to just sit back and watch people make mistakes. We want to help them, which means control them and their decisions, but in doing so we actually hurt them (and ourselves)."