X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.3.6) with ESMTP id 4242601 for flyrotary@lancaironline.net; Fri, 30 Apr 2010 08:35:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=5P0OTAIvinzEaQSdIWNVj4QBj9yXk/aSyuZ47IbBFeY= c=1 sm=0 a=jWi4rv2f9FMA:10 a=kj9zAlcOel0A:10 a=Er6hwA6a1l4K/FyzC6NN7w==:17 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=vZg4kRPO_z19kapiLW4A:9 a=SZPxitFHMQXB3uOHTFYA:7 a=-avk7RnhBqwQwqL1u-AMFom9s8EA:4 a=CjuIK1q_8ugA:10 a=Qa1je4BO31QA:10 a=1vhyWl4Y8LcA:10 a=EzXvWhQp4_cA:10 a=Er6hwA6a1l4K/FyzC6NN7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 75.181.123.159 Received: from [75.181.123.159] ([75.181.123.159:3775] helo=computername) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id 8D/5B-28107-96ECADB4; Fri, 30 Apr 2010 12:34:49 +0000 From: "Ed Anderson" Message-ID: <8D.5B.28107.96ECADB4@cdptpa-omtalb.mail.rr.com> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Eductor scavenging of radiator outlet Date: Fri, 30 Apr 2010 09:04:48 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook, Build 11.0.5510 In-Reply-To: Thread-Index: AcroU55Yl//cmJfXSxWCaJApCqOiLQADTNGQ X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Interesting, Marc Certainly seems logical that exhausted aided ejection would aid most at low airspeeds. That is certainly a tough cooling scenario - with little air flow. At higher airspeeds (in flight) there should be sufficient air mass flow to cool - just a matter of taking full advantage of it. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Marc de Piolenc Sent: Friday, April 30, 2010 6:54 AM To: Rotary motors in aircraft Subject: [FlyRotary] Eductor scavenging of radiator outlet Ejector cooling (not sure why the posters are calling the device an eductor - that term is reserved for machines that use a current of fluid to move bulk solids) is well worth pursuing. It isn't much pursued because: 1. people follow plans, even if a design has a history of cooling problems 2. ejector cooling is poorly documented in textbooks even though it's been worked on for decades, and research on unsteady-flow ejectors is ongoing. Bruce Carmichael, Mr. Low Speed Aerodynamics, comments in one of his books that cooling drag in typical light aircraft is MANY TIMES what theory predicts it should be, so as other aspects of light airplanes become cleaner and more efficient cooling is the obvious drag abatement target. The immediate benefit of ejector cooling is reliable static cooling during taxi and runup, without stealing precious shaft power for an auxiliary cooling fan. Marc de Piolenc -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html