X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1021766 for flyrotary@lancaironline.net; Sat, 25 Jun 2005 23:02:40 -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 j5Q31qL4024052 for ; Sat, 25 Jun 2005 23:01:53 -0400 (EDT) Message-ID: <42BE1AA0.90604@nc.rr.com> Date: Sat, 25 Jun 2005 23:01:52 -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] Single Rotor Research 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 George Lendich wrote: > > It would also seem that if you radiused the following edge of the > exhaust outlet, it provides better exhaust flow and less contamination > of the inlet charge at idle. > For your digestion! OK. I'm about done digesting, so... This is completely logical, under the theory that the sharp edge will trip the exiting airflow into turbulence. Clean air always flows faster. I keep thinking about the exhaust inserts. Ed has the opinion that they must be eating up horses to give the noise reduction by causing back pressure. But what if the inserts work like a fowler flaps and just helps the gas to exit is an orderly manner vs all turbulated? Aren't laminar flow aircraft typically quieter than turbulent flow ones? Has anyone compared the noise produced before and after an exhaust has been radiused? Has anyone attempted to 'shape' the inserts so that it has a radiused leading edge and a tapered trailing edge (ie, aerodynamic)? I know they're not very thick, but their thickness is a significant portion of the overal exhaust ports size. -- 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)."