X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3646599 for flyrotary@lancaironline.net; Tue, 19 May 2009 05:25:54 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from mail.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id 20D4F173BCA for ; Tue, 19 May 2009 17:24:53 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by mail.aanet.com.au (Postfix) with SMTP id A2BBA461538 for ; Tue, 19 May 2009 16:41:50 +0800 (WST) Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Phonic Band gap filter Date: Tue, 19 May 2009 18:41:53 +1000 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 0617-3, 04/28/2006), Outbound message X-Antivirus-Status: Clean Al, I would off- set the tubes, the idea is to not have a direct path for the sound waves to travel in a direct line, front to back (path of least resistance) make them stainless and of a reasonable thickness. George (down under) > Maybe there is a way to get both. This is the first results from my > experiments with bandgap filters that I just did today. > > http://ernest.isa-geek.org/Delta/Experiments/PhononicBandgapFilter.html > > Ernest; > > How are you defining 'filling fraction' ? > > Al > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html >