X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4499894 for flyrotary@lancaironline.net; Sat, 09 Oct 2010 19:31:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=ZBI6RdNETH4sDdlJjm+X1V76MXTYJ4j6p+Mc58whUtE= c=1 sm=0 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=o0ApMVEk_vabEkVbx1QA:9 a=6HJTFPG85ls6_jBbHQy8EhpWd0AA:4 a=pILNOxqGKmIA:10 a=E93lBu2AAAAA:8 a=K3SRHu4mq8jKfkyAVq4A:9 a=t7nz-kMv3SBU3MJrtIIA:7 a=oJTPFFua6htgfSVpN6V0E35xjskA:4 a=hO30gm18fF0A:10 a=MpuOTR30KwMA:10 a=FOUTPhXFUAcA:10 a=zgjei8Deq7QA:10 a=NWVoK91CQyQA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:65320] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id 95/DF-08566-F2BF0BC4; Sat, 09 Oct 2010 23:30:55 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" Subject: Solidity of Prop Disc Date: Sat, 9 Oct 2010 19:30:41 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01CB67E8.7575A930" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_002D_01CB67E8.7575A930 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Some more interesting tidbits on Prop parameters Regarding steps that could be taken after diameter and pitch parameters = are considered for increasing thrust. Increasing the blade chord or = the number of blades. Both have the effect of increasing the solidity of = the propeller disk. Solidity simply refers to the area of the propeller = disk occupied by solid components (the blades) versus that area open to = the air flow. As solidity increases, a propeller can transfer more power = to the air. (provide you have the power available - otherwise the = increased load will diminish the prop/engine rpm resulting in less power = and performance) While increasing the blade chord is the easier option, it is less = efficient because the aspect ratio of the blades is decreased resulting = in some loss of aerodynamic efficiency. Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com ------=_NextPart_000_002D_01CB67E8.7575A930 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Some more interesting tidbits on Prop=20 parameters
 
Regarding steps that could be taken after = diameter and=20 pitch parameters are considered for increasing=20 thrust.   Increasing the blade chord or the number of = blades.=20 Both have the effect of increasing the solidity of the propeller = disk.=20 Solidity simply refers to the area of the propeller disk occupied by = solid=20 components  (the blades) versus that area open to the air flow. As = solidity=20 increases, a propeller can transfer more power to the air. (provide = you have=20 the power available - otherwise the increased load will diminish the = prop/engine=20 rpm resulting in less power and performance)
 
While increasing the blade chord is the easier = option, it=20 is less efficient because the aspect ratio of the blades is decreased = resulting=20 in some loss of aerodynamic efficiency.
 
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
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