Return-Path: Received: from rtp-iport-2.cisco.com ([64.102.122.149] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 763523 for flyrotary@lancaironline.net; Mon, 28 Feb 2005 17:25:52 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.102.122.149; envelope-from=echristl@cisco.com Received: from rtp-core-1.cisco.com (64.102.124.12) by rtp-iport-2.cisco.com with ESMTP; 28 Feb 2005 17:25:07 -0500 X-BrightmailFiltered: true X-Brightmail-Tracker: AAAAAA== Received: from [172.18.179.151] (echristl-linux.cisco.com [172.18.179.151]) by rtp-core-1.cisco.com (8.12.10/8.12.6) with ESMTP id j1SMP51j022363 for ; Mon, 28 Feb 2005 17:25:05 -0500 (EST) Message-ID: <42239A41.6090408@cisco.com> Date: Mon, 28 Feb 2005 17:25:05 -0500 From: Ernest Christley User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20040929 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] flow measurements References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Jim Sower wrote: > > My guess is that we're pretty much clueless. Pretty much, but not completely. Pump manufacturers provide flow charts that will give you the flow rate against a head pressure. Davie-Craig's chart even provides this information for various voltage levels. Measuring a differential pressure across the pump and it's input voltage is trivial enough. Reference the chart, and (unless someone is lying) you have a dependable flow rate. http://ernest.isa-geek.org/Delta/Library/ewpv.xls