X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db03.mx.aol.com ([205.188.91.97] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTP id 5083429 for flyrotary@lancaironline.net; Fri, 05 Aug 2011 19:34:56 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.97; envelope-from=Lehanover@aol.com Received: from mtaomg-da05.r1000.mx.aol.com (mtaomg-da05.r1000.mx.aol.com [172.29.51.141]) by imr-db03.mx.aol.com (8.14.1/8.14.1) with ESMTP id p75NYDcF005100 for ; Fri, 5 Aug 2011 19:34:13 -0400 Received: from core-mob003a.r1000.mail.aol.com (core-mob003.r1000.mail.aol.com [172.29.194.201]) by mtaomg-da05.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 1F530E000081 for ; Fri, 5 Aug 2011 19:34:13 -0400 (EDT) From: Lehanover@aol.com Message-ID: <1302.61d4ace9.3b6dd7f4@aol.com> Date: Fri, 5 Aug 2011 19:34:12 -0400 (EDT) Subject: Re: [FlyRotary] Re: Impellor Rotation Direction To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_1302.61d4ace9.3b6dd7f4_boundary" X-Mailer: AOL 9.6 sub 5004 X-AOL-IP: 173.88.24.45 X-Originating-IP: [173.88.24.45] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:430750016:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338d4e3c7df536d1 --part1_1302.61d4ace9.3b6dd7f4_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit All of that, and, or, like a fixed pitch Scimitar propeller blade. The less fancy the wider the operating range. And vice/versa. The performance requirements of automotive pumps are so minimal that just in the last few years have folks been improving water output vice HP input. To improve mileage. Smoother scrolls, even machined impeller faces. Unheard of before now. Lynn E. Hanover In a message dated 8/5/2011 12:47:26 P.M. Paraguay Standard Time, nghthwk@bellsouth.net writes: Jeff, To give the short answer, Mazda is turning the impeller in the correct direction (namely in the direction correlating to the increasing scroll volume, as depicted in your "Water Pump Pulley 03.jpg"). The long answer is that the impeller blades, oriented as they are, is a stable, wide operating band style impeller. To use an aircraft analogy, this pump has a positive static margin. Something that's interesting about pumps such as this is that they can squeeze more efficiency out of the impeller by rotating the blade on the impeller. The downside to increasing the efficiency in this manner is that the operating range is reduced and, similar to reducing the static margin in an airplane, is that you pay for it in stability. If a pump of this design were "flying" at its neutral point, the blades would be oriented radially from the axis of rotation. Continuing with the airplane analogy, if the pump were "flying" with negative static margin, but also at its most potentially efficient, but also most likely to cavitate and go unstable, the blades would be mirror-imaged from the orientation they're in now, but still rotating in the same direction. I'm sure what I've explained is clear as mud, yes? Anyway, hope it helps. Regards, Cedric Gould --part1_1302.61d4ace9.3b6dd7f4_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
All of that, and, or, like a fixed pitch Scimitar propeller blade. The= less=20 fancy the wider the operating range. And vice/versa. The performance=20 requirements of automotive pumps are so minimal that just in the last few y= ears=20 have folks been improving water output vice HP input.
To improve mileage. Smoother scrolls, even machined impeller faces.=20 Unheard  of before now.
 
Lynn E. Hanover
 
In a message dated 8/5/2011 12:47:26 P.M. Paraguay Standard Time,=20 nghthwk@bellsouth.net writes:
= Jeff,

To give the short answer, Mazda is turning the= =20 impeller in the correct
direction (namely in the direction correlatin= g to=20 the increasing scroll
volume, as depicted in your "Water Pump Pulley= =20 03.jpg").

The long answer is that the impeller blades, oriented as= they=20 are, is a
stable, wide operating band style impeller.  To use an= =20 aircraft analogy,
this pump has a positive static margin.

Some= thing=20 that's interesting about pumps such as this is that they can
squeeze = more=20 efficiency out of the impeller by rotating the blade on the=20
impeller.  The downside to increasing the efficiency in this man= ner=20 is
that the operating range is reduced and, similar to reducing the s= tatic=20
margin in an airplane, is that you pay for it in stability.  If = a=20 pump
of this design were "flying" at its neutral point, the blades wo= uld=20 be
oriented radially from the axis of rotation.  Continuing with= the=20
airplane analogy, if the pump were "flying" with negative static marg= in,=20
but also at its most potentially efficient, but also most likely to= =20
cavitate and go unstable, the blades would be mirror-imaged from the= =20
orientation they're in now, but still rotating in the same=20 direction.

I'm sure what I've explained is clear as mud,=20 yes?

Anyway, hope it helps.

Regards,

Cedric=20 Gould

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