X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.2 cv=as3wMmRV c=1 sm=1 tr=0 a=aj5/eV7LgyRKFAqdCq+RMQ==:117 a=EI9QUpVSlqcA:10 a=2VWlnlWLIN4A:10 a=vdKS6djGr-IA:10 a=x7bEGLp0ZPQA:10 a=ocR9PWop10UA:10 a=PmhH1KkZReAA:10 a=Ia-xEzejAAAA:8 a=pGLkceISAAAA:8 a=k15QntoE1cHzgzeBXmkA:9 a=vmWHUXyfpHdVTjXm:21 a=viK7UTN18vo7oIyz:21 a=pILNOxqGKmIA:10 a=yOJN6MzYTztfUncmL3QA:9 a=3O2WA71HS5qqZnbr:21 a=_W_S_7VecoQA:10 a=frz4AuCg-hUA:10 a=Urk15JJjZg1Xo0ryW_k8:22 From: "Steven W. Boese SBoese@uwyo.edu" Received: from [104.47.41.104] (HELO NAM03-DM3-obe.outbound.protection.outlook.com) by logan.com (CommuniGate Pro SMTP 6.2.1) with ESMTPS id 10493352 for flyrotary@lancaironline.net; Sat, 30 Dec 2017 02:33:04 -0500 Received-SPF: none receiver=logan.com; client-ip=104.47.41.104; envelope-from=SBoese@uwyo.edu DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uwy.onmicrosoft.com; s=selector1-uwyo-edu; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=RyTCHFospOhp8CiiiI4Qerua2c4oNeX2Mzqri5ViSFA=; b=FslaIW8FRPe/fQSJ9VunHVa4xP9VZauV5u4ZA61Vd55p6/TkDMq54XB7FJLg7510Ec138dKUuPoD4OQxT7uUKZCifPNHN0Hnl8EzUvP0Q6LNKN24NKV1xbGALBMtBYi5ynefVihFfYEPrbkqLTbZbL7b6F/5SlAR6KS22KluyNA= Received: from CY1PR0501MB1546.namprd05.prod.outlook.com (10.161.161.144) by CY1PR0501MB1450.namprd05.prod.outlook.com (10.160.149.11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id 15.20.366.3; Sat, 30 Dec 2017 07:32:47 +0000 Received: from CY1PR0501MB1546.namprd05.prod.outlook.com ([10.161.161.144]) by CY1PR0501MB1546.namprd05.prod.outlook.com ([10.161.161.144]) with mapi id 15.20.0366.007; Sat, 30 Dec 2017 07:32:47 +0000 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Cooling Issues Thread-Topic: [FlyRotary] Re: Cooling Issues Thread-Index: AQHTgQ/Nup2ceglaJkaXirkmFC2h8qNbaJ+7 Date: Sat, 30 Dec 2017 07:32:47 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=SBoese@uwyo.edu; x-originating-ip: [69.146.88.60] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;CY1PR0501MB1450;7:BuIPBEQujuGH91counPh6n3vlVN0VHfdclUDqd5WOb0lx47R6GRoj3F4BLcZTh3hGCjzHtW485cAYJedHavA27Q/JXztUV0PznPitCkJIrZOI5a66ej6higdmqByNfm+SPFyYBi9uRyAvs/KuAU5S1NL8DXFpJJjW7yATqGCuH6C3I3/KeD3vbWckUu3djGUwF5QKARjj+J7BFpM4CidJMGMCZNmZlnvK/5KWsSeYJmZUsGFXoPg+G33fZ+BvTdC x-ms-exchange-antispam-srfa-diagnostics: SSOS; x-ms-office365-filtering-correlation-id: b3784ead-dc4c-4c22-a04a-08d54f578667 x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(4534020)(4602075)(4627115)(201703031133081)(201702281549075)(5600026)(4604075)(3008032)(2017052603307)(7153060);SRVR:CY1PR0501MB1450; x-ms-traffictypediagnostic: CY1PR0501MB1450: x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(17755550239193); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040470)(2401047)(5005006)(8121501046)(3002001)(10201501046)(3231023)(944501075)(93006095)(93001095)(6041268)(20161123560045)(20161123562045)(20161123558120)(201703131423095)(201702281529075)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123564045)(6072148)(201708071742011);SRVR:CY1PR0501MB1450;BCL:0;PCL:0;RULEID:(100000803101)(100110400095);SRVR:CY1PR0501MB1450; x-forefront-prvs: 05373A0663 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(376002)(39380400002)(366004)(346002)(39850400004)(396003)(199004)(189003)(19627405001)(2950100002)(75432002)(106356001)(76176011)(6916009)(14454004)(6606003)(7736002)(8936002)(81156014)(478600001)(8676002)(105586002)(66066001)(33656002)(72206003)(74316002)(25786009)(6246003)(102836004)(54896002)(2900100001)(77096006)(81166006)(7696005)(229853002)(80792005)(97736004)(3660700001)(6436002)(316002)(3280700002)(99286004)(6116002)(5660300001)(2906002)(53936002)(786003)(9686003)(53546011)(68736007)(86362001)(6506007)(3846002)(88552002)(55016002);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR0501MB1450;H:CY1PR0501MB1546.namprd05.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; received-spf: None (protection.outlook.com: uwyo.edu does not designate permitted sender hosts) x-microsoft-antispam-message-info: 3Ot3kdX3YgDYRUYy4M8+eTTUdTElk4htuR0yaiorUuGKzVgvEzMqDXEWLraz2sncaLzALhdvJppCDe1g80TbeQ== spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: multipart/alternative; boundary="_000_CY1PR0501MB1546E6A5DDFF0F6B4F5515B4B91A0CY1PR0501MB1546_" MIME-Version: 1.0 X-OriginatorOrg: uwyo.edu X-MS-Exchange-CrossTenant-Network-Message-Id: b3784ead-dc4c-4c22-a04a-08d54f578667 X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Dec 2017 07:32:47.7542 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: f9cdd7ad-825d-4601-8e9c-a325e02d52da X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR0501MB1450 --_000_CY1PR0501MB1546E6A5DDFF0F6B4F5515B4B91A0CY1PR0501MB1546_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Steve, The test stand load was a 3 blade Warp Drive HP prop. The engine-reduction= drive assembly was mounted such that it was free to rotate on an axis coll= inear with the engine eccentric shaft but the rotation was constrained by a= load cell. The load cell measured the torque which, along with the prop R= PM, allowed the HP to be calculated. The prop blast supplied the cooling air to the radiator and oil cooler duct= s. The pressure on each side of the heat exchanger core was measured using= piccolo tubes across the core. The piccolo tube holes were 1/16" dia at = a 1" spacing. The holes were oriented perpendicular to the air flow throug= h the core. Each piccolo tube was connected to one side of a differential = pressure transducer while the other side of the transducer was open to the = atmosphere. It would have been possible to measure the delta P directly us= ing just one differential pressure transducer for each core, but I was inte= rested in the absolute pressures as well as the delta P. The same setup was used in the plane to measure the pressure at the inlet s= ide of the core of GM AC evaporator cores used as radiators behind short du= cts with stock cowl nostril inlets. In flight, the pressure at the core fa= ce was about 80% of the pressure measured by the airframe pitot tube. With= an in flight pitot pressure of about 10 "H2O, the pressure in front of ea= ch radiator core was about 8 "H2O and the pressure inside the upper cowl (n= ot near the radiators or cowl outlet) was about 4 "H2O, all relative to the= airframe static source. During stationary run up with a prop RPM of 2400= , the pressure recovered at the left radiator core was about 1.8 "H2O while= the pressure at the right radiator core was about 1.5 "H2O. Overheating a= t ide or while taxiing was normally not a problem. Take off and climb cool= ing was marginal at OAT over 70 deg while cooling at cruise was good. I ha= ve since changed to a belly scoop system with much improved take off and cl= imb cooling. I don't know of a convention for expressing inlet area with respect to the = lip shape. An inlet duct divergent area change from 16.5 sq in to 27 sq in= in a short distance indicated the potential for air flow separation from t= he duct wall and turbulence in the duct at the air flow velocities likely t= o be generated in flight. From your additional description, this would not= seem to be a concern. Steve Boese RV6A, 1986 13B NA, RD1A, EC2 ________________________________ From: Rotary motors in aircraft on behalf of = Stephen Izett stephen.izett@gmail.com Sent: Friday, December 29, 2017 6:44 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Cooling Issues Hi Steve I took a moment and estimated the total duct scaled from the drawing as bei= ng about 18.5 in^2 (Prop Flange is I think 6 in) Then I have taken away 2 in^2 for feeding the coils/alternator. It=92s that 2 in^2 I=92ll redeem for water cooling and move the coiling air= for the coils/alternator. I just realised to that I should probably be feeding the coils and alternat= or from diffused (slowed) air and not from free stream air. I=92ve always measured from the inside minimum neck of the entry and not in= cluded the lips. What is the convention? You appear to have measured from the outside of the flange which I measure = to be about 27 inch^2. I=92ve wondered how effective the inlet area right against the prop spinner= will be at cruise. Steve --_000_CY1PR0501MB1546E6A5DDFF0F6B4F5515B4B91A0CY1PR0501MB1546_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

Steve,


The test stand load was a 3 blad= e Warp Drive HP prop.  The engine-reduction drive assembly was mounted= such that it was free to rotate on an axis collinear with the engine eccen= tric shaft but the rotation was constrained by a load cell.  The load cell measured the torque which, along with = the prop RPM, allowed the HP to be calculated.


The prop blast supplied the cool= ing air to the radiator and oil cooler ducts.  The pressure on each si= de of the heat exchanger core was measured using piccolo tubes across the c= ore.  The piccolo tube holes were 1/16" dia  at a 1" spacing.  The holes were oriented perpendicula= r to the air flow through the core.  Each piccolo tube was connected t= o one side of a differential pressure transducer while the other side of th= e transducer was open to the atmosphere.  It would have been possible to measure the delta P directly using just one differential = pressure transducer for each core, but I was interested in the absolute pre= ssures as well as the delta P.


The same setup was used in the p= lane to measure the pressure at the inlet side of the core of GM AC evapora= tor cores used as radiators behind short ducts with stock cowl nostril inle= ts.  In flight, the pressure at the core face was about 80% of the pressure measured by the airframe pitot tub= e.  With an in flight pitot pressure of about 10  "H2O, the = pressure in front of each radiator core was about 8 "H2O and the press= ure inside the upper cowl (not near the radiators or cowl outlet) was about 4 "H2O, all relative to the airframe static so= urce.  During stationary  run up with a prop RPM of 2400, the pre= ssure recovered at the left radiator core was about 1.8 "H2O while the= pressure at the right radiator core was about 1.5 "H2O.  Overheating at ide or while taxiing was normally not a problem.  Take= off and climb cooling was marginal at OAT over 70 deg while cooling at cru= ise was good.  I have since changed to a belly scoop system with much = improved take off and climb cooling.  


I don't know of a convention for= expressing inlet area with respect to the lip shape.  An inlet duct d= ivergent area change from 16.5 sq in to 27 sq in in a short distance indica= ted the potential for air flow separation from the duct wall and turbulence in the duct at the air flow velocities l= ikely to be generated in flight.  From your additional description, th= is would not seem to be a concern.


Steve Boese
RV6A, 1986 13B NA, RD1A, EC2



 

From: Rotary motors in airc= raft <flyrotary@lancaironline.net> on behalf of Stephen Izett stephen= .izett@gmail.com <flyrotary@lancaironline.net>
Sent: Friday, December 29, 2017 6:44 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Cooling Issues
 
Hi Steve

I took a moment and estimated the total duct scaled from the drawing as bei= ng about 18.5 in^2 (Prop Flange is I think 6 in)
Then I have taken away 2 in^2 for feeding the coils/alternator.
It=92s that 2 in^2 I=92ll redeem for water cooling and move the coiling air= for the coils/alternator.
I just realised to that I should probably be feeding the coils and alternat= or from diffused (slowed) air and not from free stream air.

I=92ve always measured from the inside minimum neck of the entry and not in= cluded the lips. What is the convention?
You appear to have measured from the outside of the flange which I measure = to be about 27 inch^2.

I=92ve wondered how effective the inlet area right against the prop spinner= will be at cruise.

Steve


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