X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) From: "Charlie England ceengland7@gmail.com" Received: from mail-il1-f173.google.com ([209.85.166.173] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 967510 for flyrotary@lancaironline.net; Fri, 20 Nov 2020 21:01:54 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.166.173; envelope-from=ceengland7@gmail.com Received: by mail-il1-f173.google.com with SMTP id u3so526189iln.1 for ; Fri, 20 Nov 2020 18:01:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language; bh=rh9kj+xgmRaKnIcWWYU6LW6OOXbkmtPGg4Hx4irX9/Q=; b=evOgh5uZlDPPEFmDU5r2JPtkvLK8IDQddx2a+Yg09VwNz0ro7O3qT8f76yrgIQu5l6 VVv8jUxzi4X+crp3NbSH/Bbj5lyfIFjA5nLyXOcgdiukZBnbMuNbhYmJf4zn5P+drMR6 Apf781wDtbl6EV/U/QPkzeYJWYvcuLKizblJzYLH2wRwfXWiiq6qOk9tw5Tqnw5RLFqJ nZzrc5fk07b14LQECJAMtDavFB2QTM0X3PoLfF9StUuAtv7M6sVwRDA8w+zqkzoJ3w5f /TnBX0ostcF+hn/2v39Qm7BMDUpxMAmCEWu+M2kdHIHBpOz071gkYiDzabR1ZC8an+YA 2v8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=rh9kj+xgmRaKnIcWWYU6LW6OOXbkmtPGg4Hx4irX9/Q=; b=CRm/WPrjWHEVbf3Gp+c/QN5yAUu1btV01q1DtQlXNn7oojp1xHG6SqsbTrYO7zCwbq K/oYpwSoBIdzODDatbbhVzKoKY59wy8fPDrI+aPQhzQqiCoJgvpMTqwh4MwoLkrE5t5t HG+rYpgsWRRkdt4ZP0roN+OfX4wE64pBKGBceBKxsMqF15wtRTqexIJ6qCzOwniPWkU+ 4qnHEfc7lwMp1FlnKKD8ogrB8LxCtaVMAzxhj0tQzCdM3sJ9EN+fhU+r6w7omcUyZDh2 BSIAgqwyCxhWaOJZq6V6ZcZOwNBJQc2EisgNFFP4c/Jt6I/pVQDkon1aVTerun7MTkHV 0nMw== X-Gm-Message-State: AOAM530ieZnl89bazT81hIMPsWfMAKwKw8Tn/lkQf9Xsc6qZUPbZAwSD 4ykmvQIaFM1BlsBbKM6WPAfswLlsnvs= X-Google-Smtp-Source: ABdhPJwvnpwyI3F6w7O+qkSZd2cnaOLBb9ESyyLlDx2MGZTvnDcEejlS4UwwMS9jzuOwmPQnkAsnuQ== X-Received: by 2002:a92:5f53:: with SMTP id t80mr24732288ilb.160.1605924097619; Fri, 20 Nov 2020 18:01:37 -0800 (PST) Return-Path: Received: from ?IPv6:::1? ([2607:fb90:99bb:5870:f9d4:52b4:5873:5b0]) by smtp.googlemail.com with ESMTPSA id u1sm2729319ilb.74.2020.11.20.18.01.35 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 20 Nov 2020 18:01:37 -0800 (PST) Subject: Re: [FlyRotary] Re: cooling modes To: Rotary motors in aircraft References: Message-ID: <2811cad0-95c6-ca45-da2b-f5ef13e2dfed@gmail.com> Date: Fri, 20 Nov 2020 20:03:13 -0600 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------E48518460A5A6AB9447D5A63" Content-Language: en-US X-Antivirus: Avast (VPS 201120-6, 11/20/2020), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. --------------E48518460A5A6AB9447D5A63 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Hi Bruce, The driver for me was trying to remain within the constraints of money, a stock cowl with minimum 'surgery', with nothing hanging out of the cowl. Another driver was due to 'standing on the shoulders of giants'; Tracy Crook does really light weight installations, and his calcs showed that at least in his RV4, he needed the weight of the heat exchangers to be up front, to keep CG in the right place. My FWF weighs almost exactly the same as an O-320, so for now, I'll keep the  wedge in place. Please be aware that my setup may not survive to the 2nd flight. :-) In retrospect, I might well have done the same as Steve mentioned, and at least try to tuck the rad into the space behind/below the engine and feed it with a duct up to the prop. Charlie On 11/20/2020 6:59 PM, Bruce Cosgrove bcosgrove@mac.com wrote: > Hi Steve, Charlie, Matt, Roy and others > I am in the process making up a  cooling system for a Tango 2 and was > also planning to use the wedge shaped diffuser design, however the > information that I have been reading from the homebuilt airplanes site > discussing alternate approaches with less drag and improved > efficiency? has me re thinking my design towards a belly mounted > radiator.  The comments under the heading Successful Auto Conversion > Trials, Tribulations and Tips, I found particularly interesting - in > particular input from Russell and RJ6ejGUY who both have devised > systems that are working well for them  Belly radiators may not be > everyones idea of how to proceed but I like the idea of relatively > unimpeded air flow and freeing up space in the cowling.  any feedback > would be much appreciated. > > Bruce > > On 21 November 2020 at 10:00:57, Stephen Izett stephen.izett@gmail.com > (flyrotary@lancaironline.net ) wrote: > >> Nice work Charlie. >> >> Steve >> >> > On 21 Nov 2020, at 6:50 am, Charlie England ceengland7@gmail.com >> wrote: >> > >> > My (untested in combat) version for my radiator looks similar, but >> because the inlet is offset, I had to use a turning vane to get flow >> into the lower front of the core. The outside doesn't give a good >> idea on how 'tight' the inner surface is. I had to use expanding foam >> to fill the inside, then re-shape, then glass over the foam. As I >> said, the back 1/4-1/3 of the diffuser tapers tightly to almost touch >> the core at the back. >> > >> > After observing both rotary and piston installations that work, I'm >> beginning to think that turning vanes may be the 'good enough' vs >> fighting for perfection in diffuser shape. My oil cooler core has a >> much more elaborate vane setup, driven by the very short duct length >> and even greater offset to the bottom edge of the core. >> > >> > Charlie >> > >> > >> > On 11/20/2020 4:22 PM, Stephen Izett stephen.izett@gmail.com wrote: >> >> Hi Roy >> >> >> >> Here is a photo of our Mocal 44 row oil cooler with diffuser. A >> K&M Streamline into a wedge. >> >> Not sure of the dimensions of hand. The Mocal web site will have >> specs so you could get a rough idea of size. >> >> I tested this one recently with a leaf blower approximating 100 >> knot air flow and in that test it was very even. >> >> >> >> Having said that, I tested our water radiator wedge diffuser when >> I built it years ago and had it reasonably even >> >> measuring pressures across the exit face, but now instrumenting it >> in flight its flow is vastly uneven. >> >> >> >> I have found that the flow is dependant not only on getting the >> diffuser shape right according to the various papers (eg. K&W, >> London, Oblique Flow Diffusers - Streamline ) >> >> But importantly the environment it ends up in. The papers share >> data for ideal conditions with for example unobstructed exit air paths. >> >> My thoughts now are that this has a significant impact on the >> performance and therefore the advantage of instrumenting in flight >> and reshaping for actual conditions. >> >> >> >> The data I collected yesterday of our H2O diffuser reveals that >> the air flow in various points across the face are very different. >> >> Simplified, if I average the pressures at the five points I >> measured, then comparatively the back is up 20%, the centre up 25% >> and the front down 60% from that average figure. >> >> I’m figuring a 20% difference is probably OK, but my front to >> back/middle difference of ~80% down in the front top of that radiator >> may hold significant room for improvement. >> >> Further, my data suggests that as IAS rises those differences are >> amplified. >> >> So I am now targeting the modifications for our worst case >> conditions of WOT sea level ~200hp and initial climb numbers of 115KIAS. >> >> >> >> Cheers. >> >> >> >> Steve Izett >> >> >> >> >> >> >> >>> On 21 Nov 2020, at 3:37 am, ROY GLENN rglenn14@sbcglobal.net >> wrote: >> >>> >> >>> Could some ne post a photo of their wedge shape and dimensions. >> >>> Thanks Roy >> >>> >> >>> -- >> >>> Homepage: http://www.flyrotary.com/ >> >>> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> >> >> > >> > >> > >> > >> > This email has been checked for viruses by Avast antivirus software. >> > www.avast.com >> > >> > >> > -- >> > Homepage: http://www.flyrotary.com/ >> > Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus --------------E48518460A5A6AB9447D5A63 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit
Hi Bruce,

The driver for me was trying to remain within the constraints of money, a stock cowl with minimum 'surgery', with nothing hanging out of the cowl. Another driver was due to 'standing on the shoulders of giants'; Tracy Crook does really light weight installations, and his calcs showed that at least in his RV4, he needed the weight of the heat exchangers to be up front, to keep CG in the right place. My FWF weighs almost exactly the same as an O-320, so for now, I'll keep the  wedge in place. Please be aware that my setup may not survive to the 2nd flight. :-)

In retrospect, I might well have done the same as Steve mentioned, and at least try to tuck the rad into the space behind/below the engine and feed it with a duct up to the prop.

Charlie

On 11/20/2020 6:59 PM, Bruce Cosgrove bcosgrove@mac.com wrote:
Hi Steve, Charlie, Matt, Roy and others
I am in the process making up a  cooling system for a Tango 2 and was also planning to use the wedge shaped diffuser design, however the information that I have been reading from the homebuilt airplanes site discussing alternate approaches with less drag and improved efficiency? has me re thinking my design towards a belly mounted radiator.  The comments under the heading Successful Auto Conversion Trials, Tribulations and Tips, I found particularly interesting - in particular input from Russell and RJ6ejGUY who both have devised systems that are working well for them  Belly radiators may not be everyones idea of how to proceed but I like the idea of relatively unimpeded air flow and freeing up space in the cowling.  any feedback would be much appreciated.

Bruce

On 21 November 2020 at 10:00:57, Stephen Izett stephen.izett@gmail.com (flyrotary@lancaironline.net) wrote:

Nice work Charlie.

Steve

> On 21 Nov 2020, at 6:50 am, Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:
>
> My (untested in combat) version for my radiator looks similar, but because the inlet is offset, I had to use a turning vane to get flow into the lower front of the core. The outside doesn't give a good idea on how 'tight' the inner surface is. I had to use expanding foam to fill the inside, then re-shape, then glass over the foam. As I said, the back 1/4-1/3 of the diffuser tapers tightly to almost touch the core at the back.
>
> After observing both rotary and piston installations that work, I'm beginning to think that turning vanes may be the 'good enough' vs fighting for perfection in diffuser shape. My oil cooler core has a much more elaborate vane setup, driven by the very short duct length and even greater offset to the bottom edge of the core.
>
> Charlie
>
>
> On 11/20/2020 4:22 PM, Stephen Izett stephen.izett@gmail.com wrote:
>> Hi Roy
>>
>> Here is a photo of our Mocal 44 row oil cooler with diffuser. A K&M Streamline into a wedge.
>> Not sure of the dimensions of hand. The Mocal web site will have specs so you could get a rough idea of size.
>> I tested this one recently with a leaf blower approximating 100 knot air flow and in that test it was very even.
>>
>> Having said that, I tested our water radiator wedge diffuser when I built it years ago and had it reasonably even
>> measuring pressures across the exit face, but now instrumenting it in flight its flow is vastly uneven.
>>
>> I have found that the flow is dependant not only on getting the diffuser shape right according to the various papers (eg. K&W, London, Oblique Flow Diffusers - Streamline )
>> But importantly the environment it ends up in. The papers share data for ideal conditions with for example unobstructed exit air paths.
>> My thoughts now are that this has a significant impact on the performance and therefore the advantage of instrumenting in flight and reshaping for actual conditions.
>>
>> The data I collected yesterday of our H2O diffuser reveals that the air flow in various points across the face are very different.
>> Simplified, if I average the pressures at the five points I measured, then comparatively the back is up 20%, the centre up 25% and the front down 60% from that average figure.
>> I’m figuring a 20% difference is probably OK, but my front to back/middle difference of ~80% down in the front top of that radiator may hold significant room for improvement.
>> Further, my data suggests that as IAS rises those differences are amplified.
>> So I am now targeting the modifications for our worst case conditions of WOT sea level ~200hp and initial climb numbers of 115KIAS.
>>
>> Cheers.
>>
>> Steve Izett
>>
>>
>>
>>> On 21 Nov 2020, at 3:37 am, ROY GLENN rglenn14@sbcglobal.net <flyrotary@lancaironline.net> wrote:
>>>
>>> Could some ne post a photo of their wedge shape and dimensions.
>>> Thanks Roy
>>>
>>> --
>>> Homepage: http://www.flyrotary.com/
>>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>
>
>
>
>
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