X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=PbaBeRpd c=1 sm=1 tr=0 a=QTHwUz1q9nAP9ujD9u6kvg==:117 a=x7bEGLp0ZPQA:10 a=oSMvVwY2MYMA:10 a=y4yBn9ojGxQA:10 a=3oc9M9_CAAAA:8 a=Ia-xEzejAAAA:8 a=pGLkceISAAAA:8 a=7g1VtSJxAAAA:8 a=9jKCV9uy-01_cke0hMsA:9 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=d46lUuF_AAAA:8 a=m-0lX6eQSD6V6Ca6Wn0A:9 a=ZM3BiJmxiafGeEko:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=grOzbf7U_OpcSX4AJOnl:22 a=6lK6DICRFWFJG_1PXtoD:22 From: "David Leonard wdleonard@gmail.com" Received: from mail-oi1-f176.google.com ([209.85.167.176] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 611167 for flyrotary@lancaironline.net; Thu, 06 Aug 2020 12:05:13 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.167.176; envelope-from=wdleonard@gmail.com Received: by mail-oi1-f176.google.com with SMTP id k4so43346399oik.2 for ; Thu, 06 Aug 2020 09:05:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=EqJgLnFEmfLYzs0YuBw3m2en4/qCQLNRVhlgMnwUfu4=; b=KoFHAIDKQjFuL48+yRa6UbHN3GisEzGyFrgi04E09+QDAW/NSogmqJUyqIR1QchLhv fqJtTXYOMFUQzL10OqVzWM4DcpW6jEfongW5B8TQwXgH7nV9OdKRIPBI51w6Zzy2zXtJ C3WqyZxuQNfT0pzMMxn+D22oGTb8IVTcTlndEjmPZY6Z4KcZ+RWfa69iEPzVT6VdtclW cOCTr9mLI1DHoydx94yeLnz2D/f2skjKKQOD8lmLR1Jl3PH8u/zF1b9PChACwEbbFxr3 E3s/wtCw5yKQkXlZeoiTzMFlkVGhJOTZgXshgREhQ+grmf8eu3g3Wt53FpO0+g7Nh+tB 8IMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=EqJgLnFEmfLYzs0YuBw3m2en4/qCQLNRVhlgMnwUfu4=; b=M8JNqbQ2l+HTEoTdiIOPGCT1SavwzIZXYBzhQ3cuoWMXpISN5vi9fgpvg7QFYB5zSe X7HAjCMN0AEI9xRPehC1yQi2r5iqKGPDCFQHSNRI7OmLc1b9PjHZAom1zD6iVrELtdP/ EVIKPBJCphBsOToO+k37xppO3EjPJK0KR77y4HKHUDCI5YYiO5mACKFYCy4YVsfmvTfj Zbt4zeD2mn9WfE77+roWej3pFYgL+PMuSgGXt6vZc8sED4b22NkaCEGz4FcTKRFpJxpq l5nppg6Ou7936hKBxmN+HE+g4P/nWYoRzdN65uV14M7cG7SyF3b7C/6wfu9ES0DWWyDv 2Ffw== X-Gm-Message-State: AOAM532BmA1HdrzStxnJaDc6uTNCC4ZOY5s5PfKsBqbnJD6kGX8EYWLv /M9nZEDM2s56DUfX/W0OzX+zIO1yJJsT70CgP1jebw== X-Google-Smtp-Source: ABdhPJxQcsEFtudEjM+oCdW5qL9TViQeNaxd1EFFeTWElsZeKSjOpP8CdJlOj+YrnvauqHaTJDuLErcPcZ0t6u2ZN60= X-Received: by 2002:aca:4ccd:: with SMTP id z196mr7275680oia.86.1596729896263; Thu, 06 Aug 2020 09:04:56 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: Date: Thu, 6 Aug 2020 09:04:44 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Testing best rpm power setting To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="00000000000044e5fa05ac37a68e" --00000000000044e5fa05ac37a68e Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable After re-reading your email, I think maybe you are thinking about the term 'best power' that we use in aircraft. That refers to a mixture setting with a given RPM. Power always goes up with RPM until the very end of the engine. If you are using the IVO prop, remember that the flex in that prop throws a wrench into the mix. Dave Leonard On Thu, Aug 6, 2020 at 8:36 AM argoldman@aol.com < flyrotary@lancaironline.net> wrote: > Hy Guy[image: Wink], > > It is possible that your initial blade angle is set too coarse. > > With a CS or Variable pitch prop, one of the purposes is to enable max TO > RPM at takeoff. One of the reasons that the RPM builds up after a few > seconds is that after you achieve some forward motion the angle of attack > to the blades changes enabling full RPM. > > There is another possibility, again relating to the prop and that is that > because of the pitch, the prop is actually stalling producing little lift > (thrust) until forward motion changes the angle of attack and it unstalls= . > This is accompanied by a rather strange sound coming from the prop until = it > unstalls. > > I had that problem with my dragonfly. (Midwest AE110R/ CS prop > (airmaster) warp drive blades) Initially when I tried it on an early > x-plane I thought that it was the program, however in real life it happen= ed > exactly as simulated. I solved that problem by slowly advancing the > throttle. > > > -----Original Message----- > From: Stephen Izett stephen.izett@gmail.com > To: Rotary motors in aircraft > Sent: Thu, Aug 6, 2020 9:58 am > Subject: [FlyRotary] Testing best rpm power setting > > Hi guys > > I=E2=80=99m wanting to inflight test for the best RPM for peak power of o= ur 4 port > Renesis with variable pitch prop (No constant speed control at present). > On Takeoff at Full Fine we hit 6900 after a few seconds and then rpm > builds to 7400 by 500 feet and 110 KIAS > I=E2=80=99m wondering if we are well past the peak torque and would be be= tter off > at a lower rpm. > > Am I right in thinking the following would use the aircraft as a Dyno to > establish rpm for best power? > > 1. Set up level flight (auto pilot) > 2. Maintain WOT and constant mixture (best power - say 0.9 Lambda - 13.2 > AFR) via Wideband O2 > 3. Vary RPM in 200rpm increments for 2 minutes each setting between 5600 > and 7200 by adjusting prop pitch > 4. Note Fuel Flow and IAS (Logged on Dynon Skyview) > > I=E2=80=99m thinking this would give me an indication of best RPM for hig= hest > power. > Our Inlet is just under 19=E2=80=9D long, measured from the side face of = the > engine. > So I=E2=80=99m thinking peak torque may be around 6400 rpm. > > Your insight would be appreciated. > Thanks > > Steve Izett > Renesis 4 port RD1C (2.85:1) Inflight Adjustable Prop > > > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > --00000000000044e5fa05ac37a68e Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
After re-reading your email, I think maybe you are th= inking about the term 'best power' that we use in aircraft.=C2=A0 T= hat refers to a mixture setting with a given RPM.=C2=A0 Power always goes u= p with RPM until the very end of the engine.

If yo= u are using the IVO prop, remember that the flex in that prop throws a wren= ch into the mix.

Dave Leonard

<= div class=3D"gmail_quote">
On Thu, Aug= 6, 2020 at 8:36 AM argoldman@aol.com<= /a> <flyrotary@lancaironl= ine.net> wrote:
Hy Guy3D"Wink",

It is possible that your initial blade angle is set too coarse.

With a CS or Variable pitch prop, one of the purposes is to enable max= TO RPM at takeoff. One of the reasons that the RPM builds up after a few s= econds is that after you achieve some forward motion the angle of attack to= the blades changes enabling full RPM.

There is another possibility, again relating to the prop and that is t= hat because of the pitch, the prop is actually stalling producing little li= ft (thrust) until forward motion changes the angle of attack and it unstall= s. This is accompanied by a rather strange sound coming from the prop until= it unstalls.

I=C2=A0 had that problem with my dragonfly. (Midwest AE110R/ CS prop (= airmaster)=C2=A0 warp drive blades) Initially when I tried it on an early x= -plane I thought that it was the program, however in real life it happened = exactly as simulated. I solved that problem by slowly advancing the throttl= e.


-----= Original Message-----
From: Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, Aug 6, 2020 9:58 am
Subject: [FlyRotary] Testing best rpm power setting

Hi guys

I=E2=80=99m wanting to inflight test for the best RPM for = peak power of our 4 port Renesis with variable pitch prop (No constant spee= d control at present).
On Takeoff at Full Fine we hit 6900 after a few seconds an= d then rpm builds to 7400 by 500 feet and 110 KIAS
I=E2=80=99m wondering if we are well past the peak torque = and would be better off at a lower rpm.

Am I right in thinking the following would use the aircraf= t as a Dyno to establish rpm for best power?

1. Set up level flight (auto pilot)
2. Maintain WOT and constant mixture (best power - say 0.9= Lambda - 13.2 AFR) via Wideband O2
3. Vary RPM in 200rpm increments for 2 minutes each settin= g between 5600 and 7200 by adjusting prop pitch
4. Note Fuel Flow and IAS (Logged on Dynon Skyview)

I=E2=80=99m thinking this would give me an indication of b= est RPM for highest power.
Our Inlet is just under 19=E2=80=9D long, measured from th= e side face of the engine.
So I=E2=80=99m thinking peak torque may be around=C2=A0 64= 00 rpm.

Your insight would be appreciated.
Thanks

Steve Izett
Renesis 4 port RD1C (2.85:1) Inflight Adjustable Prop






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Homepage:=C2=A0 http://www.flyrotary.com/
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