|
|
Hi Bobby
Thanks, I had the same thought yesterday. Introduced a further 15 in2 of airflow to cowl.
I must get on and instrument the cowl for pressures.
Thanks Lynn.
What kind of power difference might we see between say oil of 180F and 200F
Does oil temp also effects fuel economy?
I need to do further testing at higher airs speeds and trying to understand the tradeoffs between approx power/eccon cost if we were to only get down to 200F.
I had a Starmazda paper that stated that they target 200F.
Also any feedback on how to fly the engine would be appreciated by my test pilot friend who is doing the testing.
He is trying to get a handle on what rpm, map, prop pitch settings to use for the various flight regimes.
The prop is elect variable but not auto/constant speed.
For take off we are just winding in pitch (a human governor) to keep RPM at ~7300 and 120KIAS climb.
Now I’m guessing that we’ll eventually experiment with best rpm/blade pitch/map that gives best efficiency, but before then can you guys provide any wisdom?
What RPM might you target after initial climb?
As always, really appreciate the feedback.
Cheers
Steve Izett
> On 5 Nov 2019, at 3:21 am, lehanover lehanover@aol.com <flyrotary@lancaironline.net> wrote:
>
> The oil temp tracks the power output. Hotter rotor means hotter oil. Not a solid connection to water temps but some. Oil temps above 160 degrees cost power.
> Lynn E. Hanover
>
> In a message dated 11/4/2019 9:28:29 AM Eastern Standard Time, flyrotary@lancaironline.net writes:
>
> Steve,
>
> If all your exchangers dump into the cowl then the increased flow / pressure through the coolant exchangers may be limiting air flow through the oil cooler.
>
> Bobby
>
> -----Original Message-----
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
> Sent: Sunday, November 03, 2019 3:42 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Update on Glasair Cooling in Phase #1
>
> Sorry Matt, I just realised I hadn’t mentioned the actual oil temps.
> Highest in climb were 114C (237F) settling back to 110C this is 10C higher than previous flight?? OAT was up 4C ~7F
> I would have expected a symbiotic relationship between oil and water temps. Lower coolant yielding lower oil temps.
> This is troubling me, Prior to this flight I noticed oil level down on the stick. Its always been very consistently full with no signs of leaks etc. (Standard Renesis pan)
> It’s running Mobile 1 and measuring the oil entering the engine after cooler and filter.
>
> Steve
>
> > On 3 Nov 2019, at 11:35 pm, Matt Boiteau mattboiteau@gmail.com <flyrotary@lancaironline.net> wrote:
> >
> > Coolant looks great. Are you running a t-stat?
> > What are the oil temps when you say "high"? Synthetic? Weight? Oil pan or inlet temp location?
> >
> > This is my opinion, with synthetic 20W50 at oil pain temps, I'd be okay during the climb with 240F and hopefully after some air speed it drops down under 220F.
> >
> > I do agree you might have to open up to 100mm (4 inch) for oil cooler.
> >
> > - Matt Boiteau
> >> On 2019-11-03 8:31:47 AM, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
> >>
> >> Hi there people
> >>
> >> Over the past month I have updated the cooling system of the Glasair Super II RG in order to continue our phase 1 testing.
> >>
> >> The previous setup had 540in3 two pass behind the ~20in2 unmodified right cheek inlet.
> >> We hadn’t included the left cheek as it was so difficult to get the air across to the right hand side diffuser.
> >> The Oil is 250in3 behind a 8in2 under spinner inlet.
> >> Initial testing was marginal with OAT below 20C (68F)
> >> So having established that cooling was rather marginal above 68F I went for the planned upgrade path which included
> >> installing a secondary bike radiator of 130in3 plumbed into the heater circuit behind the ~15in2 left cheek inlet.
> >> The diffuser was designed to hopefully be more efficient in a climb configuration.
> >> So the total radiators frontal area has been increased by 50% while the air in has increased 75%.
> >> The unknown is that being in the heater circuit we don't know the total flow through the secondary rad compared with the primary rad.
> >>
> >> Testing on the ground yield an approx 15-20C drop in coolant after 30mins of 1800rpm idle.
> >>
> >> Flight Testing Results the next day: OAT 21C (70F)
> >> Coolant Temps max’d on climb at 93C (200F) down 15C on highest Flight 3 climb temp with a 4C higher OAT.
> >> Coolant Temps dropped to 83C (181F) as speed got to 147 KIAS (Cruise is published as 192 KIAS but we haven’t expanded the envelope to date)
> >> I’m very pleased with this result.
> >>
> >> Oil Temps are high. I would much prefer them below 80C (176F)
> >> I’ll be interested to see what oil temp does as speed rises, but my hunch is it needs more air (increase air to oil cooler from a diameter of 77mm to 100mm)
> >>
> >> Slow Speed Tests:
> >> Vs Clean Stall is at 67 KIAS row 2011 (Glasair claims 70 Knots at Gross)
> >> Vso Full Flap Stall is at 57 KIAS row 2062 & 2083 (Glasair claims 59 Knots at Gross)
> >>
> >> Cheers
> >>
> >> Steve Izett
> >> Perth Western Australia
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> --
> >> 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
|
|