|
That is is going to be awesome. What airframe is it going in?
Dave Leonard.
Cheers Dave. Will stick with the
turbo(s) then.
We are aiming for 350hp and we know
that can easily be cooled, but the engine guy is confident that
with the right ductwork then a reliable 700hp is possible - but I
suspect that the fuel burn would be horrific.
The rotary has essentially the same losses with
altitude as any engine. There are a lot more considerations
than just SL horseposer and weight but IMHO you will be
dissapointed with the performance of any engine at FL250 if you
do not have some sort of forced air induction. If you are going
to bother to go that high on a regular basis, you may as well
put on a turbo to really take advantage of the higher TAS that
otherwise will be out of reach.
I fly mine right up to 17.5K whenever I have a
reason to do so, but without the turbo it would take too long
to get there and there would be no net benifit. Normally
aspirated engines really suck above 10k.
Dave Leonard
A question
from me - considering we will be using a 4 rotor engine
which will produce around 350hp without a turbo at sea
level - is a turbo really needed for an aircraft that is
MTOW 2250
lbs
Flying to
FL250
or would a
4 rotor/350hp engine be sufficient even with the loss of
power of a normally aspirated engine at altitude? (which I
vaguely recall is less of a power drop for a rotary engine
than a piston engine).
Hi Neil,
I started with the stock turbo knowing
it wasnt quite rite for the job, but hey, its came
free with my engine. It performed pretty well but
only lasted about 100 hrs. Since then I have been
with various iterataions of the TO4 in a modified
stock turbine housing. Those have performed very well
but are not industructable. Prolonged periods at Peak
EGT will melt them too. I have over 600 hrs on my
curent turbo becuase I keep it either rich or lean of
peak and the TOT less than 890C.
I recall the exact size of my radiator,
20"x22"x3" rings a bell. It is all detailed in the
archives and on my website. (which is in dire need of
an update).
Dave Leonard
www.rotaryroster.net
Dave,
Still trying to get around
to fitting a turbo, possibly next lifetime the
way I am going. What turbo did you end up
fitting, and what size cooler? Neil.
I agree with Marc. A proper
single turbo will be more efficient, more
reliable, and much easier to install.
Sequential turbos are most helpful to
minimize turbo lag in automotive
applications. Stock one or two-piece apex
seals are plenty (even preferred) for modest
boost levels (up to 150 hp per rotor or so).
The rotary will not burn
less fuel than an 8 cyl aircraft engine at
the same output. It will burn more, but
not an excessive amount more.
Dave Leonard
That does not
sound to me like a suitable aircraft
configuration.
A single turbo would suffice, the
controller/wastegate would dial in the
boost needed to maintain SL pressure in
the manifold at any condition, there isn't
a reason to 'overboost' the engine. Too
complicated and unnecessary-especially all
the hot turbo piping could get very messy.
Is the engine builder using ceramic rotor
tip seals? Good idea for boosted engines.
MW
-----Original Message-----
From: Rotary motors in aircraft
Sent: Wednesday, September 04, 2019 2:00
AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: The ultimate
question...
Was just talking to the engine builder and
the answer to one question also answered
another -
The reason that the engine will have two
turbos is that they are set up
sequentially - the first one operates as a
turbo normaliser to 500 rpm above cruise
rpm. Once the throttle is opened past
that point for takeoff/climbout the second
turbo kicks in to more power.
That also explains the fuel efficiency at
cruise - only a small turbo is operating
to provide turbo normalisation. Hope this
makes sense!
On 4/09/2019 11:21 am, Kent Bedford kbedford@alphalink.com.au
wrote:
> Kind of strange how it worked out,
but when we made a small change to
> the design that gave a tangible
benefit we suddenly found ourselves
> with room for an extra 40 gallons on
top of what we already had - 90
> gallons should be enough for range to
be governed by bladder size
> instead of fuel tank size.
>
> On 4/09/2019 6:08 am, Charlie England
ceengland7@gmail.com
wrote:
>> On 9/3/2019 2:31 AM, Kent Bedford
kbedford@alphalink.com.au
wrote:
>>> ...if someone has an about
450hp four rotor + turbo engine with
>>> effective cooling, and
resolves the torsional vibration and
>>> resonance issues (which will
partly be resolved by having four
>>> rotors anyway), are there any
other foreseeable likely or possible
>>> issues that may need to be
overcome to successfully operate it with
>>> a good 500hp-rated PSRU like
a Ballistic or similar?
>>>
>> Figuring out where to put the
fuel, unless you're talking about a
>> time-to-climb record attempt or
Reno racer. Any usable a/c at that
>> power level may require your own
refinery.
>> Charlie
>>
>>
>> ---
>> This email has been checked for
viruses by Avast antivirus software.
>> https://www.avast.com/antivirus
>>
>>
>> --
>> 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
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
|
|