Vivian Meazza wrote:
The attached diff models the output of a gear-driven
supercharger. I've used a 3rd order polynomial which matches the few
examples I have been able to find, giving near-linear output up to the
max-power rpm of the engine, with a little tail-off below this point,
and a
Andy Ross wrote:
Vivian Meazza wrote:
The attached diff models the output of a gear-driven
supercharger. I've used a 3rd order polynomial which matches the few
examples I have been able to find, giving near-linear output up to the
max-power rpm of the engine, with a little tail-off below
Andy Ross wrote:
Vivian Meazza wrote:
However (and there's always a however), I can't land the
thing. Closing the throttle and pulling back the propeller pitch
control doesn't reduce the power enough. I reasoned that there was too
much boost with the throttle closed, (currently set at
Andy Ross wrote:
I wrote:
Jim Wilson wrote:
4) Fixed rpm/power numbers under the prop tags. They need to be
scaled back according to the gear ratio. Someone with a better
understanding of mech engineering might be able to explain why the
BHP on the prop shaft is
Vivian Meazza wrote:
However (and there's always a however), I can't land the
thing. Closing the throttle and pulling back the propeller pitch
control doesn't reduce the power enough. I reasoned that there was too
much boost with the throttle closed, (currently set at 10%,
AFAICS). 10% of the
Andy Ross wrote
Vivian Meazza wrote:
However (and there's always a however), I can't land the
thing. Closing the throttle and pulling back the propeller pitch
control doesn't reduce the power enough. I reasoned that there was too
much boost with the throttle closed, (currently set at
On Thu, 7 Apr 2005 19:16:08 +0100, Vivian wrote in message
[EMAIL PROTECTED]:
Andy Ross wrote
Vivian Meazza wrote:
However (and there's always a however), I can't land the
thing. Closing the throttle and pulling back the propeller pitch
control doesn't reduce the power enough. I
On Thu, 7 Apr 2005 21:37:31 +0200, Arnt wrote in message
[EMAIL PROTECTED]:
On Thu, 7 Apr 2005 19:16:08 +0100, Vivian wrote in message
[EMAIL PROTECTED]:
Andy Ross wrote
Working on it right now. BTW the Merlin had a Roots type
displacement compressor.
..apologies all, I hit the
Arnt Karlsen wrote
Andy Ross wrote
Vivian Meazza wrote:
However (and there's always a however), I can't land the
thing. Closing the throttle and pulling back the propeller pitch
control doesn't reduce the power enough. I reasoned that there was
too much boost with the
I wrote:
Jim Wilson wrote:
4) Fixed rpm/power numbers under the prop tags. They need to be
scaled back according to the gear ratio. Someone with a better
understanding of mech engineering might be able to explain why the
BHP on the prop shaft is reduced by a factor of 0.35 when
On Saturday 19 March 2005 23:55, Josh Babcock wrote:
[snip...]
Is the sweep supposed to be the LE or the .25% chord?
Josh
The sweep in YASim is measured at the chord mid-point.
At least that's what I've been using:)
It corresponds with the wing location definition and I vaguely
remember
Lee Elliott wrote:
On Saturday 19 March 2005 23:55, Josh Babcock wrote:
[snip...]
Is the sweep supposed to be the LE or the .25% chord?
Josh
The sweep in YASim is measured at the chord mid-point.
At least that's what I've been using:)
It corresponds with the wing location definition and I vaguely
From: Andy Ross
snip
FWIW, I also took the opportunity to re-visit the P-51D configuration
that I promised (long ago) to hack at. Attached is a version that
snip
Also, there is a syntax fix: the piston-engine tag should be a
subtag of the propeller tag. Putting it immediately after the
Jim Wilson wrote:
From: Andy Ross
snip
FWIW, I also took the opportunity to re-visit the P-51D configuration
that I promised (long ago) to hack at. Attached is a version that
snip
Also, there is a syntax fix: the piston-engine tag should be a
subtag of the propeller tag. Putting
From: Curtis L. Olson
Note that the speed you give to YAsim is true speed, not indicated
airspeed. This can make a big difference up at altitude. Also, you
have to pay close attention to the weight YAsim solves at versus the
weight you test fly at.
Hi Curt,
Yes, I know. The test
Jim Wilson wrote:
4) Fixed rpm/power numbers under the prop tags. They need to be
scaled back according to the gear ratio. Someone with a better
understanding of mech engineering might be able to explain why the
BHP on the prop shaft is reduced by a factor of 0.35 when that's
discussions
flightgear-devel@flightgear.org
To: FlightGear developers discussions flightgear-devel@flightgear.org
Subject: Re: [Flightgear-devel] Help with B-29
Date: Sat, 19 Mar 2005 06:24:26 +0100
On Fri, 18 Mar 2005 11:14:45 -0800, Andy wrote in message
[EMAIL PROTECTED]:
Josh Babcock wrote:
OK
Arnt Karlsen wrote:
..what had me wondering is the eng-rpm in the turbine-engine section,
where these word of wisdom appears: ;o)
And what would you propose? Turbine RPM is almost never quoted in
real units, but in percentages. Where is appropriate, the
documentation tells you to specify
Jim Wilson wrote:
From: Josh Babcock
snip
Yeah, I'm still messing around and I don't really understand what I'm doing.
The .35 gear ratio came straight out of the POH, and I think I recall seeing a
cutaway photo of this engine with a gearbox behind the propeller. The engine
rpms should be
Yeah, I have been reviewing this, and I think I understand how the definition
works. I'm getting pretty much the same numbers based on the 2900 and .35
which
I got out of the POH and several internet sources on the cyclone engines. I
have
a more appropriate yasim file now, but I still
Jim Wilson wrote:
Yeah, I have been reviewing this, and I think I understand how the definition
works. I'm getting pretty much the same numbers based on the 2900 and .35 which
I got out of the POH and several internet sources on the cyclone engines. I have
a more appropriate yasim file now, but
Jim Wilson wrote:
Yeah, I have been reviewing this, and I think I understand how the definition
works. I'm getting pretty much the same numbers based on the 2900 and .35 which
I got out of the POH and several internet sources on the cyclone engines. I have
a more appropriate yasim file now, but
Josh Babcock wrote:
Jim Wilson wrote:
Yeah, I have been reviewing this, and I think I understand how the
definition works. I'm getting pretty much the same numbers based on
the 2900 and .35 which I got out of the POH and several internet
sources on the cyclone engines. I have a more appropriate
Josh Babcock wrote:
Josh Babcock wrote:
Jim Wilson wrote:
Yeah, I have been reviewing this, and I think I understand how the
definition works. I'm getting pretty much the same numbers based on
the 2900 and .35 which I got out of the POH and several internet
sources on the cyclone engines. I
On Sat, 19 Mar 2005 07:45:07 -0800, Andy wrote in message
[EMAIL PROTECTED]:
Arnt Karlsen wrote:
..what had me wondering is the eng-rpm in the turbine-engine
section, where these word of wisdom appears: ;o)
And what would you propose? Turbine RPM is almost never quoted in
real units,
Josh Babcock wrote:
Jim Wilson wrote:
It means you've found a bug in the solver. I don't recall it doing
that. Maybe it is just a missing sanity check. Post what you have.
It looks like it's only getting one line into the file. I'll muck with the
first few lines and see what I can do.
Josh Babcock wrote:
OK, here's the file:
http://home.comcast.net/~jrbabcock/superfort/b29-yasim.xml
Some random notes, before I start running it:
The inbord and outboard engines don't match. Your inbord ones are
defined to produce 2200 HP at 1000 RPM (which is *monster* engine),
while your
Andy Ross wrote:
Josh Babcock wrote:
OK, here's the file:
http://home.comcast.net/~jrbabcock/superfort/b29-yasim.xml
Some random notes, before I start running it:
The inbord and outboard engines don't match. Your inbord ones are
defined to produce 2200 HP at 1000 RPM (which is *monster* engine),
Josh Babcock wrote:
Andy Ross wrote:
Josh Babcock wrote:
OK, here's the file:
http://home.comcast.net/~jrbabcock/superfort/b29-yasim.xml
Some random notes, before I start running it:
The inbord and outboard engines don't match. Your inbord ones are
defined to produce 2200 HP at 1000 RPM (which
Arnt Karlsen wrote:
..very good question! Comparing the notes on piston engines and
turboprops, is confusing, is the eng-rpm the prop shaft rpm?
[...]
..we're back to checking the source, to see what Andy meant here. ;o)
Uh, the lines in the README.yasim document read, exactly:
On Fri, 18 Mar 2005 15:21:35 -0800, Andy wrote in message
[EMAIL PROTECTED]:
Arnt Karlsen wrote:
..very good question! Comparing the notes on piston engines and
turboprops, is confusing, is the eng-rpm the prop shaft rpm?
[...]
..we're back to checking the source, to see what Andy
On Fri, 18 Mar 2005 11:14:45 -0800, Andy wrote in message
[EMAIL PROTECTED]:
Josh Babcock wrote:
OK, here's the file:
http://home.comcast.net/~jrbabcock/superfort/b29-yasim.xml
Some random notes, before I start running it:
The inbord and outboard engines don't match. Your inbord ones
On Tue, 15 Mar 2005 21:24:00 -0600, Dave wrote in message
[EMAIL PROTECTED]:
FG_PROPELLER NAME=prop
IXX 53.2729
DIAMETER 199.2
NUMBLADES 4
GEARRATIO 2.3
..ahem: 35/100 for the R-3350's in the B-29'ers.
..the R-3350 was built with several different gear ratios, so
Arnt Karlsen wrote:
On Tue, 15 Mar 2005 21:24:00 -0600, Dave wrote in message
[EMAIL PROTECTED]:
FG_PROPELLER NAME=prop
IXX 53.2729
DIAMETER 199.2
NUMBLADES 4
GEARRATIO 2.3
..ahem: 35/100 for the R-3350's in the B-29'ers.
..the R-3350 was built with several different gear
From: Josh Babcock
Right, thanks. It does say .35 in the POH.
Now I have a YASim engine question. I'm trying to rebuild the YASim file
from
scratch to see if I can get it to work. In README.yasim, the line:
eng-rpm: The engine RPM at which eng-power is developed
Jim Wilson wrote:
From: Josh Babcock
Right, thanks. It does say .35 in the POH.
Now I have a YASim engine question. I'm trying to rebuild the YASim file from
scratch to see if I can get it to work. In README.yasim, the line:
eng-rpm: The engine RPM at which eng-power is
From: Josh Babcock
OK, I get it, I misunderstood the prop RPM settings and got thoroughly
confused.
The answer to my question was actually on the previous line of the README.
Now, what does it mean if yasim sits there for 15 or more minutes at 98% CPU
utilization? That's what's
Jim Wilson wrote:
From: Josh Babcock
OK, I get it, I misunderstood the prop RPM settings and got thoroughly confused.
The answer to my question was actually on the previous line of the README.
Now, what does it mean if yasim sits there for 15 or more minutes at 98% CPU
utilization? That's
On Thu, 17 Mar 2005 20:46:32 -0500, Josh wrote in message
[EMAIL PROTECTED]:
Arnt Karlsen wrote:
On Tue, 15 Mar 2005 21:24:00 -0600, Dave wrote in message
[EMAIL PROTECTED]:
FG_PROPELLER NAME=prop
IXX 53.2729
DIAMETER 199.2
NUMBLADES 4
GEARRATIO 2.3
On Thu, 17 Mar 2005 21:33:34 -0500, Jim wrote in message
[EMAIL PROTECTED]:
From: Josh Babcock
Right, thanks. It does say .35 in the POH.
Now I have a YASim engine question. I'm trying to rebuild the YASim
file from scratch to see if I can get it to work. In README.yasim,
the
Josh Babcock wrote:
As for the directory, it is Engines, but that doesn't matter, I tried it
both ways and it pretty much does the same thing. I just took a closer
look at this. I had misread the strace before. Here's what I found that
it's doing:
This might be a silly question, but are you
Josh Babcock wrote:
As for the directory, it is Engines, but that doesn't matter, I tried it
both ways and it pretty much does the same thing. I just took a closer
look at this. I had misread the strace before. Here's what I found that
it's doing:
This might be a silly question, but
Ampere K. Hardraade wrote:
On March 15, 2005 07:27 am, Josh Babcock wrote:
I abandoned the idea of using JSBSim mostly though because I can't find any
polar data on the superfort wing.
I think DATCOM+can give you the data that you want.
Ampere
___
Jon Berndt wrote:
Yeah, I actually took a look at that. I have a handle on how to do the XML, I
just don't have the expertise to make the actual sound files. The DC3 engine
sounds are nice, but they don't quite have that throaty sound that you get from
an 18 cyl radial. I found a few
Jon Berndt wrote:
Yeah, I actually took a look at that. I have a handle on how to do the XML, I
just don't have the expertise to make the actual sound files. The DC3 engine
sounds are nice, but they don't quite have that throaty sound that you get from
an 18 cyl radial. I found a few
open(/usr/local/share/FlightGear/data/Aircraft/b29/Engine/R-3350.xml,
The directory should be plural, Engines. Maybe that will fix it.
Also, this prop config will give you better thrust. Aero-Matic's prop
generator needs some work.
xml version=1.0?
!-- Generated by Aero-Matic v 0.7, with
Dave Culp wrote:
open(/usr/local/share/FlightGear/data/Aircraft/b29/Engine/R-3350.xml,
The directory should be plural, Engines. Maybe that will fix it.
Also, this prop config will give you better thrust. Aero-Matic's prop
generator needs some work.
[snip]
Dave,
Thanks for the prop file. I'll
Josh Babcock wrote:
OK, so I've been slowly working on this:
http://home.comcast.net/~jrbabcock/superfort/ for quite some time now.
I planned on getting it into CVS once it had a reasonable start for a
flight model. My problem is that I apparently am genetically incapable
of getting a YASim
Erik Hofman wrote:
Josh Babcock wrote:
OK, so I've been slowly working on this:
http://home.comcast.net/~jrbabcock/superfort/ for quite some time
now. I planned on getting it into CVS once it had a reasonable start
for a flight model. My problem is that I apparently am genetically
incapable
Yeah, I actually took a look at that. I have a handle on how to do the XML, I
just don't have the expertise to make the actual sound files. The DC3 engine
sounds are nice, but they don't quite have that throaty sound that you get
from
an 18 cyl radial. I found a few recordings, but they
Josh Babcock wrote:
My problem is that I apparently am genetically incapable of
getting a YASim config to converge.
XML file? Output?
Andy
___
Flightgear-devel mailing list
Flightgear-devel@flightgear.org
OK, so I've been slowly working on this:
http://home.comcast.net/~jrbabcock/superfort/ for quite some time now. I
planned on getting it into CVS once it had a reasonable start for a flight
model. My problem is that I apparently am genetically incapable of getting a
YASim config to converge.
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