Re: [Flightgear-devel] Re: New turbo/supercharger code
Le samedi 25 juin 2005 à 13:53 -0400, Josh Babcock a écrit : > Gerard Robin wrote: > > Le samedi 25 juin 2005 à 13:16 -0400, Josh Babcock a écrit : > > > >>Vivian Meazza wrote: > >> > >>>Josh Babcock > >>> > >>> > >>> > >>>I have a nagging memory that the Wright Cyclone R-3500 was fitted with > >>>reduction gearing between the crankshaft and propeller, although I can't > >>>find any reference to it right now. Do you have any details of the ratio? > >>>It's needed to migrate to the new Yasim propeller definition. > >>> > >>>You could use the R-2600 ratio, I suppose: > >>> > >>>Propeller Reduction Gear Ration (crankshaft to propeller): 16:9 > >>> > >>>That comes from here: > >>> > >>>http://wrightpattjobs.wpafb.af.mil/museum/engines/eng42a.htm > >>> > >>>V. > >>> > >>> > >>> > >>> > > > > Only for the fun, and may be seriously i can try to calculate it with > > the help of the new aeromatic propeller, i have implemented it locally. > > I need: Engine RPM -- Propeller diameter (inch or feet) -- Engine power > > ( HP or KW without boost). > > > > > 2700 rpm > 16'7" (4 blades) > 2200 hp > > Josh > = The results, i notice the calculation gives 3 blades with 2200 HP Inputs: horsepower: 2200 pitch: variable max engine rpm: 2700 prop diameter (ft): 16.7 Outputs: max prop rpm:1123.53 gear ratio: 2.40 Cp0:0.059661 Ct0:0.051308 static thrust (lbs):3327.61 --> 54.2414 200.4 3 2.40 12 30 899 1124 Again with 2400 HP we get 4 blades (min rpm and max rpm are the same) Inputs: horsepower: 2400 pitch: variable max engine rpm: 2700 prop diameter (ft): 16.7 Outputs: max prop rpm:1123.53 gear ratio: 2.40 Cp0:0.065084 Ct0:0.055972 static thrust (lbs):3630.12 --> 72.3219 200.4 4 2.40 12 30 899 1124 I don't know if it will be useful. > > > -- Gerard ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: New turbo/supercharger code
Gerard Robin wrote: > Le samedi 25 juin 2005 à 13:16 -0400, Josh Babcock a écrit : > >>Vivian Meazza wrote: >> >>>Josh Babcock >>> >>> >>> >>>I have a nagging memory that the Wright Cyclone R-3500 was fitted with >>>reduction gearing between the crankshaft and propeller, although I can't >>>find any reference to it right now. Do you have any details of the ratio? >>>It's needed to migrate to the new Yasim propeller definition. >>> >>>You could use the R-2600 ratio, I suppose: >>> >>>Propeller Reduction Gear Ration (crankshaft to propeller): 16:9 >>> >>>That comes from here: >>> >>>http://wrightpattjobs.wpafb.af.mil/museum/engines/eng42a.htm >>> >>>V. >>> >>> >>> >>> > > Only for the fun, and may be seriously i can try to calculate it with > the help of the new aeromatic propeller, i have implemented it locally. > I need: Engine RPM -- Propeller diameter (inch or feet) -- Engine power > ( HP or KW without boost). > > 2700 rpm 16'7" (4 blades) 2200 hp Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: New turbo/supercharger code
Le samedi 25 juin 2005 à 13:16 -0400, Josh Babcock a écrit : > Vivian Meazza wrote: > > Josh Babcock > > > > > > > > I have a nagging memory that the Wright Cyclone R-3500 was fitted with > > reduction gearing between the crankshaft and propeller, although I can't > > find any reference to it right now. Do you have any details of the ratio? > > It's needed to migrate to the new Yasim propeller definition. > > > > You could use the R-2600 ratio, I suppose: > > > > Propeller Reduction Gear Ration (crankshaft to propeller): 16:9 > > > > That comes from here: > > > > http://wrightpattjobs.wpafb.af.mil/museum/engines/eng42a.htm > > > > V. > > > > > > > > Only for the fun, and may be seriously i can try to calculate it with the help of the new aeromatic propeller, i have implemented it locally. I need: Engine RPM -- Propeller diameter (inch or feet) -- Engine power ( HP or KW without boost). > -- Gerard ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: New turbo/supercharger code
Vivian Meazza wrote: > Josh Babcock > > >>Melchior FRANZ wrote: >> >>>* Josh Babcock -- Saturday 25 June 2005 00:26: >>> >>> Weekly updates at http://jrbabcock.home.comcast.net/flightgear/superfort >>> >>> >>>I committed this, as it looks very nice and even flies, and there was a >> >>kind >> >>>of consense that this should be in cvs. I have yet to be able to land >> >>it, >> >>>though. Always goes into a deadly spin if I turn ... (There's some ugly >>>garbage hanging on the right main landing gear, and both don't retract.) >>> >>>m. >>> >>> >> >>Hmm, the right one should retract. The ugly junk is for testing, and >>will go away. Right now the stall speed is unusually high, and stalls >>can get pretty violent. The turn indicator is by far the most important >>instrument right now. I have not had a chance to fix this. >> > > > I've been having a look at the yasim config files. There are some odd > entries. I've tried to do a little fixing up, but with no real success. I > think you need to go to the new propeller definitions. > > I have a nagging memory that the Wright Cyclone R-3500 was fitted with > reduction gearing between the crankshaft and propeller, although I can't > find any reference to it right now. Do you have any details of the ratio? > It's needed to migrate to the new Yasim propeller definition. > > You could use the R-2600 ratio, I suppose: > > Propeller Reduction Gear Ration (crankshaft to propeller): 16:9 > > That comes from here: > > http://wrightpattjobs.wpafb.af.mil/museum/engines/eng42a.htm > > V. > > > > ___ > Flightgear-devel mailing list > Flightgear-devel@flightgear.org > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > 2f585eeea02e2c79d7b1d8c4963bae2d > Yeah, they used 3350-23s originally. I know they are geared. The only references I have for that model engine state that it has a .355:1 gear ratio. Some later models had a .3475:1 ratio, but AFAIK none of them were ever used in the 29. Here's some references, none are what I would call really definitive. http://www.supercoolprops.com/ARTICLES/gwhitegearheads.htm http://www.sun-inet.or.jp/~ja2tko/eng/ok_b29.museum1.html http://definition-info.com/B-29.html Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Josh Babcock > > Melchior FRANZ wrote: > > * Josh Babcock -- Saturday 25 June 2005 00:26: > > > >>Weekly updates at http://jrbabcock.home.comcast.net/flightgear/superfort > > > > > > I committed this, as it looks very nice and even flies, and there was a > kind > > of consense that this should be in cvs. I have yet to be able to land > it, > > though. Always goes into a deadly spin if I turn ... (There's some ugly > > garbage hanging on the right main landing gear, and both don't retract.) > > > > m. > > > > > > Hmm, the right one should retract. The ugly junk is for testing, and > will go away. Right now the stall speed is unusually high, and stalls > can get pretty violent. The turn indicator is by far the most important > instrument right now. I have not had a chance to fix this. > I've been having a look at the yasim config files. There are some odd entries. I've tried to do a little fixing up, but with no real success. I think you need to go to the new propeller definitions. I have a nagging memory that the Wright Cyclone R-3500 was fitted with reduction gearing between the crankshaft and propeller, although I can't find any reference to it right now. Do you have any details of the ratio? It's needed to migrate to the new Yasim propeller definition. You could use the R-2600 ratio, I suppose: Propeller Reduction Gear Ration (crankshaft to propeller): 16:9 That comes from here: http://wrightpattjobs.wpafb.af.mil/museum/engines/eng42a.htm V. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Jon Berndt > > That all looks very good. Does your implementation of the Boost Control > just > > control the pressure, or does it act on the throttle as I understand was > the > > way it worked in the Merlin? In simulation terms the outcome is probably > the > > same. > > > > V. > > Hi, Vivian: > > That would be a question for Dave Luff, who wrote that engine model for > JSBSim. If I had > time I'd look at the FGPiston.cpp code, but I've got really limited time > today and > tomorrow; I'm getting the new JSBSim code integrated with FlightGear, > among other things > I've got to do. > > The last post I see from Dave was about 6 months ago on the JSBSim list. > Don't worry, it was only for interest. I can poke around in the code for myself. Thanks Vivian ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
> That all looks very good. Does your implementation of the Boost Control just > control the pressure, or does it act on the throttle as I understand was the > way it worked in the Merlin? In simulation terms the outcome is probably the > same. > > V. Hi, Vivian: That would be a question for Dave Luff, who wrote that engine model for JSBSim. If I had time I'd look at the FGPiston.cpp code, but I've got really limited time today and tomorrow; I'm getting the new JSBSim code integrated with FlightGear, among other things I've got to do. The last post I see from Dave was about 6 months ago on the JSBSim list. Jon ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: New turbo/supercharger code
Melchior FRANZ wrote: > * Josh Babcock -- Saturday 25 June 2005 00:26: > >>Weekly updates at http://jrbabcock.home.comcast.net/flightgear/superfort > > > I committed this, as it looks very nice and even flies, and there was a kind > of consense that this should be in cvs. I have yet to be able to land it, > though. Always goes into a deadly spin if I turn ... (There's some ugly > garbage hanging on the right main landing gear, and both don't retract.) > > m. > > ___ > Flightgear-devel mailing list > Flightgear-devel@flightgear.org > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > 2f585eeea02e2c79d7b1d8c4963bae2d > Hmm, the right one should retract. The ugly junk is for testing, and will go away. Right now the stall speed is unusually high, and stalls can get pretty violent. The turn indicator is by far the most important instrument right now. I have not had a chance to fix this. Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] Re: New turbo/supercharger code
* Josh Babcock -- Saturday 25 June 2005 00:26: > Weekly updates at http://jrbabcock.home.comcast.net/flightgear/superfort I committed this, as it looks very nice and even flies, and there was a kind of consense that this should be in cvs. I have yet to be able to land it, though. Always goes into a deadly spin if I turn ... (There's some ugly garbage hanging on the right main landing gear, and both don't retract.) m. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Jon Berndt > > > Thanks, > > My question could be a question to Jon, Dave, and any JSB specialist. > > I just wonder, about, the opportunity to get profit of your work for > > developments on the JSB branch. The properties should be the same on > > the global FG level. > > Both FDM ->YASim ->JSBSim with a different "philosophic" approach should > > give the same end results. > > > > > -- > > Gerard > > See the FGPiston.h file in JSBSim. See the constructor in FGPiston.cpp for > exact specification in the new XML format (documentation pending). Here is > some data on what can be specified: > > Models Dave Luff's Turbo/Supercharged Piston engine model. > Additional elements are required for a supercharged engine. These can > be > left off a non-supercharged engine, ie. the changes are all backward > compatible at present. > > - NUMBOOSTSPEEDS - zero (or not present) for a naturally-aspirated > engine, > either 1, 2 or 3 for a boosted engine. This corresponds to the > number of > supercharger speeds. Merlin XII had 1 speed, Merlin 61 had 2, a > late > Griffon engine apparently had 3. No known engine more than 3, > although > some German engines apparently had a continuously variable-speed > supercharger. > > - BOOSTOVERRIDE - whether the boost pressure control system (either a > boost > control valve for superchargers or wastegate for turbochargers) can > be > overriden by the pilot. During wartime this was commonly possible, > and > known as "War Emergency Power" by the Brits. 1 or 0 in the config > file. > This isn't implemented in the model yet though, there would need to > be > some way of getting the boost control cutout lever position (on or > off) > from FlightGear first. > > - The next items are all appended with either 1, 2 or 3 depending on > which > boost speed they refer to, eg RATEDBOOST1. The rated values seems > to have > been a common convention at the time to express the maximum > continuously > available power, and the conditions to attain that power. > > - RATEDBOOST[123] - the absolute rated boost above sea level ambient > for a > given boost speed, in psi. Eg the Merlin XII had a rated boost of > 9psi, > giving approximately 42inHg manifold pressure up to the rated > altitude. > > - RATEDALTITUDE[123] - The altitude up to which rated boost can be > maintained. Up to this altitude the boost is maintained constant > for a > given throttle position by the BCV or wastegate. Beyond this > altitude the > manifold pressure must drop, since the supercharger is now at > maximum > unregulated output. The actual pressure multiplier of the > supercharger > system is calculated at initialisation from this value. > > - RATEDPOWER[123] - The power developed at rated boost at rated > altitude at > rated rpm. > > - RATEDRPM[123] - The rpm at which rated power is developed. > > - TAKEOFFBOOST - Takeoff boost in psi above ambient. Many aircraft > had an > extra boost setting beyond rated boost, but not totally uncontrolled > as in > the already mentioned boost-control-cutout, typically attained by > pushing > the throttle past a mechanical 'gate' preventing its inadvertant > use. This > was typically used for takeoff, and emergency situations, generally > for > not more than five minutes. This is a change in the boost control > setting, not the actual supercharger speed, and so would only give > extra > power below the rated altitude. When TAKEOFFBOOST is specified in > the > config file (and is above RATEDBOOST1), then the throttle position > is > interpreted as: > > - 0 to 0.95 : idle manifold pressure to rated boost (where attainable) > - 0.96, 0.97, 0.98 : rated boost (where attainable). > - 0.99, 1.0 : takeoff boost (where attainable). > > A typical takeoff boost for an earlyish Merlin was about 12psi, > compared > with a rated boost of 9psi. > > It is quite possible that other boost control settings could have been > used > on some aircraft, or that takeoff/extra boost could have activated by > other > means than pushing the throttle full forward through a gate, but this > will > suffice for now. > > Note that MAXMP is still the non-boosted max manifold pressure even > for > boosted engines - effectively this is simply a measure of the pressure > drop > through the fully open throttle. > That all looks very good. Does your implementation of the Boost Control just control the pressure, or does it act on the throttle as I understand was the way it worked in the Merlin? In simulation terms the outcome is probably the same. V. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-dev
Re: [Flightgear-devel] Re: New turbo/supercharger code
Vivian Meazza wrote: > > The link doesn't work. I think it might be time to consider giving aircraft > designers cvs access for their own work. > Sorry. There was a typo in the index.html file. Fixed. > > > Looks as if the pilot could adjust the wastegate settings in flight thus > controlling the turbo output. This will need a bit more investigation in > YASim. You are doing the B29 in YASim? > Yes. The YASim definition is very alpha right now though. Flyable, but the numbers are all wrong. I was having trouble getting it to converge so I gave it a break for a while to work on the 3D model. Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Josh Babcock > Vivian Meazza wrote: > > Josh Babcock > > > > > > > >>>Right now I've only researched the RR Merlin in any detail. Enough for > >> > >>our > >> > >>>current range of supercharged models. I don't know if Josh Babcock > needs > >>>anything special for the B29. > >>> > >> > >>I had done some research on the R-3350s, but it was a while ago. I do > >>know that the turbos are controled by an amplified rheostat, which I > >>think controls the the waste gate. > >> > >>Josh > >> > > > > > > Yes, that would be logical. > > > > Unless you have any turbo output pressure v height data, then I would > expect > > that the standard wastegate will model this well enough. Was there any > form > > of override which you would like to model? > > > > Are we going to get out hands on this model soon? I think there are > quite a > > few people looking forward to it, I know I am. > > > Weekly updates at http://jrbabcock.home.comcast.net/flightgear/superfort > I think Gerard was going to be commiting this, I'll have to check and > see what's up. The link doesn't work. I think it might be time to consider giving aircraft designers cvs access for their own work. > I'm not sure if that main control qualifies as an override. It's just a > dial that goes from 0 to 10 with a small mechanical safety switch for > going higher than 8. The pilot was supposed to st it to different > numbers at different power conditions and phases of the mission. 9 and > 10 were for emergencies. Looks as if the pilot could adjust the wastegate settings in flight thus controlling the turbo output. This will need a bit more investigation in YASim. You are doing the B29 in YASim? V. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Le vendredi 24 juin 2005 à 18:13 -0500, Jon Berndt a écrit : > > Thanks, > > Both FDM ->YASim ->JSBSim with a different "philosophic" approach should > > give the same end results. > > > > > -- > > Gerard > > See the FGPiston.h file in JSBSim. See the constructor in FGPiston.cpp for > exact specification in the new XML format (documentation pending). Here is > some data on what can be specified: > > Models Dave Luff's Turbo/Supercharged Piston engine model. > Additional elements are required for a supercharged engine. These can be > left off a non-supercharged engine, ie. the changes are all backward > compatible at present. > > -.. > power below the rated altitude. When TAKEOFFBOOST is specified in the > config file (and is above RATEDBOOST1), then the throttle position is > interpreted as: > > - 0 to 0.95 : idle manifold pressure to rated boost (where attainable) > - 0.96, 0.97, 0.98 : rated boost (where attainable). > - 0.99, 1.0 : takeoff boost (where attainable). > > A typical takeoff boost for an earlyish Merlin was about 12psi, compared > with a rated boost of 9psi. > > It is quite possible that other boost control settings could have been > used > on some aircraft, or that takeoff/extra boost could have activated by > other > means than pushing the throttle full forward through a gate, but this will > suffice for now. > > Note that MAXMP is still the non-boosted max manifold pressure even for > boosted engines - effectively this is simply a measure of the pressure > drop > through the fully open throttle. > > Thank , that is exactly, what i was looking for (i did not understood how it could do with FG) I must go further into it, and see how to build the property relationship within the existing FG properties. -- Gerard ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
> Thanks, > My question could be a question to Jon, Dave, and any JSB specialist. > I just wonder, about, the opportunity to get profit of your work for > developments on the JSB branch. The properties should be the same on > the global FG level. > Both FDM ->YASim ->JSBSim with a different "philosophic" approach should > give the same end results. > > > -- > Gerard See the FGPiston.h file in JSBSim. See the constructor in FGPiston.cpp for exact specification in the new XML format (documentation pending). Here is some data on what can be specified: Models Dave Luff's Turbo/Supercharged Piston engine model. Additional elements are required for a supercharged engine. These can be left off a non-supercharged engine, ie. the changes are all backward compatible at present. - NUMBOOSTSPEEDS - zero (or not present) for a naturally-aspirated engine, either 1, 2 or 3 for a boosted engine. This corresponds to the number of supercharger speeds. Merlin XII had 1 speed, Merlin 61 had 2, a late Griffon engine apparently had 3. No known engine more than 3, although some German engines apparently had a continuously variable-speed supercharger. - BOOSTOVERRIDE - whether the boost pressure control system (either a boost control valve for superchargers or wastegate for turbochargers) can be overriden by the pilot. During wartime this was commonly possible, and known as "War Emergency Power" by the Brits. 1 or 0 in the config file. This isn't implemented in the model yet though, there would need to be some way of getting the boost control cutout lever position (on or off) from FlightGear first. - The next items are all appended with either 1, 2 or 3 depending on which boost speed they refer to, eg RATEDBOOST1. The rated values seems to have been a common convention at the time to express the maximum continuously available power, and the conditions to attain that power. - RATEDBOOST[123] - the absolute rated boost above sea level ambient for a given boost speed, in psi. Eg the Merlin XII had a rated boost of 9psi, giving approximately 42inHg manifold pressure up to the rated altitude. - RATEDALTITUDE[123] - The altitude up to which rated boost can be maintained. Up to this altitude the boost is maintained constant for a given throttle position by the BCV or wastegate. Beyond this altitude the manifold pressure must drop, since the supercharger is now at maximum unregulated output. The actual pressure multiplier of the supercharger system is calculated at initialisation from this value. - RATEDPOWER[123] - The power developed at rated boost at rated altitude at rated rpm. - RATEDRPM[123] - The rpm at which rated power is developed. - TAKEOFFBOOST - Takeoff boost in psi above ambient. Many aircraft had an extra boost setting beyond rated boost, but not totally uncontrolled as in the already mentioned boost-control-cutout, typically attained by pushing the throttle past a mechanical 'gate' preventing its inadvertant use. This was typically used for takeoff, and emergency situations, generally for not more than five minutes. This is a change in the boost control setting, not the actual supercharger speed, and so would only give extra power below the rated altitude. When TAKEOFFBOOST is specified in the config file (and is above RATEDBOOST1), then the throttle position is interpreted as: - 0 to 0.95 : idle manifold pressure to rated boost (where attainable) - 0.96, 0.97, 0.98 : rated boost (where attainable). - 0.99, 1.0 : takeoff boost (where attainable). A typical takeoff boost for an earlyish Merlin was about 12psi, compared with a rated boost of 9psi. It is quite possible that other boost control settings could have been used on some aircraft, or that takeoff/extra boost could have activated by other means than pushing the throttle full forward through a gate, but this will suffice for now. Note that MAXMP is still the non-boosted max manifold pressure even for boosted engines - effectively this is simply a measure of the pressure drop through the fully open throttle. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: New turbo/supercharger code
Vivian Meazza wrote: > Josh Babcock > > > >>>Right now I've only researched the RR Merlin in any detail. Enough for >> >>our >> >>>current range of supercharged models. I don't know if Josh Babcock needs >>>anything special for the B29. >>> >> >>I had done some research on the R-3350s, but it was a while ago. I do >>know that the turbos are controled by an amplified rheostat, which I >>think controls the the waste gate. >> >>Josh >> > > > Yes, that would be logical. > > Unless you have any turbo output pressure v height data, then I would expect > that the standard wastegate will model this well enough. Was there any form > of override which you would like to model? > > Are we going to get out hands on this model soon? I think there are quite a > few people looking forward to it, I know I am. > > V. > > > > ___ > Flightgear-devel mailing list > Flightgear-devel@flightgear.org > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > 2f585eeea02e2c79d7b1d8c4963bae2d > Weekly updates at http://jrbabcock.home.comcast.net/flightgear/superfort I think Gerard was going to be commiting this, I'll have to check and see what's up. I'm not sure if that main control qualifies as an override. It's just a dial that goes from 0 to 10 with a small mechanical safety switch for going higher than 8. The pilot was supposed to st it to different numbers at different power conditions and phases of the mission. 9 and 10 were for emergencies. Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Josh Babcock > > > > Right now I've only researched the RR Merlin in any detail. Enough for > our > > current range of supercharged models. I don't know if Josh Babcock needs > > anything special for the B29. > > > > I had done some research on the R-3350s, but it was a while ago. I do > know that the turbos are controled by an amplified rheostat, which I > think controls the the waste gate. > > Josh > Yes, that would be logical. Unless you have any turbo output pressure v height data, then I would expect that the standard wastegate will model this well enough. Was there any form of override which you would like to model? Are we going to get out hands on this model soon? I think there are quite a few people looking forward to it, I know I am. V. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: New turbo/supercharger code
Vivian Meazza wrote: > Gerard > > >>>With Melchior's valuable help I have developed a nasal simulation of the >>>Boost Control and Boost Control Cutout for the Hurricane. This should be >>>committed to cvs shortly. When a preset boost value is exceeded, the >> >>Boost >> >>>Control acts to reduce throttle opening. This action can be overridden >> >>by >> >>>the Boost Control Cutout which allows maximum boost. The output of the >> >>Boost >> >>>Control is smoothed by a low-pass filter selected by Melchior. You will >>>notice an overshoot and some lag if the throttle is opened quickly. >>> >>>To make it work a patch (for cvs/head) is required to YASim - attached. >> >>A >> >>>new attribute 'supercharger' has been added to the aircraft config file. >>>When this is true, the attribute 'wastegate' no longer controls the >>>supercharger output. If you want to try the update to the Hurricane, you >>>will need to apply this patch. It will not adversely affect any other >> >>YASim >> >>>model, so far as I can tell. >>> >>>Both the nasal and YASim patch are temporary; both will require >> >>reworking >> >>>when Andy comes up with his revision of YASim to include the new >>>supercharger code. >>> >>>Any testing would be welcome, although Melchior is doing his best to >> >>break >> >>>it already! In particular any feedback on any adverse effects on other >>>models would be good. >>> >>>Regards, >>> >>>Vivian >> >>Do we have the same project, on JSBSim ? >>What must be done for it ? > > > I'm not sure where the supercharger stuff is at on JSBSim. Certainly doesn't > have a Boost Control Cutout. I'm not working on it - I've only just begun to > understand YASim. One thing at a time :-). I'm not aware of any requirement > in JSBSim > > Right now I've only researched the RR Merlin in any detail. Enough for our > current range of supercharged models. I don't know if Josh Babcock needs > anything special for the B29. > > V. > > > > ___ > Flightgear-devel mailing list > Flightgear-devel@flightgear.org > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > 2f585eeea02e2c79d7b1d8c4963bae2d > I had done some research on the R-3350s, but it was a while ago. I do know that the turbos are controled by an amplified rheostat, which I think controls the the waste gate. Josh ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Le vendredi 24 juin 2005 à 15:41 +0100, Vivian Meazza a écrit : > Gerard > > > > With Melchior's valuable help I have developed a nasal simulation of the > > > Boost Control and Boost Control Cutout for the Hurricane. This should be > > > committed to cvs shortly. When a preset boost value is exceeded, the > > Boost > > > Control acts to reduce throttle opening. This action can be overridden > > by > > > the Boost Control Cutout which allows maximum boost. The output of the > > Boost > > > Control is smoothed by a low-pass filter selected by Melchior. You will > > > notice an overshoot and some lag if the throttle is opened quickly. > > > > > > To make it work a patch (for cvs/head) is required to YASim - attached. > > A > > > new attribute 'supercharger' has been added to the aircraft config file. > > > When this is true, the attribute 'wastegate' no longer controls the > > > supercharger output. If you want to try the update to the Hurricane, you > > > will need to apply this patch. It will not adversely affect any other > > YASim > > > model, so far as I can tell. > > > > > > Both the nasal and YASim patch are temporary; both will require > > reworking > > > when Andy comes up with his revision of YASim to include the new > > > supercharger code. > > > > > > Any testing would be welcome, although Melchior is doing his best to > > break > > > it already! In particular any feedback on any adverse effects on other > > > models would be good. > > > > > > Regards, > > > > > > Vivian > > > > Do we have the same project, on JSBSim ? > > What must be done for it ? > > I'm not sure where the supercharger stuff is at on JSBSim. Certainly doesn't > have a Boost Control Cutout. I'm not working on it - I've only just begun to > understand YASim. One thing at a time :-). I'm not aware of any requirement > in JSBSim > > Right now I've only researched the RR Merlin in any detail. Enough for our > current range of supercharged models. I don't know if Josh Babcock needs > anything special for the B29. > > V. > > > Thanks, My question could be a question to Jon, Dave, and any JSB specialist. I just wonder, about, the opportunity to get profit of your work for developments on the JSB branch. The properties should be the same on the global FG level. Both FDM ->YASim ->JSBSim with a different "philosophic" approach should give the same end results. > -- Gerard ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
Gerard > > With Melchior's valuable help I have developed a nasal simulation of the > > Boost Control and Boost Control Cutout for the Hurricane. This should be > > committed to cvs shortly. When a preset boost value is exceeded, the > Boost > > Control acts to reduce throttle opening. This action can be overridden > by > > the Boost Control Cutout which allows maximum boost. The output of the > Boost > > Control is smoothed by a low-pass filter selected by Melchior. You will > > notice an overshoot and some lag if the throttle is opened quickly. > > > > To make it work a patch (for cvs/head) is required to YASim - attached. > A > > new attribute 'supercharger' has been added to the aircraft config file. > > When this is true, the attribute 'wastegate' no longer controls the > > supercharger output. If you want to try the update to the Hurricane, you > > will need to apply this patch. It will not adversely affect any other > YASim > > model, so far as I can tell. > > > > Both the nasal and YASim patch are temporary; both will require > reworking > > when Andy comes up with his revision of YASim to include the new > > supercharger code. > > > > Any testing would be welcome, although Melchior is doing his best to > break > > it already! In particular any feedback on any adverse effects on other > > models would be good. > > > > Regards, > > > > Vivian > > Do we have the same project, on JSBSim ? > What must be done for it ? I'm not sure where the supercharger stuff is at on JSBSim. Certainly doesn't have a Boost Control Cutout. I'm not working on it - I've only just begun to understand YASim. One thing at a time :-). I'm not aware of any requirement in JSBSim Right now I've only researched the RR Merlin in any detail. Enough for our current range of supercharged models. I don't know if Josh Babcock needs anything special for the B29. V. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
> With Melchior's valuable help I have developed a nasal simulation of the > Boost Control and Boost Control Cutout for the Hurricane. This should be > committed to cvs shortly. When a preset boost value is exceeded, the Boost > Control acts to reduce throttle opening. This action can be overridden by > the Boost Control Cutout which allows maximum boost. The output of the Boost > Control is smoothed by a low-pass filter selected by Melchior. You will > notice an overshoot and some lag if the throttle is opened quickly. > > To make it work a patch (for cvs/head) is required to YASim - attached. A > new attribute 'supercharger' has been added to the aircraft config file. > When this is true, the attribute 'wastegate' no longer controls the > supercharger output. If you want to try the update to the Hurricane, you > will need to apply this patch. It will not adversely affect any other YASim > model, so far as I can tell. > > Both the nasal and YASim patch are temporary; both will require reworking > when Andy comes up with his revision of YASim to include the new > supercharger code. > > Any testing would be welcome, although Melchior is doing his best to break > it already! In particular any feedback on any adverse effects on other > models would be good. > > Regards, > > Vivian Do we have the same project, on JSBSim ? What must be done for it ? -- Gerard ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] Re: New turbo/supercharger code
> -Original Message-
> From: [EMAIL PROTECTED] [mailto:flightgear-devel-
> [EMAIL PROTECTED] On Behalf Of Vivian Meazza
> Sent: 20 June 2005 13:13
> To: 'FlightGear developers discussions'
> Subject: RE: [Flightgear-devel] Re: New turbo/supercharger code
>
> Melchior FRANZ
>
> >
> > * Vivian Meazza -- Saturday 18 June 2005 12:22:
> > > void Thruster::setThrottle(float throttle)
> > > {
> > > _throttle = Math::clamp(throttle, 0, 1);
> > > }
> > >
> > > Will this prevent a negative value for:
> > >
> > > > > control="THROTTLE"/>
> >
> > No, but this will:
> >
> > ControlMap.cpp:83:
> >
> > map->src0 = map->dst0 = rangeMin(type);
> >
> >
> > ControlMap.cpp:222:---
> >
> > float ControlMap::rangeMin(int type)
> > {
> > // The minimum of the range for each type of control
> > switch(type) {
> > case FLAP0:return -1; // [-1:1]
> > case FLAP1:return -1;
> > case STEER:return -1;
> > case CYCLICELE: return -1;
> > case CYCLICAIL: return -1;
> > case COLLECTIVE: return -1;
> > case MAGNETOS: return 0; // [0:3]
> > default: return 0; // [0:1]
> > }
> > }
> >
> >
> > There's no THROTTLE, so we get the default 0 set for map->{src,dst}0.
> > You can avoid that by setting {src,dst}{0,1} explicitly, for example:
> >
> > > src0="-1" src1="1" dst0="-1" dst1="1"
> > control="THROTTLE"/>
> >
>
> Right - that fixes the problem.
With Melchior's valuable help I have developed a nasal simulation of the
Boost Control and Boost Control Cutout for the Hurricane. This should be
committed to cvs shortly. When a preset boost value is exceeded, the Boost
Control acts to reduce throttle opening. This action can be overridden by
the Boost Control Cutout which allows maximum boost. The output of the Boost
Control is smoothed by a low-pass filter selected by Melchior. You will
notice an overshoot and some lag if the throttle is opened quickly.
To make it work a patch (for cvs/head) is required to YASim - attached. A
new attribute 'supercharger' has been added to the aircraft config file.
When this is true, the attribute 'wastegate' no longer controls the
supercharger output. If you want to try the update to the Hurricane, you
will need to apply this patch. It will not adversely affect any other YASim
model, so far as I can tell.
Both the nasal and YASim patch are temporary; both will require reworking
when Andy comes up with his revision of YASim to include the new
supercharger code.
Any testing would be welcome, although Melchior is doing his best to break
it already! In particular any feedback on any adverse effects on other
models would be good.
Regards,
Vivian
yasim3.diff
Description: Binary data
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RE: [Flightgear-devel] Re: New turbo/supercharger code
Melchior FRANZ
>
> * Vivian Meazza -- Saturday 18 June 2005 12:22:
> > void Thruster::setThrottle(float throttle)
> > {
> > _throttle = Math::clamp(throttle, 0, 1);
> > }
> >
> > Will this prevent a negative value for:
> >
> > > control="THROTTLE"/>
>
> No, but this will:
>
> ControlMap.cpp:83:
>
> map->src0 = map->dst0 = rangeMin(type);
>
>
> ControlMap.cpp:222:---
>
> float ControlMap::rangeMin(int type)
> {
> // The minimum of the range for each type of control
> switch(type) {
> case FLAP0:return -1; // [-1:1]
> case FLAP1:return -1;
> case STEER:return -1;
> case CYCLICELE: return -1;
> case CYCLICAIL: return -1;
> case COLLECTIVE: return -1;
> case MAGNETOS: return 0; // [0:3]
> default: return 0; // [0:1]
> }
> }
>
>
> There's no THROTTLE, so we get the default 0 set for map->{src,dst}0.
> You can avoid that by setting {src,dst}{0,1} explicitly, for example:
>
> src0="-1" src1="1" dst0="-1" dst1="1"
> control="THROTTLE"/>
>
Right - that fixes the problem.
Before:
In the config file:
Outcome:
boost: 0
type: hurricaneIIb
YASim solution results:
Iterations: 1
Drag Coefficient: 1000
Lift Ratio: 1
Cruise AoA: 0
Tail Incidence: -0
Approach Elevator: 0
CG: -3.412, 0.000, -0.201
After:
In the config file:
Outcome:
boost: 0
type: hurricaneIIb
YASim solution results:
Iterations: 2202
Drag Coefficient: 6.39448
Lift Ratio: 886.777
Cruise AoA: 2.52573
Tail Incidence: -2.34135
Approach Elevator: -0.270048
CG: -3.420, 0.000, -0.200
The 2 throttle axes are additive now. All seems to be OK to move onto the
next phase: put something meaningful in
="/controls/engines/engine[0]/boost-control".
My WAG is that the problem is that
="/controls/engines/engine[0]/boost-control" is being initiated with
something that YASim doesn't like, Melchior's addition sorts that out.
Thanks Melchior - good spot.
Regards,
Vivian
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[Flightgear-devel] Re: New turbo/supercharger code
* Vivian Meazza -- Saturday 18 June 2005 12:22:
> void Thruster::setThrottle(float throttle)
> {
> _throttle = Math::clamp(throttle, 0, 1);
> }
>
> Will this prevent a negative value for:
>
> control="THROTTLE"/>
No, but this will:
ControlMap.cpp:83:
map->src0 = map->dst0 = rangeMin(type);
ControlMap.cpp:222:---
float ControlMap::rangeMin(int type)
{
// The minimum of the range for each type of control
switch(type) {
case FLAP0:return -1; // [-1:1]
case FLAP1:return -1;
case STEER:return -1;
case CYCLICELE: return -1;
case CYCLICAIL: return -1;
case COLLECTIVE: return -1;
case MAGNETOS: return 0; // [0:3]
default: return 0; // [0:1]
}
}
There's no THROTTLE, so we get the default 0 set for map->{src,dst}0.
You can avoid that by setting {src,dst}{0,1} explicitly, for example:
m.
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[Flightgear-devel] Re: New turbo/supercharger code
* Vivian Meazza -- Tuesday 14 June 2005 23:36: > Andy Ross wrote > > + Convince other folks to try the changes and report success. > > That would be nice - the silence is deafening so far :-(. Anyone like to > try Not being a pilot or engineer I can't say much. But the patch applied cleanly (apart from the MSDOS endings), compiled, and all aircraft that I tried seemed to (still) work well. Haven't compared any performance numbers, though. m. ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
