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Guest Ron Freimuth

A:TURB ENG1 JET THRUST & augmentation

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have been building a panel for an aircraft, not of my making.have been thinking that the kick from augmentation was not what it should be. i made a test gauge to look at (A:TURB ENG1 JET THRUST, number) and was horrified to find that toggleing the after burners had no noticable effect. there should be a 20% or greater increase in thrust.i know that rpm is only indirectly related to post turbine augmentaion through the increased airflow, from speed. i am seeking confermation that turb eng1 jet thrust is the right tree to bark at, and seeking insight to what i might need to tweek in the airfile or aircraft cfg.i have looked at several airfiles to compare, but they ae all very different in structure...capt sims f104 leading the way in complexity.seems like there should be a referance to static or dry thrust and another for wet/augmeted thrust. believing that military types are the step children of flight sim is there really a dual treatment of max power vs full mil power. or is the whole augmentation thing dependent on programing trickery like more then 4 engines.

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In FS2004, the influence of "reheat" on airspeed is modelled by multiplying the normal thrust with a factor, dependant on the MACH speed.In the .air file, this parameter is called "Turbine Afterburner Thrust Factor vs. Mach#" (type TBLDB, number 1524).Does exactly what you want,Rob Barendregt

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hmmm, in the file i have;Record: 1524 Afterburner Thrust Scalars vs MachPoints: 100.000000 1.0000000.200000 1.0000000.400000 1.0000000.600000 1.0000000.800000 1.0000001.000000 1.0000001.200000 1.0000001.400000 1.0000001.600000 1.0000001.800000 1.000000the payware 1524 is not that different. it varys from 0.999900 to 1.000000 here's another with a greater then 1 parameter;0.000000 1.2800000.300000 1.2000000.900000 1.2000001.300000 1.2000001.700000 1.1000002.000000 1.050000perhaps im am at the wrong tree. the plane i'm useing runs all the way up to its max speed with no burner. no differance in acceleration is seen with or with out burner, and no brick wall at compression wave contact. (A:TURB ENG1 JET THRUST,ft lb per second) does not reflect burners. i fear that the airfile i have was tweeked to get the desired end speed without useing the correct parameters.i think i heard that flight sim does not model super sonic speeds and to get the desired end results you have to fudge things. if i kick up the power i beleive ill get to fast. perhaps limit upper throttle when burners are off?

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Well, in the first two examples "reheat" obviously isn't modelled at all..(in most jets I know of, especially the freeware ones, the designer just forgot to model reheat in the .air file, or is just unaware of the possibility).But in the last example (with values > 1) you WILL see a difference in accelleration, topspeed, thrust in A:TURB ENG1 JET THRUST, and fuel usage.It DOES work if modelled properly. >>i think i heard that flight sim does not model super sonic speeds ....See above. It's not an FS2004 restriction, but a "designer" restriction :-)Rob

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Hello,reheat is modelled, when enabled in the flight model will give you an increase in the SFC and thrust factor unless you only have ones in that table. Depending on the airflow you can get a 40% thrust increase.Ian

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thanks rob & ian,messed with the numbers and see the results,if i might impose; what method would you suggest for stopping this guy from supercruising through the transonic compression wave without burners?

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Hello Ridgell,add wave drag in the .air fileRecord 0430 is wave drag. zero ish up to Mach divergence, big jump up them tailing off depending on the level of technology used in the wing-body blended shape.Check other models to see ideas of how other people.Ian

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gracias amigo! the model is the viggen, much the same as a mig21 or mirage in shape. you have any recomendations as to a good wave drag file to look at. im finding out that alot of my payware airfiles are no better thought out then freeware created by a educated OCD.

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Hello Ridgell,here is some data for a T-38 Talondelta CD_m MN Cdo CD_m MSFS units0.1 156 0 00.2 156 0 00.3 154 -2 00.4 153 -3 -10.5 152 -4 -10.6 151 -5 -10.7 149 -7 -10.8 149 -7 -10.9 245 89 181 320 164 341.1 374 218 451.2 411 255 521.3 431 275 561.4 438 282 581.5 440 284 581.6 440 284 581.7 435 279 571.8 435 279 572 430 274 562.2 430 274 562.4 425 269 552.6 425 269 552.8 420 264 543 420 264 543.2 415 259 53Ian

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thx ian,that is record 0430 ?looks very different then Record: 0430 Zero Lift Drag vs. MachPoints: 17000006980655550105107115120120120120there ae no speed referances on this record like the other, makes manipulation seem arbitrary. yiks!

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Hello RidgelThey are both in steps of 0.1 MN see the AirEd.ini help from M0.0 to M3.2Sorry I meant Cdo_M is table 0430 not 0411Ian

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>Hello Ridgel>They are both in steps of 0.1 MN see the AirEd.ini help from>M0.0 to M3.2>>Sorry I meant Cdo_M is table 0430 not 0411>Ian Steps of 0.20 Mach! I simply count .2, .4, .6, .8, ... from the left. Aired assumed unsigned 16 bit integers, in fact, they are signed. '-1' = '65535', '-2' = "65534", etc. AAM showes the correct, floating point values. Ron

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aired,i used that a year or so ago and after useing it could not get airupdate to work. while aired seemed to be more advanced a solution i have not used it again after a windows and fs9 re-install for fear that it would preclude my use of airupdate...since you mention it, is there actually something to my inability to use airupdate after aired, or perhaps something was amiss with my system.

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>aired,>>i used that a year or so ago and after useing it could not get>airupdate to work. while aired seemed to be more advanced a>solution i have not used it again after a windows and fs9>re-install for fear that it would preclude my use of>airupdate...since you mention it, is there actually something>to my inability to use airupdate after aired, or perhaps>something was amiss with my system. Lots of people use both aired and airupdate. However, one can mess up AIR files with either. Ron

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