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Network of Friends => Tornado => Topic started by: Tom N on February 04, 2019, 09:29:07 PM

Title: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 04, 2019, 09:29:07 PM
So let's (re-)search   ;D
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 04, 2019, 10:22:48 PM
from Tornado / Re: About Tornado : Discussion
May 21, 2016
some heights:
Power Lines at about 155 ft
trees ~ 50 ft
SAM top range upwards 16 500 ft
AAA top range upwards 10 000 ft (or just little bit less)
missiles already shot when having been below 16 500 ft will follow higher beyond 16 500 ft
---------------------------

addition just now:
staying above 30 000 ft grants extra bonus-accuracy against enemy CAP
getting close to 50 000 ft and around  you'll make your enemy companion go haywire (loss of lock again and again, missiles fired will miss by 50:50 even not dropping chaffs or flares)
--------------------------------------------------------------------------------------

from Tornado / Re: About Tornado : Discussion
May 24, 2016
bridges and power Lines (and aircraft shelters) are fully solid
engine - fuel - cosumption
(a) 100 % +afterburner usage, 10720 lbs = 5 min 25 sec .23 (325 seconds)
      --> 33 Lbs per second or 1000 Lbs used up within 30.2 seconds

(b) only 100 % engine without afterburners,  10720 Lbs = 48 min  51 secs . 35 (2931.3 seconds)
       --> 3.657 Lbs per second or 1,000 lbs used up within 273.44 seconds

(c) using 63 % idle engines (but there only for using up 20 Units of fuel) 20 Lbs = 1 min 26 sec .99
      --> approximately 1000 Lbs used up within 4350 seconds (72 min and 30 seconds)

from May 25, 2017 - Tornado / Re: How realistic is Tornado's aerodynamics? Very.
This time prolongs in 35 000 feet to about 157 minutes if you would have started there with those 10720 LBs of full fuel, so the gain would be somewhere near of 2 hours still, I guess.
--------------------------------------------------------------------------------------

from today (youtube, February 4, 2019) as a comment to Frankie's uploaded video "Toying with SAM"
3:23 - 4:55 7 missiles launched by SAM while ECM is active (Ratio: 4.565 Msl/min)
5:01 ECM deactivated
5:09 - 8:07 19 missiles launched, ECM off (Ratio: 6.405 Msl/min)
--------------------------------------------------------------------------------------
from speedwagon and me since yesterday (February 3, 2019)

"me": In a video flying a 12minute  simulated campaign (DI's Tornado - Op: Desert Storm) struggling with 3 enemy CAP interceptors, there is this situation at 6:08 --> an enemy fighter accelerates from 510 kts (that's already mach 1.0 !!! ) to 650 kts at an average height of 15000ft in just 10 seconds

(615kts is the brim for reaching 1.3 mach; 675kts is the threshold to 1.4 mach in that height, roundabout --  that aforementioned leaping from a cozy speed of 500 kts to over 800 kts might be displayed in lower heights for IAS "behavior" is that way, higher numbers (just IAS, not mach or true airspeed) to reach nearer to the ground)

The Tornado ADV (10 missiles, 11000 lbs of fuel) under same circumstances starting with mach 1.0 / 510 kts at 15000ft speeding up for 10 seconds ends at barely 560 kts.

Same condition (510 kts, 15000ft height, 10 seconds aceleration) but jettisoned everything except 1000 lbs of fuel gets the Tornado to a speed of 570 kts with roughly 250 lbs fuel left ;-) .

Are the engines of the Tornado really that weak compared to MiG-31s, Su-27s?

Data:
Su-27 thrust power 2x 122.5 kN, at average weight of ca. 25000 kg
MiG-31 thrust power 2x 152 kN at average weight of maybe 30000kg

-- Tornado ADV thrust power 2x 73kN at an average weight of maybe 20000kg --
--------------------------------------------------------------------------------------
Hi Tom,

I watched your video and see what you mean about the acceleration rates shown by the RASH readouts on the HUD. You're asking some very interesting performance questions. Since DI has always done a sterling job with flight modelling I'm really curious about the accuracy of those used for enemy aircraft in Tornado.

Obviously many factors influence acceleration rates but a good place to start is a comparison of thrust-to-weight ratios (that is, engine thrust / aircraft weight). Here are some references I've been exploring:

Short primer from NASA: https://www.grc.nasa.gov/www/k-12/airplane/fwrat.html

List of thrust-to-weight ratios: https://world-defense.com/threads/thrust-to-weight-ratios-of-all-fighter-planes.1316/

Higher thrust-to-weight ratios equal higher acceleration and climb rates. Ratios greater than 1.0 allow vertical climbs. Here is a comparison of fighter/interceptors modeled in the game (number in parentheses is percentage above F3 ADV value):

Mig-31M    1.30    (+56%)
Su-27S      1.26    (+52%)
Mig-29M    1.19    (+43%)
F3 ADV      0.83

Clearly the F3 is at a serious disadvantage right out of the gate. This has always been acknowledged by the designers and overcome by aircrews using good tactics with multiple aircraft. Unfortunately in the game we are always fighting solo in the ADV so our tactics are somewhat limited.

In addition to this ratio the aerodynamic design of each aircraft is a major factor as to how quickly it can be maneuvered to an advantage. Maximum speeds, G-loads, rate-of-climb, turn rates, and service ceiling are just some of the items to consider. Some good info here (use Search button for aircraft thumbnails):

Aircraft info: https://www.fighter-planes.com/

I realize this doesn't directly answer your questions, such as "can any of these aircraft accelerate in straight-and-level flight from 510 KIAS to 650 KIAS in 10 seconds at 15,000 feet"? We'll most likely need some math for that. I'm going to see what I can find along those lines next.

Cheers,
SW

--------------------------------------------------------------------------------------

Hi Tom,

OK, here's my attempt at a rudimentary start with help from Sir Newton:
https://www.wikihow.com/Calculate-Acceleration

1. First we'll calculate average acceleration of the aircraft you had locked up on the radar:

∆v / ∆t = a


2. Next we'll calculate the acceleration capability of each aircraft using the data you provided in your post:

F / m = a

             Thrust       Weight
Su-27    245 kN  /  25000 kg =   9.8 m/s/s

Mig-31   304 kN  /  30000 kg = 10.1 m/s/s

F3 ADV  146 kN  /  20000 kg =   7.3 m/s/s

3.  ∆v / ∆t = a
--------------------------------------------------------------------------------------
Thank you very much, Speedwagon!
You provided the basic formulas, very well, very good!

But for v/t we need SI-units
https://en.wikipedia.org/wiki/International_System_of_Units
--> sorry, I realized too late, that you already did the right thing about using m/s values, just used IAS instead of TAS.

factor for mach 1 = 1235km/h = 343m/s (I used the google search line for those calculations)
and i used (just now EDIT 3rd and last ^^) a true airspeed calculator
( http://www.csgnetwork.com/tasinfocalc.html )
to calculate 650 kts IAS into 845 kts TAS and 510 kts IAS into 663 kts TAS
so it is not 650 knots - 510 knots, rather (1565km/h[435m/s] - 1228km/h[341m/s])  / 10s
= 94/10 (m/(s*s)) = ~ 9,4 m/(s^2) [2nd EDIT: that's nearly the value of earth's gravitational acceleration, holy s#&§ !]

and 304'000N for the Mig-31 with 30000kg ==> 304000 kg*m(/s^2) / 30000kg (result is correct)
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 05, 2019, 05:39:53 PM
I made a little mistake, twice:
the full cycle for launchng and reloading counts only for 6 missiles having ECM on and only for 18 missiles for ECM off,
so ratios now are 4.4Msl/min (ECM on) and 6.1Msl/min (for ECM off).

discrepancy error analysis regarding those acceleration values :
While counting these 10 seconds you can easily miss the start value by half a second and the other half second at the stop point having a whole second either too much or less than desired.

Other very rough estimations have been made about weight (some tons more or less are possible)
and height
(since only the number 15 is given for 15 000 ft, the range for that value might include all the way from 14 501 ft to 15 499 ft)
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Speedwagon on February 06, 2019, 02:59:28 AM
Hi Tom,

New thread was a good idea. Let's get to it!

I agree...should have used KTAS instead of KIAS in my calculations. However the conversions of "650 kts IAS into 845 kts TAS and 510 kts IAS into 663 kts TAS" at 15000 feet look a bit high. As noted at http://www.csgnetwork.com/tasinfocalc.html that calculator uses the rule-of-thumb "increase your indicated airspeed (IAS) by 2% per thousand feet of altitude to obtain the true airspeed (TAS)". Works OK for low speeds, not so good at high speeds.

If we use http://www.hochwarth.com/misc/AviationCalculator.html to include compressibility corrections the conversions are now 650 kts IAS into 769 kts TAS and 510 kts IAS into 615 kts TAS. (I crosschecked these numbers using a great E6B app for iPad https://www.gyronimo.com/e6b-pro in case you're interested.)

As for IS-units...I actually did use them in my original calculations using KIAS but somehow those lines didn't make the cut-and-paste to this new thread. I've copied them here and put new calculations using KTAS under each line for comparison:
________________________________________

∆v / ∆t = a

1. First we'll calculate average acceleration of the aircraft you had locked up on the radar:

KIAS  (650 kts - 510 kts) / 10 sec = (334 m/s - 262 m/s) / 10 sec = (72 m/s) / 10 sec = 7.2 m/s/s
KTAS (769 kts - 615 kts) / 10 sec = (396 m/s - 316 m/s) / 10 sec = (80 m/s) / 10 sec = 8.0 m/s/s

3. By these figures it appears that even the F3 can pull off that kind of acceleration. However, that's not what you saw in the game:

KIAS  (560 kts - 510 kts) / 10 sec = (288 m/s - 262 m/s) / 10 sec = (26 m/s) / 10 sec = 2.6 m/s/s
KTAS (670 kts - 615 kts) / 10 sec = (345 m/s - 316 m/s) / 10 sec = (29 m/s) / 10 sec = 2.9 m/s/s

_________________________________________

So using TAS rather than IAS results in ~11% higher acceleration rates. Good catch! Let me know if you see any other errors in my math.

Yes, our analysis definitely has its limitations when it comes to measuring time / range and estimating aircraft weight. But we have to begin somewhere.

Regards,
SW

Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 06, 2019, 05:08:41 PM
Hi Speedwagon,

my bad about expecting the SI calculating error,
but all this hassle about ktas (Knots True Air Speed) and kias (Knots Indicated Air Speed),
"we" (Please, Frankie?) could avoid by modding the mach number behind the speed indicating gauge on the left side of the front MFD or in the upper left corner in HUD (by pressing "alt" + "H") to show more decimal places (so mach 1.xxx), because the mach numbers in Tornado seem to be in TAS.

It would still be great to find all the formulas in the code, to "see and understand the matrix".

EDIT: And thank you very much for all those app recommendations.

Kind regards,
Tom
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Speedwagon on February 06, 2019, 05:45:06 PM
Hi Tom, no worries and you are most welcome. Please let me know if there are apps you recommend as well.

>> ...the mach numbers in Tornado seem to be in TAS <<
That's an interesting statement. I'll have to experiment with that a bit.

>> It would still be great to find all the formulas in the code, to "see and understand the matrix". <<
An excellent idea. Frankie, do you know if those reside in FLIGHT.EXE or some other location? What would be our best method of looking at them?

To continue our performance research, here are several links we can explore:

1. Forum discussion Proof: F-35 can out-accelerate Su-27/35 in subsonic region --
http://www.f-16.net/forum/viewtopic.php?f=55&t=52510&sid=cb74d3f973ae3be39186852f2e97cc85

Some interesting statements here:

"We have read from a TsAGI report that a Su-27 could accelerate from 600km/h to 1100km/h in 15 seconds, on 1000m, with 18920kg flying weight. The average acceleration is 9.25m/s2 from 600-1100km/h at 1000m."

"We have also read from F-35 240-4.2 configuration report that F-35 could accelerate from 0.6-0.95 mach (696km/h-1102km/h) in 17.9 seconds, under Maneuver Weight at 15000 ft (4527 m)."


The post includes performance graphs of acceleration for several aircraft as well as formulas for calculating time required to accelerate. Lots to explore here.

2. Excerpt from 1990 AW&ST article Aviation Week Pilot Report on the Su-27 --
http://aviationweek.com/site-files/aviationweek.com/files/uploads/2015/01/1990-%20Su-27%20Pilot%20Report%20%282%20of%202%29.pdf

Another interesting statement:

"Although we did not perform any acceleration checks in the Su-27, Pougachev [the Soviet test pilot] estimated that the time to accelerate from 330 kt. to 540 kt. in maximum afterburner would be less than 10 sec."

3. Website with three Panavia Tornado manuals --
http://www.avialogs.com/index.php/aircraft/europe-and-consortiums/panavia/tornado.html

Select the one titled "Performance Data" and go to page 238. This is "Part 5 - Acceleration". Lots of performance graphs for low and high altitude acceleration.

Cheers,
SW

One addition: I found the same post in #1 above in another forum so the discussion is different:
https://forum.keypublishing.com/forum/modern-military-aviation/144262-proof-f-35a-can-out-accelerate-su-27-35-in-subsonic-region
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 06, 2019, 10:03:40 PM
http://www.thedrive.com/the-war-zone/16752/how-sly-raf-tornado-crews-repeatedly-killed-u-s-navy-f-14s-and-f-a-18s-in-training

found this article while searching for the manuals
(attempts to download them resulted in invitations to register for 32 - 80 €)

It is about Phil Keeble (Tornado ADV F3 - pilot),
"he explains how the Royal Air Force used some very well tailored tactics to take on the very best fighters the U.S".

There is a link to an aircrew interview youtube channel as well:

https://www.youtube.com/watch?v=eM-1gBW4Ng0
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Speedwagon on February 07, 2019, 12:53:12 AM
Thanks for the links. Amazing that F3 crews could outfox pilots in F14s and F18s. Just received his new book today:
https://www.goodreads.com/book/show/34415978-patrolling-the-cold-war-skies

Tornado manuals used to be available here but are not listed anymore. However there are many others you may find of interest:
http://www.flight-manuals.com/index.html
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Speedwagon on February 07, 2019, 04:50:07 PM
Hi Tom,

>>...the mach numbers in Tornado seem to be in TAS<<

Here is some game data recorded at 10000 feet. For example, with the HUD displaying MACH (Alt+H), the value is 1.0 when IAS is between 580 - 547 kts. Fly one knot faster or slower and MACH value in the HUD will change to 1.1 or 0.9 respectively. The KTAS and MACH values were calculated using the E6B app. [Edit: assuming ISA pressure and temperature at that altitude]

           |--------Ranges--------|
HUD     KIAS     KTAS     MACH
             580       653       1.02
1.0        547       618       0.97
              33         35       0.05

             546       617       0.97
0.9        479       544       0.85
              67         73       0.12

             478       543       0.85
0.8        411       469       0.74
              67         74       0.11

             410       468       0.73
0.7        376       431       0.67
              34         37       0.06

             375       429       0.67
0.6        308       354       0.56
              67         75       0.11

             307       353       0.55
0.5        274       316       0.49
              33         37       0.06

The range of KIAS and KTAS values for each HUD reading is large, in some cases twice as much (~35 kts -vs- ~75 kts). This highlights the limitations of using HUD readouts of MACH as precision data. The MACH ranges are somewhat "centered" around the HUD MACH values.

>>...modding the mach number behind the speed indicating gauge on the left side of the front MFD or in the upper left corner in HUD (by pressing "alt" + "H") to show more decimal places (so mach 1.xxx)<<

I'm not sure if it's possible to modify the HUD display. Frankie will have to advise us on that one. If not, perhaps a more accurate MACH readout could be added to the status bar.

I also evaluated time-to-go data on the TAB Flight Plan display while tracking to a waypoint. As expected, it appears to be using KTAS.

Hope this helps!

SW
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Frankie on February 07, 2019, 06:14:52 PM
The answers (i.e., formulae and stuff) you are looking for is most probably inside the AVIONICS.ASM source file.
Correction. The HUD.ASM file seems to contain the most lines to do with Mach values.
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 07, 2019, 09:39:41 PM
Thank you Speedwagon for your time spent in the speed listing effort, good stuff!

Thanks, Frankie

I think i met your modified "ride table" in there, from 35 ft to 1000 ft in the avionics.asm

The avionics.asm seems to contain all orders for calling (getting information), moving (enabling a system), jumping (overriding to something) regarding autopiloting mainly, but also SAM flight physics and HUD "RASH" display order. So avioncs.asm handles the total behavior of the autopilot (from enabling and rules for activity to rules of disengagement due to canceling by either pilot or "B" risk warning lamp below the e-scope, or due to complete system destruction.
Moreso it defines the thrust of the Tornado and the power levels of the engines (dry and full throttle values)

There are some interesting sidewinder (32,767ft) and skyflash (131,071ft) ranges in the HUD.asm file.

No true flight physics formulas found in both files. Only pixel to ft calculations there for ranges in the radars and for bomb drop lines. And some other stuff that needed defining (roll and pitch within 359 numbers and so on)

I think, we are digging deeper into the matter now  ;)  (I'll edit my messages here over and over, it's so important and encouraging to press "modify"!  8) )
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 09, 2019, 11:02:33 AM
The mach number display in the HUD.asm file is assigned to get toggled as follows:

;* check for mach num option toggle
;----------------------------------

      KTEST   KF_HUDOption
      jz   @F

      xor   MachOption,1   ;toggle mach num option

      jmp   InitCont


there is a command line constantly repeating throughout the HUD.asm
but this might highly probably refr to some external source: "call UpdateAirSpeed"
OR at the beginning in the file: "EXTRN   DispMachNum:WORD"

so the values get grabbed from somewhere else.
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Frankie on February 09, 2019, 12:33:01 PM
Hi Tom N

The salient code portion to calculate the Mach Number is found inside MODEL.ASM file:

(http://www.moodurian.com/tornado/images/di_tor_speed_mach_01.png)
When you need to search for a string inside an entire folder, you need a tool like Agent Ransack to retrieve every file
that contains the search value, and shows you where in which lines the search value is found.
[/size]

(http://www.moodurian.com/tornado/images/di_tor_speed_mach_02.png)
Variables declarations.

(http://www.moodurian.com/tornado/images/di_tor_speed_mach_03.png)
Calculation of true air speed (Vtas variable)

(http://www.moodurian.com/tornado/images/di_tor_speed_mach_04.png)
Calculation of Mach speed (Mach1 variable)

(http://www.moodurian.com/tornado/images/di_tor_speed_mach_05.png)
How DispMachNum is derived. Converts MachNum[*16] to *10 scaled (MachNum * 5 / 8)


I've attached the MODEL.ASM file in this post.

Hope this helps,
Frankie Kam
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Speedwagon on February 09, 2019, 03:32:02 PM
Thank you, Frankie. It looks like the flight physics formulas reside in MODEL.ASM as well.

Tom, there is aircraft performance data for drones in AIRCRAFT.ASM, including acceleration (search for COM_ACCEL).
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 09, 2019, 09:33:09 PM
I'm confused about the whereabouts of those asm files.
Aren't they supposed to be in the game folders/subfolders?
(i searched, i miss them on my PC)

EDIT: You might have mentioned maybe much earlier, Frankie, that this is source code content only.
(or it's just now my guess)
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Frankie on February 10, 2019, 08:25:33 AM
Hi Tom

https://github.com/tornadorebooted/tornado-dos-flightsim
You can download the source code by clicking on the "Clone of download" button.

Regards
Frankie Kam

P.S., In case you are interested, the attached work-in-progress FLIGHT.EXE uses the bottom status bar to show the airspeed in both Knots and Mach.

(http://www.moodurian.com/tornado/images/machknots.png)

Hit the '4' key or Alt+H to change from one unit of measurement to the other.

The Mach/Knots value in the simulation is also shown on the HUD when you hit Alt+h.

(http://www.moodurian.com/tornado/images/machknots2.png)

Hope this helps.
Frankie Kam
Title: Re: Technical Data and Numbers (some formulas'n'numbers found by "playing")
Post by: Tom N on February 11, 2019, 04:56:52 PM
source code - loaded down,
another flight sim video about being chased inefficiently - loaded up

displaying the mach number in external view is a good idea, but the mach number needs to be elongated
(2 more decimal places, just 2 more)

here, there is some problem for ai airplanes, when you beg them to fly higher than 50 000 ft:
https://www.youtube.com/watch?v=oDMuR1M6c3Q