Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Kweassa on May 16, 2005, 04:52:24 AM
-
*Deck speed test alt: 100ft (+/-10ft)
*Fuel: 100%fuel, no fuel burn
*All ordnance loadout tested with cfg1(configuration1)
-Fw190A-5-
cfg1(MG151/20 x2, MG-FF x2): 339mph
cfg1 @ 21,000ft: 406mph
cfg2(MG151/20 x2): 339mph
w/bombrack(bomb intact(500kg)): 322mph (-17mph)
w/bombrack(bomb dropped): 330mph (-9mph)
w/WGr21(rockets intact): 319mph (-20mph)
w/WGr21(rockets fired): 323mph (-16mph)
-Fw190A-8-
cfg1(MG151/20 x4): 351mph
cfg1 @ 19,000ft: 405mph
cfg2(MG151/20 x2): 351mph
cfg3(MG151/20 x2, MK108x2): 350mph
w/bombrack(bomb intact(500kg)): 334mph (-17mph)
w/bombrack(bomb dropped): 345mph (-6mph)
w/WGr21(rockets intact): 330mph (-21mph)
w/WGr21(rockets fired): 334mph (-17mph)
-Fw190F-8-
cfg1(MG151/20 x2): 351mph
cfg1 @ 19,000ft: 403mph
w/bombrack(bomb intact(500kg)): 335mph (-16mph)
w/bombrack(bomb dropped): 347mph (-4mph)
w/rail(bombs intact(50kgx4)): 331mph (-20mph)
w/rail(bombs dropped)): 349mph (-2mph)
w/PB1(rockets intact): 336mph (-15mph)
w/PB1(rockets fired): 349mph (-2mph)
-Fw190D-9-
cfg1(MG151/20 x2): 375mph
cfg1 @ 21,000ft: 427mph
w/bombrack(bomb intact(500kg)): 355mph (-20mph)
w/bombrack(bomb dropped): 367mph (-8mph)
Interesting observations:
* The added drag of external equipments is the least with the F-8. Only -4 mph with empty bomb rack, and -2 mph with empty rocket rails...!
* No difference in speed between 2x 20mm load outs and 4x 20mm loadouts for the A-5 and A-8. Maybe HTC forgot to add in(or remove) weights for those two guns, or maybe the weight of the guns and ammo for 2x 20mms isn't as much as we would expect.
* Only about 1mph speed difference for the A-8 when equipped with MK108. I guess the MK108 isn't really much heavy.
* The weight/drag of the 500kg bombs, seem to effect speed by 8~12mph.
* The weight/drag of 2x WGr21 rockets, seem to effect speed by 4mph. Thus, roguhly each rocket would be equivalent -2mph from the top speed when inside the pod tube.
* The weight/drag of 12x PB1 rockets, seem to effect speed by 13mph. Thus, roughly each rocket is equivalent to -1mph from top speed.
-
I dont think adding weight without adding drag (i.e. internal guns) shouldn't effect top speed, only acceleration, unless the weight move the CG enough to change Ao'A
-
More weight = more lift needed = more AoA = more drag = less speed.
-
190 negative Ao'A at high speed = no factor.
-
Negative AoA would produce negative lift = crash. Learn a little about aerodynamics.
-
... and why do you have a link to this forum in your sig?
-
Negative AoA does not necessaryly produce negative lift. Some profiles give still some lift at -2 degrees AoA.
Increasing wight a bit does not matter much for the top speed.
-
Pretty silly that D9 loses the most speed from its DT rancj considering it's the most aerodynaic DT rck of all FW190 by far.
-
No it does not matter much, but you can't add weight and not have it affect performance. If that was true it wouldn't matter how much weight you add.
-
Look for curve 4 (B4 + MW 50 + 2 MG 151 + 2 MG131 + ETC 504) (http://www.terra.es/personal2/matias.s/d9speed2chart.jpg)
605 kmh / 376 mph at sea level.
-
thats interesting... i just did an offline test for the P51b and i was suprised to discover that the DT rack of the pony doesnt hurt its speed at all.
-
Pony will be gelded after it gets redone - only 190's for now.....
-
Originally posted by GScholz
Negative AoA would produce negative lift = crash. Learn a little about aerodynamics.
wrong.
GS, some minimal aoa's that are negative still produce minimal lift... ie enough to maintain straight and level flight.
-
I support the opinion of the author on this site. :mad:
http://jagdhund.homestead.com/files/DoraData/horizontalgeschwindigkeiten.htm
Dora of AH is "4 - Sonder - Notleistung (B4) mit Laderdruckerhoehung mit MW50 u. 1.8ata. ".
For speeds without the ETC 501 ordanace rack add 8 km/h (5 mph) below and 12 km/h (7.5 mph) above critical engine (6.5km). Since the ETC 504 had a slightly better drag coefficient I would estimate speed penalty of about 6km/h (3.7mph)to 10km/h(6.2mph).
-
That site ALSO indicates 377 mph at sea level WITH (mit) ETC 504, 383 mph WITHOUT ETC 504.
-
FW-190A8 should be hitting between 565kph and 595kph depending on what varient they model.
I think Pyro is redoing the FM soon. Last word I got was no real changes to the FM until all the artwork is completed.
All the best,
Crumpp
-
Crumpp, 351mph translate into ~564 km/h, so the speed of the current A8 pretty exactly matches that of an A8 with BMW801D and 1,65/1,58 ata boost.
I don't think HTC will model an A-Series FW190 with a BMW801F and boost pressure of around 1.85 ata (not sure how much, but you are the expert here).
Atleast for the D9 i can assure anybody that the AH Dora's speeds represents a good performing plane using MW50 injection.
Only bug/mistake i see so far are the E6B powersettings.
For a D9 with MW50 it should be this:
Special EP (10 Min Limit -> translates into AH WEP speed)
2100PS@3250rpm@1.8ata
Take-off/Emergency (substainable 30 mins, as profen by TAM reports from September 44 and JUMO213A Handbook -> translates into AHs max speed without WEP)
1750PS@3250rpm@ 1.5ata
Climb&Combat (not limited)
1620PS@3000rpm@1,4ata
P.S.: And if anybody comes up again with 620km/h and/or 640km/h on the deck for a Dora or says that ~375mph should be with ETC rack, those points have been discussed to death. Those threads can be found here and in the Luftwaffen Experten Message Boards. I will not discuss that again.
-
Can you point out where in the LEMB has been "discussed to death" the deck speed of B4 + MW50 D9 with or without ETC?
The only links I remember are the following:
http://p069.ezboard.com/fluftwaffeexperten71774frm9.showMessage?topicID=357.topic
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=146949 (http://www.hitechcreations.com/forums/showthread.php?s=&threadid=146949)
Just to point out some comments:
"It doesn't matter that the power settings did exist (in case for curve 1, 3 & 5) or where a proposal or may have existed.
I draw a very straight line between documented facts and "wishful thinking".
"
But now we are talking only about curve 4.
As far as I remember, here the only comment related to curve 4 was that it was calculated (as most of the performance curves you will find for any aircraft, quite more representative than any individual test with a particular plane, with a particular engine, with a particular pilot and with a particular wheather contitions, as long as the calculation formulaes and parameters are right).
-
Originally posted by Bodhi
wrong.
GS, some minimal aoa's that are negative still produce minimal lift... ie enough to maintain straight and level flight.
They would have to be pretty darn "minimal".
-
Mando this link should help you http://p069.ezboard.com/fluftwaffeexperten71774frm9.showMessage?topicID=372.topic
This is basicly the current endpoint of the long lasting D9 performance discussions. I will not do the work for you and search all post from the past years and link them here.
-
Originally posted by GScholz
They would have to be pretty darn "minimal".
-4 degrees for zero lift Ao'A on an airfoil is the lowest number I've seen. In general, as camber increases, the zero lift angle of attack goes down. I have a textbook, Aerodynamics for Naval Aviators that explains it in depth.
-
Originally posted by GScholz
No it does not matter much, but you can't add weight and not have it affect performance. If that was true it wouldn't matter how much weight you add.
I know that seems logical; but I know also that gliders often carry (dumpable) water ballast which improves performance in some regimes.
I don't pretend to know enough about aerodynamics to explain it.
-
Originally posted by Naudet
Mando this link should help you http://p069.ezboard.com/fluftwaffeexperten71774frm9.showMessage?topicID=372.topic
This is basicly the current endpoint of the long lasting D9 performance discussions. I will not do the work for you and search all post from the past years and link them here.
That link shows 3 real plane tests. As pointed by Hohun, none of them representative of any B4/MW50 D9:
002 test showed defective engine. 006 too draggy, without MW50 (115l tank used for fuel), with 4350 Kg, incorrect propellor and what is described as "untuned" (new) engine. 043 is described as even more conflictive (no time to dig into it).
Finally, Hohun tried to extrapolate speed curve for the 002 airframe with a working engine without information about 002 drag neither weather conditions of the 002 test.
Without considering these tests, Hohun reached the following coclussion:
"According to my calculations,
578 km/h @ 0 km with 1780 PS (shaft equivalent power ca. 2100 PS)
leads to
613 km/h @ 0 km with 2100 PS (shaft equivalent power ca. 2460 PS)
"
And extrapolating test 002, Hohun reached the following conclusion for 002 airframe and working engine:
"This gives the following performance compared to curve 4:
0.0 km 596 km/h 606 km/h
2.2 km 634 km/h 646 km/h
3.6 km 633 km/h 646 km/h
6.4 km 689 km/h 694 km/h
8.0 km 660 km/h 665 km/h
"
I'm still missing any determining prove against the FW chart curve 4.
Naudet, dont think I'm expecting any new comment/reply from you, but comments from Hohun would be welcome, as always
:)
-
Originally posted by Seeker
I know that seems logical; but I know also that gliders often carry (dumpable) water ballast which improves performance in some regimes.
I don't pretend to know enough about aerodynamics to explain it.
Denser objects have higher terminal velocity than less dense.
Maybe glider pilots take advatage of this?
-
Originally posted by Flyboy
thats interesting... i just did an offline test for the P51b and i was suprised to discover that the DT rack of the pony doesnt hurt its speed at all.
It shouldn't hurt speed as the pylons were installed as basic equipment. Take them off and you would see an increase in speed.
My regards,
Widewing
-
Originally posted by bunch
Denser objects have higher terminal velocity than less dense.
Maybe glider pilots take advatage of this?
I thought terminal velocity was a function air density and frontal area/drag? Object density should have no factor.
Kind of like a sky-diver. Body flat, arms out, falls slower. Arms flush with the body, legs together, head down, falls faster.
EDIT: Water ballast is probably used to control CG for various flight regimes.
-
double post -.-
-
Yeah, i wasnt very clear.
2 objects of the same shape & size, the denser has a higher teminal velocity.
leavine the medium out of the question, terminal velocity is a function of density & shape coeffiecient
-
Originally posted by bunch
Yeah, i wasnt very clear.
2 objects of the same shape & size, the denser has a higher teminal velocity.
leavine the medium out of the question, terminal velocity is a function of density & shape coeffiecient
I'd love to argue, but I did a little checking to see if I was right, and I wasn't wholely...
Anyways, density of the object does play into terminal velocity. BUT the density of the medium (IE Air) does also play into it. Lower altitude, denser air, lower terminal velocity. Higher altitude, less dense air, higher terminal velocity. Vacuum, no terminal velocity.
EDIT and here I am trying to argue through a typo...you meant 'leaving' instead of 'leave' in that post, didn't you?
-
According to this document all of HTC's LW modeling is spot-on.
http://www.onpoi.net/ah/pics/users/150_1116386659_lw_data_nasm.gif
-
Originally posted by Tails
I'd love to argue, but I did a little checking to see if I was right, and I wasn't wholely...
Anyways, density of the object does play into terminal velocity. BUT the density of the medium (IE Air) does also play into it. Lower altitude, denser air, lower terminal velocity. Higher altitude, less dense air, higher terminal velocity. Vacuum, no terminal velocity.
EDIT and here I am trying to argue through a typo...you meant 'leaving' instead of 'leave' in that post, didn't you?
"e" and "g" are not so different.
dont go around labeling everything, just be free, man....i was assuming same medium for the terminal velocity comarison "of course"...apparently i assume you can read minds over the internet also
-
Originally posted by Seeker
I know that seems logical; but I know also that gliders often carry (dumpable) water ballast which improves performance in some regimes.
I don't pretend to know enough about aerodynamics to explain it.
CG balancing. If the pilot is a flyweight or hefty it is better to add a bit of ballast than to fly with constant elevator trim. Some planes pump fuel between fore and aft tanks to achieve the same, but for small planes gliders are of course the ones most affected by the added drag of trim.
-
Originally posted by bunch
"e" and "g" are not so different.
dont go around labeling everything, just be free, man....i was assuming same medium for the terminal velocity comarison "of course"...apparently i assume you can read minds over the internet also
Nope, cant read minds. But sometimes I go and screw up thinking I can.
-
* No difference in speed between 2x 20mm load outs and 4x 20mm loadouts for the A-5 and A-8. Maybe HTC forgot to add in(or remove) weights for those two guns, or maybe the weight of the guns and ammo for 2x 20mms isn't as much as we would expect.
The contribution of the additional weight to incremental induced drag is generally negligible for max level speed situations. At max level speeds parasitic drag dominates overall drag while induced drag is a pretty minor factor. The incremental change in aoa for the additional weight is most likely pretty insignificant resulting in no noticeable contribution to increased drag given the high speeds associated.
Tango, XO
412th FS Braunco Mustangs
-
Mando, your are just to funny, actually HoHun and i proved that curve number 4 is correct, maybe a little bit optimistic but still correct and therefor that FW performance calculations are not way off as others might claim.
Henning doesn't point out that they are none representative for a D9 B4/MW50, cause he knows that there are no flight tests for MW50. Neither FW or the LW did them, because after the accidential crash of the first MW50 prototype the tests were only done on the ground. And so far noone could dig out any flight tests for D9s with MW50 from any archive.
I provided Henning with those tests, because we needed material from which we could get the drag data of a production series plane so that Henning could use that drag data and put it together with the JUMO213A power curve.
All those three plane are serial production planes, they are very representative for the D9, the discussion between Henning and me was about the exact and detailed condition of those planes not about them being unrepresentative.
006 too draggy, without MW50 (115l tank used for fuel), with 4350 Kg, incorrect propellor and what is described as "untuned" (new) engine.
You are mixing up to tests here, the one we used to verify and crosscheck the powercurces has the 006 in standard serial production condition for early 1945. The untuned engine and D12 prop were used in a different test for range measurements.
This gives the following performance compared to curve 4:
0.0 km 596 km/h 606 km/h
2.2 km 634 km/h 646 km/h
3.6 km 633 km/h 646 km/h
6.4 km 689 km/h 694 km/h
8.0 km 660 km/h 665 km/h
Funny, the data we got for 002 with ETC504 (002 had polished surfaces, this btw explains why 006 seems so much draggier, cause it had no polish) matches the AH speed curve for MW50 almost spot on.
It manages 370mph@SL which is just 2-3mph faster than AHs D9. 2-3 mphs are negligible, thats within productions variation. Even if some D9s managed 377mphs@SL with ETC504 the 10mphs speed difference to AHs D9 would be within production variation (10mphs are roughly a 3% difference). No need to change anything or complain about AHs D9 just doing 367mph with ETC504.
And that's why i am argueing against you. You always pinpoint out that single calculated chart in any thread and mention it as it would be the final truth. While i know through my researches and analysis - with the much appreciated help from Henning - that there is actually no final truth. The more sources i dig up, the more plane tests i get, the more questions and uncertainties arise.
Real planes have performance spans, and for the D9 i have a pretty clear picture of how wide this span is. And as long as AHs D9 is within those borders - and it is - there is no need to call for a change or complaining.
-
Note that the P38J does not loose any speed for taking off with droptanks and droping them.
Well, lets say it can not gain speed from not using droptanks, guess the pylons are mounted fixed and cant be removed.
Now here comes the question ... are the official numbers for P38 speed with droptank/bomb racks? would think they measured clean P38s.
-
Schutt, look at the how the droptanks/bombs are mounted on the P-38J. They are strapped onto a fixed hardpoint at the wingroots. It doesn't use a separate universal rack like the 190s.
-
Naudet, calculations are not always optimistic, but should be representative for most of the real planes (considering that these planes are within the deviation limits of the parameters used into the calculations). I would expect calculated speed +- 3% as a credible margin, not just calculated speed -3%.
BTW, you said you had the calculations used (in a page not posted, but from the same source as the chart). If these calculations shows formulae and parameters, drag used for the calculation should be present there, as well as total power curve and propeller parameters, and also the weigths.
AH wise, it represents -9 mph compared with curve 4 (or -18 mph if we add a +3% to curve 4 as most optimistic value). AH wise that speed is just what would put the D9 into Tempest/La7 leage at low alts.
Now it depends on everyone particular point of view to consider that ok or not.