Throwing some light on rates of turn

[MiG-3U]

Originally Posted by Crumpp

It took a few seconds to say, "Yes you can use EAS to convert the performance to any altitude" with any airplane.

And did the correct mathmatical mechanics to show the process to change altitudes given a speed and angle of bank.

The problem is that power varies with altitude and hence the speed and angle of bank for the best turn varies as well. You assume given speed and angle of bank which is not correct for this case.

Anyhow, incompressible flow theory may have been used by RAE or whoever - what is important for our game is what is the most close to reality.

[Holtzauge]

Crumpp: Posting the NAVWEPS chart and showing the relationship between 21 s, 68 deg bank angle and the 115.6KEAS*1.37 shows you have no idea about what you are doing: That chart just shows the relationship between these variables in a stationary turn.

You use the unsupported preconception that the Spitfire can hold a sustained turn bank angle of 68 deg at 20,000 ft and this is where you go wrong. The RAE report R&M 2349 by Morgan & Morris actually states the bank angle for the Spitfire at 20,000 ft which is 51 degress, not the 68 degrees you pulled out of a hat. Now instead enter the RAE turn speed of 141 mph TAS and bank angle of 51 deg in that same chart. This gives us 11.4 deg/s. This is equivalent to a turn time of 31.5, not 21 s. You see now?

In addition, I really like the circular argument you use to MIG-3U's question about the impact of power: First you assert that the Spitfire will have a turn time of 21 s at 20,000 ft without any power analysis whatsoever, period. Now you suddenly claim it's dependant on which Merlin version was used, compressibility corrections etc. Are you perhaps beginning to feel the heat and want back away from the 21 s claim?

Which brings us to the question of proof: I don't think you understand how this works: You have made a claim that the Spitfire turn time at 20,000 ft is 21 s. If you want to convince us then YOU need to provide proof of this either through references or calculations showing where the RAE who claim 31.5 s got this wrong. I wish you good luck with that.

Personally, I'm comfortable with my simulation result of 31.65 s and seeing that this is in line with the Royal Aircraft Establishment result I'm placing my money on Mr Morgan & Morris and their figure of 31.5 s and I will not hold my breath until I see your "proof" for the 21 s claim.

I can add that the C++ code which validity you question (and that I use to come to the same conclusion about the Spitfire turn performance at 20,000 ft as Mr Morgan & Morris of the RAE) is an extension of the code I wrote for my Masters Thesis which was analysis of fighter jet performance and the influence of external stores on speed, climb and turn rate performance etc. This is actually a bit more complicated than analysing the Spitfire by the way since the external stores really mess up the area ruling and leads to complications, especially in the transonic range. However, seeing you are an expert in everything from 100 octane usage during BoB to turn rates I guess this falls far below the level of your extensive expertize.

I also notice that you are now "employed full time in aviation as a pilot" which was interesting to learn because previously, while you have generously shared your experiences and anecdotes of a life as a private pilot, posted pictures of small privare aircraft that you own etc., you have made no earlier mention of this that I recall. Would be interesting to hear which type of aircraft you fly on a commercial basis? Do you fly passenger or cargo services?

While you were quick to question my formal education, I notice that you have still not replied regarding your own credentials. When you do, In addition to the info about when you got your Msc and your experience in the aeronautical industry please add some info about what you did for your Masters Thesis. Based on your penchant and reliance on charts like the NAVWEPS, was it something to do with nomograms perhaps?

[Kurfürst]

So what's your point?

Brag about some C++ analysis of yours of which nobody gives a flying frak...?
Generic harassment of Crumpp because a long time ago he dared to disagree with your opinion?
Assuming a hypothetical identity on the internet as an engineer who have been supposedly intimately involved with the design of Gripen?

This sounds like just a perfectly ordinary internet troll to me.

And again an interesting topic wasted on mutual personal disputes. Why not use the extraordinary pn system to settle your issues with certain people and leave the discussion to those who are genuinely interested in the topic?

[Kurfürst]

Originally Posted by 41Sqn_Stormcrow

And again an interesting topic wasted on mutual personal disputes. Why not use the extraordinary pn system to settle your issues with certain people and leave the discussion to those who are genuinely interested in the topic?

Because the personal dispute is originated in one party's personal frustration and an acute desire for attention and approval.

[Crumpp]

All the data tables and graphs refere to merlin XX equipped aircraft.

The RAE's use of a single chart given the absence of any differientiation between power levels makes perfect sense with the Merlin XX predictions.

The Merlin XX was predicted to maintain similar power from sea level to 20,000 feet.

1020 Hp at Sea Level and 1075HP at 20000 feet:

http://www.enginehistory.org/members...a/Table-04.jpg

http://www.enginehistory.org/members...lysisR-R.shtml

[Holtzauge]

Originally Posted by Kurfürst

So what's your point?

Brag about some C++ analysis of yours of which nobody gives a flying frak...?
Generic harassment of Crumpp because a long time ago he dared to disagree with your opinion?
Assuming a hypothetical identity on the internet as an engineer who have been supposedly intimately involved with the design of Gripen?

This sounds like just a perfectly ordinary internet troll to me.

Troll huh?

I think that criteria fits better on you yourself than anyone else here:

First of all both you posts are totally devoid of any content other than personal attacks. Secondly, you twist words: I have said I have worked on the Gripen, you inserted the word "intimately" to make it seem like I said something else.

And secondly, I'm not assuming any engineering identity or bragging: I responded to a claim by your 100 octane wingman that I "lacked formal education".

I like the psycological assessement in your last post BTW,"is originated in one party's personal frustration and an acute desire for attention and approval"

Talk about pot calling kettle black.......

What Kurfurst neglects to mention is that he holds a grudge since I after several fruitless attempts to him personally was forced to contacted his ISP provider to remove my research material which he without my permission had marked with his own watermark and published on his site.

Now if you have anything constructive to contribute to the issue of 21 versus 31 s turn time for the Spitfire at 20,000ft then add that otherwize you can just bug off and leave the discussion to the grownups.

[Holtzauge]

Originally Posted by Crumpp

The RAE's use of a single chart given the absence of any differientiation between power levels makes perfect sense with the Merlin XX predictions.

The Merlin XX was predicted to maintain similar power from sea level to 20,000 feet.

1020 Hp at Sea Level and 1075HP at 20000 feet:

http://www.enginehistory.org/members...a/Table-04.jpg

http://www.enginehistory.org/members...lysisR-R.shtml

So how does the Merlin XX data you posted above support your 21 s claim?

The Merlin XX is what the RAE refer to in their report R&M 2349 as well. So you both use the same engine data but come to different conclusions.

Why do you agree on the low level results but come to different conclusions for 20,000 ft performance?

Remember the RAE result is that the Spitfire will sustain a loadfactor of n=1.57 (bank angle 51 degress) and turn time 31s at 20,000ft. You get sustainable loadfactor n=2.70 (bank angle 68 degress) and turn time 21s at 20,000ft. Both results refer to the same engine so please explain.

BTW: I note that while you are quick to question other peoples competence and credentials you have not provided anything of substance yourself to back up your claims and it's faily obvious you have nothing to show so I wont press you any more on that.

[Kurfürst]

Originally Posted by Holtzauge

And secondly, I'm not assuming any engineering identity or bragging: I responded to a claim by your 100 octane wingman that I "lacked formal education".

Let's see your diploma then.

Originally Posted by Holtzauge

What Kurfurst neglects to mention is that he holds a grudge since I after several fruitless attempts to him personally was forced to contacted his ISP provider to remove my research material which he without my permission had marked with his own watermark and published on his site.

I don't neglect anything at all, you don't own anything of that paper, and I simply get a feeling of puke when I see posts motivated by your most primitive feelings, the very grudge you wish to attribute to me and your perceivable frustration with life. Grudge can only exist between equals, and so in your case, its despise what I feel.

The papers you have mentioned belong to Stockholm Technical School and you have made unauthorized copies of them from without permission, as you have made it clear in your e-mails (and the fact that later despite numerous request, you refused to name the source), which holds them in their collection. You had become very nervous when I suggested to inquire the place about your activities there and your claim of copyright.

Of your character, it tells me a lot that well until that, you were busy kissing my underside in hope that I'd buy it and fetch some bones for your from my collection. We have traded a few items, and thankfully that's where our contact ended before I would begin to feel filthy.

When that cooperation ended, and your ego was hurt by my posts pointing out your immoral behaviour, you have reacted in the exact manner any dishonest freak would do: attempts at slander at various boards, about your allaged rights to certain papers you took photos off without the permission of their holding archieves.

You have tried to sell that story at various respected aviation communities, at allaboutwarfare.com etc. and other serious aviation sites/forums, where people quickly realized who you are and laughed, in distaste. You then disappeared from all these places, having successfully destroyed your own credibility once and for all. I think the most civilized comment you have received was that your behaviour reveals 'seriously bad taste'.

Your pitiful motive was that I stood up against your constant underhand attack on Crumpp, similar to that behaviour you display here. Your post history reveals that you have only registered here to 'get back' at Crumpp for the humiliating education you have received at his hands previously.

You see, that's exactly what motivates you, an overblown ego of the usual internet troll/nerd, wrapped in pompous sentences, and a made up identity.

Now if you have anything constructive to contribute to the issue of 21 versus 31 s turn time for the Spitfire at 20,000ft then add that otherwize you can just bug off and leave the discussion to the grownups.

Or else what happens you big big grown-up?