Author Topic: Explain this and win the prize! (Read 21998 times)

Crumpp · « **Reply #105 on:** November 08, 2004, 04:32:47 AM »

Quote

The problem is that you have claimed many kind of things in this thread without anykind of proof.

With out any claim? Sorry Gripen, the guys who did those calculations are working aeronautical engineers. Now I don't have the break down on how they arrived at that yet but when the time is right I will.

I am paying for some aeronautical engineering firms to conduct an analysis off the data as it is impartial and much more accurate.

I don't want to discuss anything with you Gripen. You manipulate data and have no credibility.

http://www.hitechcreations.com/forums/showthread.php?s=&threadid=128143&perpage=50&pagenumber=4

Crumpp

gripen · « **Reply #106 on:** November 08, 2004, 05:10:12 AM »

Quote

Originally posted by Crumpp
I don't want to discuss anything with you Gripen.

So why in earth you are in this thread?

This thread is about determining efficiency factor, not about your supposed sources, nor about your supposed book nor about someone's credibility.

Quote

Originally posted by Crumpp
You manipulate data and have no credibility.

Could you point where exactly I manipulate data and how? At least I could not find anything such from your linked page.

Regarding credibility, just look at your own posts in this thread; great logic overall.

Quote

Originally posted by Crumpp
I am paying for some aeronautical engineering firms to conduct an analysis off the data as it is impartial and much more accurate.

Well, If someone is getting something else from the above linked values of the K, you are wasting money.

gripen

Angus · « **Reply #107 on:** November 08, 2004, 05:51:11 AM »

Emmm.
"--------------------------------------------------------------------------------
Originally posted by Crumpp
You manipulate data and have no credibility.

--------------------------------------------------------------------------------"

Just ran over this thread, but can't spot that.
Isn't it getting a tad too hot?

Crumpp · « **Reply #108 on:** November 08, 2004, 07:55:50 AM »

Angus,

You have to look at the evolution of Gripen's flat plate calculations in the thread I linked too. If you don't do the math you won't see it. I don't make those accusations lightly.

Compare his values to the values calculated for ALL the Spitfire Mk IX's for flat plate area. NONE of the Mk IX's have less flat plate area than the FW-190. That was when I realized what was going on.

However the Spitfire Mk VIII does. If you look at Gripens calculations then it becomes clear. That is the main reason I have no interest in continuing any kind discussion with him on this or any subject.

Gripen is a smart guy and has gotten by because many folks don't understand what he is doing.

However, It's not productive nor factual to continue this. It's data manipulated for advantage in a game. It has nothing to do with reality or history.

HTC is being provided with copies of the original reports and can make their own conclusions.

Quote

someone's credibility.

It's all about credibility. You don't have any in my book, Gripen.
I'm sure you will try and throw up some fluff making claims I don't understand your calculations. We both know the truth though.

Crumpp

Angus · « **Reply #109 on:** November 08, 2004, 08:34:47 AM »

Whoops.
I am not an aerodynamic expert, nor have I dipped into this exact thread so much, but it seems as if it may be worth it.
BTW, (silly question, but....gives me a quicker start) How would you best define flat plate area?
The Spitfire VIII and IX are very very similar, with the VIII having a cleaner line (little odds and ends like retractable tailwheel), but no big difference.
At the back of my head I am bothered by the memory of those having a slightly different wing, but I haven't been able to dig this up in my books yet. There could possibly be some difference here?
(I read too much and take too few notes, - well it's a good gymnastic for the brain)
Anyway, letts have a closer look.

gripen · « **Reply #110 on:** November 08, 2004, 08:49:56 AM »

Quote

Originally posted by Crumpp

Compare his values to the values calculated for ALL the Spitfire Mk IX's for flat plate area. NONE of the Mk IX's have less flat plate area than the FW-190.

Well, this has nothing to do with subject of this thread so I moved this back to the original thread.

Quote

Originally posted by Crumpp

It's all about credibility. You don't have any in my book, Gripen.
I'm sure you will try and throw up some fluff making claims I don't understand your calculations. We both know the truth though.

All I see here is that you try to talk about a subject that you don't understand at all. Basicly you are continously throwing in accusations and various claims without anykind of proof.

gripen

Crumpp · « **Reply #111 on:** November 08, 2004, 12:46:37 PM »

I think your getting your values confused and guessing at the German's notations.

Otherwise the FW-190A8 thru FW-190D12 all have the exact same value of K.

Just doesn't hold out when you have the polar plots. The values are different.

That is why I am having the entire windtunnel test report professionally translated. Not because the data on the FW-190V5g will be any good but because it goes into detail on the formulas the Focke-Wulf Design team used.

That tops off the fact you are taking the value of K from the ends of the envelope. One is the best climb speed and the other is top speed in level flight. Look up the definition of best climb speed. It is hardly on the linear portion. Any lower and it's in the stall. The opposite end of that spectrum is top level flight speed.

Now at the low speed end of the envelope the Spitfire will have the advantage in drag.

Crumpp

gripen · « **Reply #112 on:** November 08, 2004, 03:13:12 PM »

Quote

Originally posted by Crumpp
I think your getting your values confused and guessing at the German's notations.

Otherwise the FW-190A8 thru FW-190D12 all have the exact same value of K.

The wing is same and the drag values are different, that's quite logical indeed.

Quote

Originally posted by Crumpp
That tops off the fact you are taking the value of K from the ends of the envelope. One is the best climb speed and the other is top speed in level flight. Look up the definition of best climb speed. It is hardly on the linear portion. Any lower and it's in the stall. The opposite end of that spectrum is top level flight speed.

Total nonsense, the climb Cl at 250-300km/h is around 0,5-0,7 depending on conditions and that's 0,25-0,49 in Cl^2 scale ie clearly in the linear stage. And far from the stall.

gripen

Crumpp · « **Reply #113 on:** November 08, 2004, 05:11:06 PM »

Quote

Total nonsense, the climb Cl at 250-300km/h is around 0,5-0,7 depending on conditions and that's 0,25-0,49 in Cl^2 scale ie clearly in the linear stage. And far from the stall.

You need to learn the definition of best climb speed:

http://www.av8n.com/how/htm/energy.html#fig-power-curve-regimes

Quote

The dividing line between the mushing regime and the front side of the power curve is the highest point on the power curve. At this point, the airplane can fly with the minimal amount of dissipation; this is the “low-rent district”. The airspeed where this occurs is called the best-rate-of-climb airspeed and denoted

It is not in the linear portion of the curve which is:

Quote

The right-hand part of the curve (from moderate airspeeds on up) is called the front side of the power curve. Normal cruising flight is conducted in this range of airspeeds.

The front side of the power curve.

Crumpp

gripen · « **Reply #114 on:** November 08, 2004, 05:38:57 PM »

Quote

Originally posted by Crumpp
You need to learn the definition of best climb speed....

Well, now this is going to be fun, your link has nothing to do with the drag polars nor with the linear stage of the Cd/Cl^2 curve.

The Cl for the climb speed is easy to calculate from the climb speed and theangle of the climb and it does not need to be accurate if it's in the linear stage of the Cd/Cl^2 curve.

If you want to argue, you should prove that the Cl is less than say 0,2-0,3 or more than say 1 at best climb speed; between these values the Cd/Cl^2 curve is about linear.

gripen

Crumpp · « **Reply #115 on:** November 08, 2004, 06:17:31 PM »

Quote

Well, now this is going to be fun, your link has nothing to do with the drag polars nor with the linear stage of the Cd/Cl^2 curve.

Gripen,

My contention is that without the drag polars you are just guessing.

Crumpp

Angus · « **Reply #116 on:** November 08, 2004, 07:58:45 PM »

One little question.
Did you guys ever fly a single engined monoplane yourselves, climbing, banking and so on?
Just curious........

Crumpp · « **Reply #117 on:** November 08, 2004, 08:36:59 PM »

Quote

One little question.

Yep.

Check your email Angus.

Crumpp

gripen · « **Reply #118 on:** November 08, 2004, 10:23:17 PM »

Quote

Originally posted by Crumpp
My contention is that without the drag polars you are just guessing.

Nonsense, the formula:

CwF = Cw0 + K * Ca^2

is directly the drag polar.

Basicly you just continously throw in nonsense arguments.

gripen

Crumpp · « **Reply #119 on:** November 09, 2004, 04:16:21 AM »

Quote

Basicly you just continously throw in nonsense arguments.

What is ridiculus in saying that without the polars you are just guessing?

Besides I will take a trained aeronautical engineer any day over your word especially after seeing your refusal to use Luftwaffe tested data in your calculations.

As long as you:

1. Insist on using the taper ratio of a theoritical ellipse for the Spitfire when every aeronautical engineering student knows the wing twist destroyed the elliptical wet lifting surface of the wing.

2. Do use the drag polars.

Your values will be wrong. Garbage in, Garbage out.

Crumpp