Surprised to see Cliffs of Dover FMs very good considering the age

[taildraggernut]

 

 

Not really nor am I surprised from dealing with you in the past at your behavior.

 

  

 

 

 

Not exactly sure what the point of your mindlessly posting a report that says everything I have already told you.  Probably should read the things guy.  

 

Mindlessly? I posted it because you seem to think blade angle has no effect, the report clearly proves you wrong.

 

 

 

Not only does it discuss the NEGATIVE THRUST produced, it is an early report that discusses possible uses such as controlling the airspeed in a dive and reducing landing distance!

 

NEWSFLASH! beta range has been around for a long time and nobody has disputed the negative thrust effect in reference to making a windmilling prop act 'like' a flat plate, the point remains that you simply got the maths wrong calculating the area of an 11ft prop disc and have no concept that the flat plate effect is very conditional and your theory meets none of those conditions.

Just because you boxed 'negative thrust' in red doesn't mean you know what you are talking about.

 

 

 

It even talks about why you add the disc area to the 1G level reference area.....   hint...that accounts for the shape of the body behind the propeller.

 

Yes, frontal area, not the planform wing area you used.

I provided all the links previously so you could get the maths right.

[Crump]

The math is correct taildraggernut....

 

 

I provided all the links previously so you could get the maths right.

 

That is different theory.  Same result but different theory is all. 

i did not say blade angle has no effect....I said it is negliable and will not change the basic outcome.

 

An aircraft with a windmilling propeller will slow down.  It will NOT speed up some 20 MPH IAS even if you dive it at a significant angle...

 

That is just a fact and how the physics works.

[taildraggernut]

The math is correct taildraggernut....

 

it is not correct , an 11 foot prop can only have the potential frontal area of an 11ft disc, you used the incorrect numbers and came out with the area for a 22ft disc as well as incorrectly using the planform wing area.

 

 

 

That is different theory.  Same result but different theory is all. 

 

Negative, it is the correct physics, god only knows what the stuff is you produced.

 

 

 

i did not say blade angle has no effect....I said it is negliable and will not change the basic outcome.

 

fair enough, you did say that, it is not negligible though and will have a huge effect.

 

 

 

An aircraft with a windmilling propeller will slow down.  It will NOT speed up some 20 MPH IAS even if you dive it at a significant angle...

 

 

an aircraft with a windmilling propeller will have a potential drag force no greater than having an equal diameter solid disc under certain conditions such as blade angle and power produced by the engine, if the propeller is already windmilling and you enter a dive it WILL accelerate.

 

 

 

That is just a fact and how the physics works.

 

not in the real world. it is your own fantasy version of facts and physics.

Edited September 10, 2016 by taildraggernut

[Crump]

 if the propeller is already windmilling and you enter a dive it WILL accelerate.

 

 

 

Oh...run the math...I did!

 

Force vector resolution is a time honored technique of determining aircraft performance.  It is the basis of such things as a climb triangle.

Edited September 10, 2016 by Crump

[taildraggernut]

 

 

Oh...run the math...I did!

 

I know, I'm still laughing at your attempts.

 

  

[SvAF/F16_Goblin]

Actually, can you two please go PM and spare the rest of us your personal p****ng contest, pretty please!

Or, if you are really interested in solving this, go PM and present a common solution and present it in a understandable civil fashion that might make 777/1C listen to you and implement a better mathematical design.

Edited September 10, 2016 by I./ZG1_Goblin

[Hoots]

Actually, can you two please go PM and spare the rest of us your personal p****ng contest, pretty please!

Or, if you are really interested in solving this, go PM and present a common solution and present it in a understandable civil fashion that might make 777/1C listen to you and implement a better mathematical design.

Now look, that kind of logical, sensible, well thought out post just won't do. Whatever next?!

 

[Crump]

 

 

777/1C listen to you

 

They do not support CloD anymore guy.  

 

It is not a "better mathematical design"....All the performance math will end with the same result.  

 

A windmilling propeller creates a ton of drag and will slow the aircraft down.  The fact CloD thru Team Fusion has the Merlin Negative G cut out gaining 20 mph IAS is just not correct.   

 

It is just how the physics works.  

[Crump]

 

 

NEWSFLASH! beta range has been around for a long time and nobody has disputed the negative thrust effect in reference to making a windmilling prop act 'like' a flat plate,

 

So what?

 

 

 

Negative, it is the correct physics, god only knows what the stuff is you produced.

 

Wow, So why don't you work some math?  Oh yeah...you cannot.

 

Anyway, your not understanding vector resolution aircraft performance math reminds me of a developer who once asked, "Does your lift calculation include fuselage lift?"  

 

It is aerodynamics 101 introduction to the lift formula.    It is elegant math that includes everything.  It does not care whether the fuselage is giving lift or the pilot is sticking his arms out the window and flapping his arms.

 

 

 

fair enough, you did say that, it is not negligible though and will have a huge effect.

 

A given amount of force equals a given performance result.  The fact you do not understand vector resolution is irrelevant.

10.9 foot diameter propeller windmilling =  Pi * (10.9)^2 = 373 ft^2 + 242ft^2 wing area = 615ft^2 reference area

 

150 knots level speed 

 

CD at 150 KEAS for a Spitfire Mk 1 = .028

 

Dynamic Pressure = 76.27psf

 

Total Drag produced = CDqS = .028*76.27psf*615Ft^2 = 1313lbs drag force in pounds (or negative thrust because we are not producing any thrust with a windmilling propeller) + 522lbs of drag produced in order to fly at that speed = 1835lbs of drag

 

We are not producing thrust  and are decelerating at a rate of:

 

6050lbs/32.2ft/s^2 = 187.8 Slugs

 

1835lbs / 187.8 Slugs = 9.77ft.

 

Vf = Vi +a*t

 

Vf-Vi = a*t

 

(Vf-Vi)/a = t

 

Vf-Vi = 20 mph or 29fps

 

29fps/9.77ft/s^2 = 2.9 seconds

 

In 2.9 seconds I will lose 20 mph airspeed....

 

Notice in the film my level airspeed never changes once the negative G cut out occurs..

 

so we have to dive in order to speed up...

 

In the film I posted of CloD, I put the nose down about 25 degrees.

 

6050lbs of airplane at a 25 degree dive angle produces 6050lbs * sin25 = 2556lbs of thrust.

 

2556lbs - 1835lbs = 721lbs of thrust

 

721lbs / 187.8 slugs = 3.8 ft/s^2

 

29fps/3.8ft/s^2 = 5.2 seconds of a constant 25 degree angle required to gain 20 mph airspeed.

 

But I do not hold a constant 25 degree angle....so lets ballpark the effects of the angle change.

 

Average angle between 25 degrees and zero is 12.5 degrees

 

6050lbs * Sin 12.5 = 1309lbs of thrust

 

1309lbs - 1835lbs = 526lbs of drag or negative thrust

 

526lbs/187.8 slugs = 2.8 ft/s^2 deceleration

 

The net effect of dipping the nose down to 25 degrees dive angle and coming back up to level flight is equal to decelerating the airplane at 2.8ft/s^2 from its speed the propeller began to windmill in level flight.  In other words, in the 5 seconds the nose was below the horizon, the airplane should have lost about 14 fps or 10 mph from the airspeed I entered.

 

I should NOT have gained 20mph.......

 

That is how the aircraft performance math works and it describes very well the real world results.

 

It is also very easy to see why a Constant Speed Propeller equipped aircraft is very easy to control the airspeed on final approach when you fine pitch the propeller and reduce the manifold pressure....the airplane slows down quite nicely.

[Crump]

 

 

Yes, frontal area, not the planform wing area you used.

 

It is added to the reference area already used to determine the level flight forces at that airspeed.  That is the effect of a windmilling propeller...to act as a flat plate equal to the area of the propeller disc. 

[DD_Arthur]

Don't forget to tell him you're an airline pilot, a janitor and an all round great guy too Crump

[Crump]

Don't forget to tell him you're an airline pilot, a janitor and an all round great guy too Crump

 

 

Thank you!  Maybe you can share some pointers on pokemon or acne medications??

[DD_Arthur]

Thank you!  Maybe you can share some pointers on pokemon or acne medications??

 

Sorry Crump, I'm little too old for that sort of stuff.  I can't believe a janitor of your age and experience is interested in pokemon but judging from the tone of your posts I do believe you might have suffered from some sort of skin condition that has prevented you from participating in normal social intercourse with other human beings.

 

Put the broom down, pull up a chair and tell us all about yourself.  You know you want to.

[Crump]

 

 

Sorry Crump, I'm little too old for that sort of stuff.

 

Obviously you are not so don't dish it out if you cannot take it. 

[taildraggernut]

 

 

Wow, So why don't you work some math? Oh yeah...you cannot.

 

correcting your glaring error at calculating the area of an 11ft prop is enough.

[taildraggernut]

 

 

It is added to the reference area already used to determine the level flight forces at that airspeed. That is the effect of a windmilling propeller...to act as a flat plate equal to the area of the propeller disc.

 

Can you read? you do NOT use the planform wing area. the effect of a windmilling propeller is not to act as if the wings have rotated by 90 degrees.

[6./ZG26_Gielow]

CloD is a stubborn dying dog. Team fusion did a great job and now they should concentrate on creating content for BoS. That would be amazing, wise and fructifying.

Edited September 12, 2016 by 6./ZG26_Gielow

[II./JG27_Rich]

I wouldn't want that at all. Keep BOS the way it is and TF stay with Cliffs of Dover. They're two different games for different tastes

Edited September 12, 2016 by II./JG27_Rich

[Lusekofte]

I think COD will live long and prosper many years, there is currently no signs of it dying, TF 5.0 will make many to fly it again, and make it more popular than ever. I probably fly it more than BOS by that time. To me between those two I have no preference, I gladly fly both

[LLv34_Flanker]

S!

 

 CoD getting Mediterranean is a first in a very long time. Will be interesting. For IL-2 Kuban and Pacific will be good expansions. For sure flying both.

[II./JG27_Rich]

[II./JG77_Manu*]

I think for squad-based flying CloD is clearly ahead of BoS, solely because the limited view distance from BoS prevents real tactical flying.

Hope this gets sorted out in BoS soon. Anyway, good to have 2 such great modern sims at hand, and the variety that goes in hand with it.

Yes modern, Cliffs still looks great, not a tad worse then BoS.

[FuriousMeow]

I think for squad-based flying CloD is clearly ahead of BoS, solely because the limited view distance from BoS prevents real tactical flying.

Hope this gets sorted out in BoS soon. Anyway, good to have 2 such great modern sims at hand, and the variety that goes in hand with it.

Yes modern, Cliffs still looks great, not a tad worse then BoS.

 

You need to stopwith the "limited view distance" - it isn't. It is far enough out that you can "tactically" engage and fight. You just have to use zoom, because unlike some other sim/games the LODs aren't upscaled to make things unrealistically bigger. Zoom in on your PC to the size the cockpit would actually be if you were sitting in it and the visibility is incredibly accurate. The problem is we are playing scaled down due to small monitors, small viewing space, and lack of all around vision.

 

There is zero view distance issue, it's that you don't play with the "zoom" to bring things to 1:1 scale. Objects are rendered up to 9km, that is more than enough for "tactical" engagement - they are just small because of the scale because of the tiny monitors.

 

To "get it sorted" - play at a lower resolution, or get a larger monitor, or start playing with icons. Icons are unrealistic? Not hardcore? Neither is making the LODs artificially larger.

[II./JG77_Manu*]

 

 

It is far enough out that you can "tactically" engage and fight

Wrong

 

 

You just have to use zoom

I do

 

 

and the visibility is incredibly accurate

It isn't

 

 

There is zero view distance issue

there is

 

 

Objects are rendered up to 9km, that is more than enough for "tactical" engagement

 

Plane wrong, you seemingly have no idea about tactical flying. You'd realize it when you'd fly in a squad

 

 

To "get it sorted" - play at a lower resolution, or get a larger monitor, or start playing with icons. Icons are unrealistic? Not hardcore? Neither is making the LODs artificially larger.

That's just nonsense 

[Crump]

 

 

Can you read? you do NOT use the planform wing area. the effect of a windmilling propeller is not to act as if the wings have rotated by 90 degrees.

 

Most certainly you do.

 

Basic formula for determining the drag of a windmilling propeller or turbine fan:

 

Total Drag = Drag + Delta (Change in) Drag

 

Total Drag = Drag(1G level flight = planform wing area) +  Delta (Change in) Drag(Area of the Propeller disc)

 

The wing planform area is the most commonly used reference area and sets the performance at what the aircraft normally does without a windmilling propeller.

 

Not including it would deliver a frankenstein performance estimate.

 

The only "mistake" I made was in the 45 degree calculation because I did not recalculate drag increase after the 20mph.  See, the "reverse thrust" of a windmilling propeller has a direct relationship to velocity.  The faster the aircraft goes, the more drag the windmilling propeller creates.  Our acceleration at a 45 degree  would be less than what I estimated and it would take us considerably longer to accelerate 20mph.

 

 

 

 

 

Average angle between 25 degrees and zero is 12.5 degrees   6050lbs * Sin 12.5 = 1309lbs of thrust   1309lbs - 1835lbs = 526lbs of drag or negative thrust   526lbs/187.8 slugs = 2.8 ft/s^2 deceleration

 

 

But that was just laziness on my part because the point being made by this quick but accurate performance estimate above is very valid and show us the big picture result.

 

It is impossible for the aircraft to gain 20mph during a momentary negative G cutout and the physics presented in CloD is wrong.

 

That is why Spitfire pilots found it far better to roll inverted to follow Bf-109's instead of just letting a negative g cut out occur.....

[sayhitomyshell]

 

Objects are rendered up to 9km, that is more than enough for "tactical" engagement - they are just small because of the scale because of the tiny monitors.

 

 

9km in BoS vs. 14km in Clod on any 1920x1080 monitor....size of monitor doesnt matter.Fact is that 5km difference gives you much more options. Circling around airfield in BoS and looking at several planes taxiing just to see them all disappear second later because you are out of 9 km radius is just wrong.

[taildraggernut]

 

 

Most certainly you do.

 

You do not include planform wing area to the drag produced by a windmilling propeller, only the area of the prop disc and that will be conditional on factors such as blade angle and aircraft speed, in the first instant of a power cut there will be NO windmilling drag but there will be a reduction in induced drag from the pushover. So your basic formula is garbage

 

 

 

Basic formula for determining the drag of a windmilling propeller or turbine fan: Total Drag = Drag + Delta (Change in) Drag Total Drag = Drag(1G level flight = planform wing area) + Delta (Change in) Drag(Area of the Propeller disc)

 

Why would a negative g cut happen at 1g? in a pushover the g is reduced and therefor induced drag, you are trying to argue that the aircraft should suffer the penalty of a level flight engine failure in a dive?

 

 

 

The only "mistake" I made was in the 45 degree calculation

 

and the area of the prop disc in your first line.

 

the simple fact is that in a CS prop system with a momentary loss of power will not make the propeller instantly produce its maximum windmilling drag, the prop would have to be set prior to the power reduction  to its fully fine pitch blade angle to do that (max RPM)

 

 

 

It is impossible for the aircraft to gain 20mph during a momentary negative G cutout and the physics presented in CloD is wrong.

 

No, you are wrong, it is entirely possible to gain 20mph in a dive despite a neg g cutout, it's just simply a case that an injected engine will allow greater speed increase, it only takes a tiny amount of time under speed advantage to gain distance so it's not a case that Spitfires were massively hindered by negative g pushovers it's simply that 109's could utilise the manoeuvre better.

[Crump]

 

 

You do not include planform wing area to the drag produced by a windmilling propeller,

 

Once again....

 

 

 

Basic formula for determining the drag of a windmilling propeller or turbine fan:   Total Drag = Drag + Delta (Change in) Drag   Total Drag = Drag(1G level flight = planform wing area) +  Delta (Change in) Drag(Area of the Propeller disc)   The wing planform area is the most commonly used reference area and sets the performance at what the aircraft normally does without a windmilling propeller.   Not including it would deliver a frankenstein performance estimate.

 

End of Story. 

[Lusekofte]

Well no we got two discussions witch remind me of this...

 

[unreasonable]

I must say I thought that the formula for the area of a circle was Area = Pi times radius squared, not Pi times diameter squared as Crump uses in post 170 when he "does the maths"....... but perhaps Euclid was insufficiently educated.

 

"10.9 foot diameter propeller windmilling =  Pi * (10.9)^2 = 373 ft^2 + 242ft^2 wing area = 615ft^2 reference area"

 

or is it "10.9 foot diameter propeller windmilling = Pi (5.45)^2 = 93 ft^2 + whatever...  ie (373 - 93) = 280 difference in the first term, about 46% of the calculated total assuming the second term is right.

 

When people get the formula for the area of a circle wrong it does rather undermine ones faith in their competence. We all make silly mistakes, however, but the best way to deal with them is to admit them.

[taildraggernut]

 

 

Once again....

 

it's still wrong no matter how many times you quote yourself.

[xvii-Dietrich]

You need to stopwith the "limited view distance" - it isn't.

 

Sorry, but it is.

 

 

There is zero view distance issue, it's that you don't play with the "zoom" to bring things to 1:1 scale.

 

A Ju 88's LotFe telescopic bombsight is fixed FoV. You cannot zoom on it. You are stuck with a set view and a awkward mouse interface to tweak your bomb drop settings and guide your aircraft to target.

 

However, the real issue is the rendering- or view-distance. If you are at 7km alt, then your "see-ahead distance" is hopelessly low. This is why altitude bombing or recon in BoS is impractical, dragging Heinkels and 88s down into a low-level ground attack role. Despite all it's many flaws, CloD remains a superior sim for high-alt level-bombers.

[Lusekofte]

 

 

CloD remains a superior sim for high-alt level-bombers.

 

This is true, when it comes to level bombing COD rules, however there is a cheat witch is making levelbombing a bit easy in COD the black dots witch shows the target miles away. But as you said, there is room for improvements in both games. The rendering of targets in BOS is not adequate for high altitude bombing, the mouse interface for bombsight is a feature I hate.  

[Crump]

Thank you for catching that unreasonable.  What can I say...day 5 of a 5 day after 7.5 hrs of flight and 12 hrs of duty...

 

 

 

We all make silly mistakes, however, but the best way to deal with them is to admit them.

 

 

Maybe you have forgotten the pages of discussion where you tried to convince the forum that engines worked In Accordance With pressure altitude instead of density altitude.  I hope you have cracked the books on mechanical engineering some to grasp the silliness and rather bewildering fact you somehow managed to fill pages of disinformation and confusion ot completely muddy the waters much to the detriment of the community.

 

You have yet to admit that mistake so your whining seems rather disingenuous of you.

 

 

 

 

You do not include planform wing area to the drag produced by a windmilling propeller,

 

Certainly you do....I will explain it once for you.  If you do not get it...well, you can lead a horse to water...

 

 

 

The change in drag is the area of the propeller disc in a windmilling propeller.

 

 

 

Aircraft have a fixed relationship of lift to drag that is unique to that aircraft and fixed by the design.

 

Mathematically that Lift to Drag ratio can be represented in both coefficient form and using the forces.  The relationship is maintained not matter which is used.

 

 

The expression of a windmilling propeller equals:

 

 

D/L = (D + delta D)/L

 

ONE G LEVEL FLIGHT DRAG / ONE G LEVEL FLIGHT LIFT = (ONE G LEVEL FLIGHT DRAG + CHANGE IN ONE G LEVEL FLIGHT DRAG) / ONE G LEVEL FLIGHT LIFT

 

Instead of coefficient form, we can substitute force.

 

D/L = (D + delta D)/L

 

L* D/L ={(D + delta D)/L } *L 

 

D = D + delta D

 

Our total drag = One G Level Flight Drag + Drag of the Windmilling Propeller

 

Reference Area for one G level flight = Wing Area

 

Reference Area for Change in Drag due to Windmilling Propeller = Area of the Propeller Disc

 

Total Drag Reference Area = Wing Area + Area of the Propeller Disc

 

10.9 foot diameter propeller windmilling =  Pi * (5.45)^2 = 93.31 ft^2 + 242ft^2 wing area = 335.3ft^2 reference area

 

150 knots level speed 

 

CD at 150 KEAS for a Spitfire Mk 1 = .028

 

Dynamic Pressure = 76.27psf

 

Total Drag produced = CDqS = .028*76.27psf*93.31Ft^2 = 199.2lbs drag force in pounds (or negative thrust because we are not producing any thrust with a windmilling propeller) + 522lbs of drag produced in order to fly at that speed = 722lbs of drag

 

We are not producing thrust  and are decelerating at a rate of:

 

6050lbs/32.2ft/s^2 = 187.8 Slugs

 

722lbs / 187.8 Slugs = 3.8ft/s^2

 

Vf = Vi +a*t

 

Vf-Vi = a*t

 

(Vf-Vi)/a = t

 

Vf-Vi = 20 mph or 29fps

 

29fps/3.8ft/s^2 = 7.6 seconds

 

In 7.6 seconds I will lose 20 mph airspeed....

You are not going to gain 20 mph airspeed experiencing a Negative G cut out.

 

The physics of a windmilling propeller slow the aircraft down which is why Spitfire pilots rolled inverted to follow Bf-109's instead of simply pushing the stick forward, accepting the negative G cutout and following the German pilots bunt...

it's still wrong no matter how many times you quote yourself.

 

[Edited]

 

Crump we both know where this comes from. KNOCK IT OFF.

[taildraggernut]

 

 

Certainly you do....I will explain it once for you. If you do not get it...well, you can lead a horse to water...

 

Seriously? you now have used the correct method for calculating the area of a circle which is a significantly lower number and yet you still come out with the same end result, you are a master peddler of some of the finest bullshit I have ever witnessed.

 

the drag produced by a windmilling propeller is the same as the drag of a SOLID DISC OF THE SAME DIAMETER not the wing planform.....END OF STORY

[Crump]

the drag produced by a windmilling propeller is the same as the drag of a SOLID DISC OF THE SAME DIAMETER not the wing planform.....END OF STORY

 

 

[Edited]

 

 

http://naca.central.cranfield.ac.uk/reports/1934/naca-report-464.pdf

Edited September 18, 2016 by Bearcat

[taildraggernut]

[Edited]

 

Yes.

 

I don't juggle, If I saw you claiming to juggle but on observation it was apparent that you could not even catch the first ball I would call you out on being incompetent at juggling and I'd be correct  and would not have to demonstrate my own juggling skills, the mere act of holding juggling balls and claiming to be a juggler does not in fact make you a juggler, it does in fact make you a sad juggling wannabe in denial of the truth.

Edited September 18, 2016 by Bearcat

[Crump]

 

 

I don't juggle,

 

You do a good clown routine, though!  

[taildraggernut]

 

 

You do a good clown routine, though!

 

I'm sure you have some sort of Federal agency issued qualification to be able to tell.

[unreasonable]

Thank you for catching that unreasonable.  What can I say...day 5 of a 5 day after 7.5 hrs of flight and 12 hrs of duty...

 

Maybe you have forgotten the pages of discussion where you tried to convince the forum that engines worked In Accordance With pressure altitude instead of density altitude.  I hope you have cracked the books on mechanical engineering some to grasp the silliness and rather bewildering fact you somehow managed to fill pages of disinformation and confusion ot completely muddy the waters much to the detriment of the community.

 

You have yet to admit that mistake so your whining seems rather disingenuous of you.

 

 

That discussion was specifically about whether the 190 supercharger gear change was triggered by pressure altitude or by atmospheric pressure, not "how engines work".

 

Recall please, that when you made your pitch to the developers on this topic, their reply was that the KG uses static pressure to make the change - which is as near as makes no difference atmospheric pressure.

 

So according to the developers, you were wrong - but you continue to repeat this nonsense.