drgondog
Major
Or from Iwo Jima and fight over Tokyo..
Spitfire Mk.XIV vs P-51D Mustang
- Thread starter Soren
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
Or from Iwo Jima and fight over Tokyo..
- Thread starter
- #182
For a specific AoA yes (In this case near the critical AoA at Clmax), but not just for specific velocities, no for all velocities Bill.
The below is the undeniable truth:
If wing A features a Clmax which is 30% higher than that of wing B, the wing area of the two being the same, then Wing A will produce 30% more lift than Wing B at Clmax
Then tell me with numbers where I got the term lift-loading from - that makes about as much sense as what you just said
Bill, I've had heated discussions about wing loading and its importance many times before and it always ends up with all parties using the term lift-loading when relating to turn performance of an a/c, wether it be the right term for the subject or not. I took it to me as I found it an easy and logical way to explain the importance of knowing the Clmax while at the same time showing the true difference between both a/c percentage wise.
Aren't we all ?
drgondog
Major
Then tell me with numbers where I got the term lift-loading from - that makes about as much sense as what you just said
I would not presume to tell you where you got either your notion of lift loading as an 'efficiency' or WL/CLmax as an efficiency or anything else you have said.
Only you can reach for the sources or references
Bill, I've had heated discussions about wing loading and its importance many times before and it always ends up with all parties using the term lift-loading when relating to turn performance of an a/c, wether it be the right term for the subject or not.
Lift loading in the context of manuevering is a perfect way of contrasting Wing Loading to actual aerodynamic loads. Wing loading and Lift Loading are only the 'same' at one G.
I took it to me as I found it an easy and logical way to explain the importance of knowing the Clmax while at the same time showing the true difference between both a/c percentage wise.
QUOTE]
You are free to take anything anyway you want - doesn't mean we (or I agree). You are still avoiding sources and references to show why your brand of 'stuff' regarding dividing WL (or Aerodynamic lift Loading) by CLmax means anything at all.
The one and primary 'efficiency' indicator for a wing is L/D - and you note it is non-dimensional.
- Thread starter
- #184
drgondog
Major
Your post 146 - which started all this
"Wing loading is simply weight divided by wing area, while lift-loading is weight divided by wing area and then divided by the lift coefficient in order to get the true difference. (That is the point of establishing the coefficients, they are efficiency indicators)"
This is nonsense Soren.
Lift loading is the actual lift applied to the wing divided by area as opposed to Weight of airframe divided by the area. If that airplane is in a 3g turn in horizontal plane the Lift Loading is far higher than the airframe weight on the ground - and more than 3x as the total lift and normal forces on the wing are greater than the lift force vector equal and opposite the accelerated mass vector
Further dividing Lift Loading by CL (or CLmax) simply gives you "q" as I have shown you several times. (1/2 rho V^2)[/B]
You go on to speak of 'amateurs' in next paragraph on 146
"Wing-loading, while the prefered way for the amateur to compare a/c, is very misleading for comparative purposes as obviously different wing airfoil designs will perform differently in terms of lift drag production. Dividing the wing-loading with the lift coefficient eliminates the inherent inaccuracy of wing-loading as a comparative method and gives us the lift-loading which is completely accurate as it is based on a proportional efficiency factor established by extensive windtunnel lab test results on the particular wing."
Babble. Lift Loading has zero to do with 'proportional efficiency' or 'proportional efficiency factors'.
"
- Thread starter
- #186
Bill,
I was talking about the lift coefficient, that is an efficiency indicator/factor. I never said lift-loading was an efficiency factor, you're twisting my words.
Here's what I said in post #146 from the very beginning of our discussion:
"Wing loading is simply weight divided by wing area, while lift-loading is weight divided by wing area and then divided by the lift coefficient in order to get the true difference. (That is the point of establishing the coefficients, they are efficiency indicators)"
I don't see how one can translate that into me claiming lift loading is an efficiency factor from this at all. What I am saying however is, like I explained afterwards, that establishing the lift loading is a great of accurately comparing a/c percentage wise.
That is true, and as you can see from my posts I said that as-well;
If I wanted to find the actual lift vs the weight of the a/c then I'd use an entirely different approach as I then need the actual speed of the a/c and the air density of the inviroment it flies in:
Aircraft weight: 4,000 kg
Aircraft wing area: 20 m^2
Speed: 120 m/s
Alt: Sea level
Clmax: 1.50
Lift = Cl * A * .5 * r * V^2
1.5 * 20 * .5 * 1.225 * 120^2 = 264,600 Newtons
264,600 N = 26,981.690 Kgf
26,981.690 Kgf / 4,000 Kg
________________________
= 6.74 G
I never claimed that lift loading was an efficiency indicator or factor, just a way of easily and accurately comparing a/c percentage wise. It is the lift coefficient I say is an efficiency indicator/factor, and it is.
I was talking about the lift coefficient, that is an efficiency indicator/factor. I never said lift-loading was an efficiency factor, you're twisting my words.
Here's what I said in post #146 from the very beginning of our discussion:
"Wing loading is simply weight divided by wing area, while lift-loading is weight divided by wing area and then divided by the lift coefficient in order to get the true difference. (That is the point of establishing the coefficients, they are efficiency indicators)"
I don't see how one can translate that into me claiming lift loading is an efficiency factor from this at all. What I am saying however is, like I explained afterwards, that establishing the lift loading is a great of accurately comparing a/c percentage wise.
That is true, and as you can see from my posts I said that as-well;
If I wanted to find the actual lift vs the weight of the a/c then I'd use an entirely different approach as I then need the actual speed of the a/c and the air density of the inviroment it flies in:
Aircraft weight: 4,000 kg
Aircraft wing area: 20 m^2
Speed: 120 m/s
Alt: Sea level
Clmax: 1.50
Lift = Cl * A * .5 * r * V^2
1.5 * 20 * .5 * 1.225 * 120^2 = 264,600 Newtons
264,600 N = 26,981.690 Kgf
26,981.690 Kgf / 4,000 Kg
________________________
= 6.74 G
I never claimed that lift loading was an efficiency indicator or factor, just a way of easily and accurately comparing a/c percentage wise. It is the lift coefficient I say is an efficiency indicator/factor, and it is.
drgondog
Major
Lift Coeeficient/Drag Coefficient is an efficiency indicator of the wing.
Lift Coefficient is a point on a plot for a specific AoA for a 2-d airfoil section, or a calculated value if Weight, velocity and density, and wing area are known for 1 g steady flight
- Thread starter
- #188
I give up, you only wish to twist and misunderstand what I say, even when I cut it out in cardboard for you.
Don't you even understand that my calculation was for an a/c in a turn ?? Hence the use of Clmax!
What I established in the above calculation was the G-forces a 4,000 kg aircraft with a 20m^2 wing with a Clmax of 1.5 will pull at 120 m/s when doing a max performance turn, which is 6.74 G. A similar a/c with a lower Clmax will only be able to pull less G's, hence why dividing wimg-loading with Clmax is good for comparative reasons as you can then directly compare the turn performance of a/c percentage wise.
That's it for me, I don't wish to continue this anymore as you really don't wish to understand, just preach.
Don't you even understand that my calculation was for an a/c in a turn ?? Hence the use of Clmax!
What I established in the above calculation was the G-forces a 4,000 kg aircraft with a 20m^2 wing with a Clmax of 1.5 will pull at 120 m/s when doing a max performance turn, which is 6.74 G. A similar a/c with a lower Clmax will only be able to pull less G's, hence why dividing wimg-loading with Clmax is good for comparative reasons as you can then directly compare the turn performance of a/c percentage wise.
That's it for me, I don't wish to continue this anymore as you really don't wish to understand, just preach.
kool kitty89
Senior Master Sergeant
Soren, I think the problem is that you still using "Lift loading" in your personal context, while Bill is using the true aerodynamic concept that that term applies to.
(your's is somthing more like lift-corected wing loading, or CLmax corrected wing loading)
I agree though about your original post (about the "efficiency" issue), while I don't think Bill was trying to twist your words, I see how it could be confused. (thought that you were implying "lift loading" was an efficiency figure, though you'd meant the coeficients were efficiency figures)
Also, I think this is the "performance thread" Bill was referring to: http://www.ww2aircraft.net/forum/aviation/bf-109-vs-spitfire-vs-fw-190-vs-p-51-a-13369.html
Given the consistent use of the term "lift loading," I'm surprised this issue hasn't come up before.
(your's is somthing more like lift-corected wing loading, or CLmax corrected wing loading)
I agree though about your original post (about the "efficiency" issue), while I don't think Bill was trying to twist your words, I see how it could be confused. (thought that you were implying "lift loading" was an efficiency figure, though you'd meant the coeficients were efficiency figures)
Also, I think this is the "performance thread" Bill was referring to: http://www.ww2aircraft.net/forum/aviation/bf-109-vs-spitfire-vs-fw-190-vs-p-51-a-13369.html
Given the consistent use of the term "lift loading," I'm surprised this issue hasn't come up before.
drgondog
Major
I didn't 'wish to continue' a long time ago. bye.
Kingfisher
Recruit
- 1
- Sep 19, 2010
My grandfather flew both during the war, as a squadron leader.
He always said the Spit was his first love and that he would rather fly one in a dogfight above any other plane because the all round ability made it most likely to win. Even then, he was shot down in one over Malta by a 109, though his squadron was fighting against huge odds.
But he also loved the P51, which he flew later in the war on long range missions over France. As he said, a Spit couldn't have gone there in the first place and the P51 was still a match for anything the Germans had.
So 2 great aircraft, both top at what they did.
But Grandad ended the war on Tempest Vs chasing V1s and occasionally hunting ME 262s - how he raved about that aircraft!
He always said the Spit was his first love and that he would rather fly one in a dogfight above any other plane because the all round ability made it most likely to win. Even then, he was shot down in one over Malta by a 109, though his squadron was fighting against huge odds.
But he also loved the P51, which he flew later in the war on long range missions over France. As he said, a Spit couldn't have gone there in the first place and the P51 was still a match for anything the Germans had.
So 2 great aircraft, both top at what they did.
But Grandad ended the war on Tempest Vs chasing V1s and occasionally hunting ME 262s - how he raved about that aircraft!
renrich
Chief Master Sergeant
Nice post Kingfisher and dealing with reality rather than sentiment.
Kurfürst
Staff Sergeant
Its necromancy at this stage.
drgondog
Major
It is interesting to hear the anecdotal comparisons from the Brits/RCAF pilots that flew the Spit, the P-51B/D and Tempests. The ones I know all loved all three fighters - for different reasons.
Flt Warren Peglar flew Spits for two years, never enegaged with a german fighter, transferred to USAAF for two months with 355th FG and four air kills plus a ground kill, then transferred back to RCAF flying Tempest V to end the war but did not shoot anything down with Tempest either.
Summary - "Gawd I loved the Spit, loved the Mustang because it was a great fighter but more important - it was great over Germany where I couldn't fight in a Spit, and by the time we were in Tempests on the continent, Jerry was east and I didn't see much of him".
He often wished he could have engaged in a Tempest just to get a relative feel of Tempest vs 190/190 vs his four air kills in a 51B.
BTW Kurfurst - He twice engaaged 109s that he couldn't close on in medium/low speed turning fights - including dropping flaps - but didn't lose ground either. His wingman got the 109s both times - which once again raises the extreme value of pilot skill vs airplnae performance.
Flt Warren Peglar flew Spits for two years, never enegaged with a german fighter, transferred to USAAF for two months with 355th FG and four air kills plus a ground kill, then transferred back to RCAF flying Tempest V to end the war but did not shoot anything down with Tempest either.
Summary - "Gawd I loved the Spit, loved the Mustang because it was a great fighter but more important - it was great over Germany where I couldn't fight in a Spit, and by the time we were in Tempests on the continent, Jerry was east and I didn't see much of him".
He often wished he could have engaged in a Tempest just to get a relative feel of Tempest vs 190/190 vs his four air kills in a 51B.
BTW Kurfurst - He twice engaaged 109s that he couldn't close on in medium/low speed turning fights - including dropping flaps - but didn't lose ground either. His wingman got the 109s both times - which once again raises the extreme value of pilot skill vs airplnae performance.
Kurfürst
Staff Sergeant
Absolutely agree... Yeager said it so well.
that this is fun but a fortress vs. battleship argument? The Spitfire will always be, in any of it's marks, the greatest DEFENSIVE fighter of the Second World War while the P-51, in all IT'S many letters, is the OFFENSIVE fighter that won the war. One must also consider numbers and there is no doubt that had the U.S. 8th ever found a need to bomb England from, let us say, France? There would be so many Mustangs accompanying the bombers that the slightly superior dogfighting Spit Mk14s would be as overwhelmed as were the magnificent FW-190s? My goodness, gentlemen, the Mustang even found a way to get the better of the ME 262, simply by "lingering". One suspects the pilots of those planes to be the difference no matter what Spitfire they would have to ever have "theoretically" faced off against.
Glider
Captain
You are making the huge assumption, that the RAF in this totally different strategic situation would have built the same number of Spitfire XIV. Unlikely I would suggest
Demetrious
Airman 1st Class
- 104
- Aug 22, 2007
No, the problem with the original comparison- in the post that launched this thread, five years ago- was that it was always bunk.
The Spitfire XIV had a Griffon engine- a more advanced powerplant. The P-51D was still using the Merlin. That's why there was 8,000 + P-51Ds made and less then 1,000 Spit XIV's were made- the Griffon was more expensive, and American/British factories were already tooled to produce the Rolls-Royce Merlin in quantity. Many P-51s were needed to escort American daylight bombing, and the D model with the Merlin could already whup any German fighter in the air, so it was pointless to try and re-tool factories to produce Griffons.
The net consequence was that the Spitfire's capabilities jumped ahead of the Mustang's for a time because of production priorities, not any advantage inherent to the airframe. The P-51K would be the proper comparison- at combat weights, too, none of that "let's compare the Spitfire's loaded weight, with 1 hour endurance, to the Mustang with 8 hours of fuel" bunk.
A troll thread still alive five years after it was initiated? Must be a record.
The Spitfire XIV had a Griffon engine- a more advanced powerplant. The P-51D was still using the Merlin. That's why there was 8,000 + P-51Ds made and less then 1,000 Spit XIV's were made- the Griffon was more expensive, and American/British factories were already tooled to produce the Rolls-Royce Merlin in quantity. Many P-51s were needed to escort American daylight bombing, and the D model with the Merlin could already whup any German fighter in the air, so it was pointless to try and re-tool factories to produce Griffons.
The net consequence was that the Spitfire's capabilities jumped ahead of the Mustang's for a time because of production priorities, not any advantage inherent to the airframe. The P-51K would be the proper comparison- at combat weights, too, none of that "let's compare the Spitfire's loaded weight, with 1 hour endurance, to the Mustang with 8 hours of fuel" bunk.
A troll thread still alive five years after it was initiated? Must be a record.
drgondog
Major
Demetrious - I believe you meant P-51H not P-51K as a proper comparison. The only true distingushing difference between D and K was the Hamilston Std vs Aeroproducts prop/pitch controls, whereas the H was lighter, more powerful and essentially a new design.
TheMustangRider
Senior Airman
Drgondog if I'm not mistaken Aeroproduct propellers used in P-51 Ks were a bit troublesome due to some vibrations and some P-51 Ks were fitted the Hamilton Standard used in P-51 Ds. is that correct?
