Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: GhostCDB on September 08, 2014, 01:57:29 PM
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Earlier today Midway was on 200 asked: Why does it seem faster to fly level at 100ft to target and zoom climb to 10k than to auto climb to target and reach 10k.
I am not sure if he can read the forums or if he doesn't have access at all, but it sparked a conversation on 200.
Here is my "attempt" at answering the questions, I am sure there are some better answers out there so if you have it please feel free to comment.
To my understanding, I may be completely wrong, there are airspeeds related to the optimum rate of climbing and they are Vx and Vy. Vx is the airspeed for the best angle of climb and Vy is the airspeed for the best rate of climb with Vx being slower than Vy.
If you climb at Vy it allows you to maximize your altitude gained per minute (time). It enables you to maximize your climb while giving up the least amount of time.
If you climb at Vx it allows you to maximize your altitude gained per kilometer or distance covered. Vx it allows you to maximize your climb while giving up little ground distance and this happens at the speed for the difference between where the thrust (Manifold Pressure) and drag are greatest.
Vx increases with your altitude and Vy decreases with altitude. Vx=Vy at maximum altitude. Which is what 38k in-game, although icepac has "reached" 40k+
http://www.langleyflyingschool.com/Pages/CPGS%204%20Aerodynamics%20and%20Theory%20of%20Flight%20Part%201.html#Drag
I often use that website for school purposes, has a lot of good information available.
Does the game model air density?
Air Density affects lift.
Want more sense out of it, try this site: http://www.grc.nasa.gov/WWW/k-12/airplane/density.html
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Probably because the time it takes to accelerate to the 400kts or so needed to zoom climb to 10k is overlooked.
If you're at sea level, doing 400kts or so, and you zoom climb, yes, you'll make it to 10k faster than if you climbed at Vy. However, from a dead start, or starting at Vy, you'd find that it was faster to climb using Vy. It would take several minutes to accelerate to the airspeed required to do a pure zoom climb to a 10k target altitude... and even then it might still fall short.
Also, keep in mind that zoom climbs are only useful if you can control the aircraft upon reaching your target altitude. So zooming to 10k, only to have your airspeed at 55kts, isn't going to do much good as you're going to stall and have to nose-down, losing altitude, to regain enough airspeed for control. So zooming to 10k in and of itself is relatively worthless, you need to be able to zoom climb and then recover before MCA, or minimum controllable airspeed.
The usefulness of Vy becomes apparent once the above is realized.
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It's faster to climb first because the lighter air density lets you fly faster. If the target is very close it may be faster on the deck but the farther the target the more benefit from climbing first. You also have more energy to use at the target when you come in at altitude.
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It's faster to climb first because the lighter air density lets you fly faster. If the target is very close it may be faster on the deck but the farther the target the more benefit from climbing first. You also have more energy to use at the target when you come in at altitude.
So Air Density is modeled in-game? I know drag is from searching up threads on "Drag Model".
If air density isn't modeled then everything you have suggested is a theory, yes?
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So Air Density is modeled in-game? I know drag is from searching up threads on "Drag Model".
If air density isn't modeled then everything you have suggested is a theory, yes?
Of course density is modeled, either directly, or indirectly via simplified equations for CL-alpha, CD-alpha, etc. vs altitude.
Keep in mind also that engine performance is greatly affected by air density. SL engine performance, as well as the greater lift due to denser air, has a huge impact on SL climb rate.
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What plane can ballistic climb 10k?
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What plane can ballistic climb 10k?
What are you referring to as a ballistic climb? A powerless climb?
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So Air Density is modeled in-game? I know drag is from searching up threads on "Drag Model".
If air density isn't modeled then everything you have suggested is a theory, yes?
:headscratch: Are you suggesting that air density is not ?
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:headscratch: Are you suggesting that air density is not ?
I want density modeled into my CL-alpha curves, but totally omitted from my CD-alpha curves. :D
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So Air Density is modeled in-game? I know drag is from searching up threads on "Drag Model".
If air density isn't modeled then everything you have suggested is a theory, yes?
Next time you're playing check your airspeed gauge. The needle shows IAS and there is a mark showing TAS. Note the increasing difference between IAS and TAS as you gain altitude. Aces High uses std air pressure and adjusts for altitude. The gauges show you the results of air density on lift, drag, and thrust.
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Next time you're playing check your airspeed gauge. The needle shows IAS and there is a mark showing TAS. Note the increasing difference between IAS and TAS as you gain altitude. Aces High uses std air pressure and adjusts for altitude. The gauges show you the results of air density on lift, drag, and thrust.
Yep. This is the reason your TAS can be 400 kts at altitude, yet your plane can stall so easily. Your IAS, the effective airspeed over the wing and control surfaces, is significantly less at altitude.
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I want density modeled into my CL-alpha curves, but totally omitted from my CD-alpha curves. :D
OK Mr. Smartypants :P
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What plane can ballistic climb 10k?
This is all hypothetically speaking, but I believe the Yak3 can and LA7 and of course the 163.
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OK Mr. Smartypants :P
:D
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No, the truth is that the Yak 3 is lighter than air. (And annoying as well.)
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This is all hypothetically speaking, but I believe the Yak3 can and LA7 and of course the 163.
I'm not sure that any of the prop planes in game could pull off a 10k zoom climb from SL, although I do know the F8F held the world record for climb to 10k (from brake release) for 10 years. (94 secs!), so anything is possible with enough power.
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What are you referring to as a ballistic climb? A powerless climb?
Ballistic climb is just a better term for zoom climb. Having a lot of speed and pointing your plane up, exchanging momentum for altitude, rather than just climbing with thrust and lift alone.
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So Air Density is modeled in-game? I know drag is from searching up threads on "Drag Model".
If air density isn't modeled then everything you have suggested is a theory, yes?
I can tell you that air density is definitely modeled in-game. I had a couple of flights this last week that proved it.
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Ballistic climb is just a better term for zoom climb. Having a lot of speed and pointing your plane up, exchanging momentum for altitude, rather than just climbing with thrust and lift alone.
Yeah, thanks for clarifying that for us. :rolleyes:
What your "ballistic climb" accomplishes is a conversion of kinetic energy to potential energy. Momentum is a vector (it has a direction), energy is a scalar. And neither is conserved due to aerodynamic drag. Although laymen use the two terms interchangeably, they're not the same thing.
Now if we can just get those millions of pilots worldwide to stop using that inaccurate "zoom climb" terminology. :rolleyes:
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Ballistic climb is just a better term for zoom climb. Having a lot of speed and pointing your plane up, exchanging momentum for altitude, rather than just climbing with thrust and lift alone.
I believe the term "ballistic" tends to refer to unpowered flight. Zoom climb is likely a better term in this case.
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I believe the term "ballistic" tends to refer to unpowered flight. Zoom climb is likely a better term in this case.
Nope, ballistic climb is a zoom climb. It's just one term is onomatopoic (caveman talk), and the other is more literal, hence better. :P
Floob make plane go zoom now!
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Your only ballistic when your wings are shot off.
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Can some explain how to do a proper zoom climb in combat. I think I read in No Guts No Glory. That a person needs 100 knots on his opponent. And when I do that wich I don't know if it is a zoom climb or not. But I do know I tend to get my but perforated.
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Earlier today Midway was on 200 asked: Why does it seem faster to fly level at 100ft to target and zoom climb to 10k than to auto climb to target and reach 10k.
Before you go into all the conjecture, you may wish to do a simple time test, take off from a field, climb to x alt otw, then level.
And repeat with the level flight first and then the climb.
The key word in that sentence is "SEEM".
HiTech
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Before you go into all the conjecture, you may wish to do a simple time test, take off from a field, climb to x alt otw, then level.
And repeat with the level flight first and then the climb.
The key word in that sentence is "SEEM".
HiTech
Yep. :aok
Here's another angle on this to ponder...
Consider how much time you spend accelerating in that dense seal level air before zoom climbing to altitude, vs a steady climb in rapidly thinning air to altitude. A climb to altitude is a potential energy gain, and trying to gain it first as kinetic energy, at sea level, against drag that increases as a function of velocity ^ 2, and then converting it all at once to potential energy is, well... figure it out.
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Reference to "Ballistic"
Movie: Top Gun
"He's going ballistic" ..... <------ wasn't they referring to their opponent going into a zoom climb?
LOL
TC
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Before you go into all the conjecture, you may wish to do a simple time test, take off from a field, climb to x alt otw, then level.
And repeat with the level flight first and then the climb.
The key word in that sentence is "SEEM".
HiTech
But if I did that my score would suffer :old:
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Btw It suddenly struck me, it may be possible to arrive at the same point faster flying low first and then climbing.
But when arriving at the same point the plane who climbed first would be traveling much faster then the plane who climbed last. And hence have greater energy.
HiTech
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Btw It suddenly struck me, it may be possible to arrive at the same point faster flying low first and then climbing.
But when arriving at the same point the plane who climbed first would be traveling much faster then the plane who climbed last. And hence have greater energy.
HiTech
It's faster to climb first because the lighter air density lets you fly faster. If the target is very close it may be faster on the deck but the farther the target the more benefit from climbing first. You also have more energy to use at the target when you come in at altitude.
:neener:
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Btw It suddenly struck me, it may be possible to arrive at the same point faster flying low first and then climbing.
But when arriving at the same point the plane who climbed first would be traveling much faster then the plane who climbed last. And hence have greater energy.
HiTech
Depends on the plane Dale. As an example (IIRC)...
The F-101 had higher thrust to weight, but the low drag of the F-104 let it accelerate in level flight then zoom climb in steps. The net effect was that the 104 got to altitude quicker. But I think this was the exception, and not the rule for most planes.
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Depends on the plane Dale. As an example (IIRC)...
The F-101 had higher thrust to weight, but the low drag of the F-104 let it accelerate in level flight then zoom climb in steps. The net effect was that the 104 got to altitude quicker. But I think this was the exception, and not the rule for most planes.
With jets HP increase with speed.
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With jets HP increase with speed.
For a given altitude, yes. My point was that the most efficient climb profile can vary from plane to plane. What works best for say, Streak Eagle, would be ridiculous for the U-2. (Though I'd pay cash money to see a U-2 do an immelman right after wheels up :eek: )
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OMG! I have been wrestling with this topic the last three or four days myself. I got so tired up Climbing, Climbing and Climbing and guess what? Only half way there! lol Aghhhhhhhhhhhhhhhhhh!
So I tried going top speed at SL to destination and then nose up. It is sooooooooooooooooooooooo much quicker! And if you try it in 2 steps or 2 levels you can control your plane much better at arrival destination.
Also if you try different planes you might be surprised at which ones actually perform better. :airplane:
Good Luck Everyone
KIMO!
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OMG! I have been wrestling with this topic the last three or four days myself. I got so tired up Climbing, Climbing and Climbing and guess what? Only half way there! lol Aghhhhhhhhhhhhhhhhhh!
So I tried going top speed at SL to destination and then nose up. It is sooooooooooooooooooooooo much quicker! And if you try it in 2 steps or 2 levels you can control your plane much better at arrival destination.
Also if you try different planes you might be surprised at which ones actually perform better. :airplane:
If the distance is long enough, it is clearly more efficient to climb first and then accelerate to top speed. This is because you max level speed is higher at 10k than at sea level, often by quite a margin.
The problem with zooming to 10k is that you arrive there with no speed and therefore a sitting duck in combat. Between arriving low and fast or high and slow (same total energy) I'd take low and fast any day any plane. The most efficient profile for medium/short distances is to climb first then 0-G dive to a combat speed before entering combat.
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Accelerating to top speed @ SL, then zoom climbing to altitude is silly for aircraft of this period (with the notable exception of low drag, low P/W aircraft like the 262). The bulk of your energy expenditure (power) is consumed by drag at high speed. It's far more efficient to climb @ low speed, building as much potential energy (altitude) as you can. But like Bozon says, you need to guarantee that you have sufficient speed when you enter the combat area. I find it useful to climb to say, 2/3 of the desired alt, then establish a shallow, high speed climb going into the fight. You're still building energy, and you're not a slow sitting duck.
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Always climb first if possible. It provides the greatest amount of E (all potential) in the shortest amount of time and is the most efficient use of fuel.
If enemy are in the area retain enough speed to get whatever you're flying over the top of a loop (in case you need to) and put everything else into your climb.
Maximize climb rate until you reach the point at which you can nose down and achieve maximum dive rate for your plane. Now you can choose between speed and climb as you've already maximized potential energy.
As they say... grab alt.
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alt = life
shift x is your friend
or if target alt is 10k...climb to 13k..go lvl for a few seconds then nose dwn to 10k!