How to regain lost E? (F4U)

[PuppetZ]

But with our aircraft in this game, none of them have a thrust to weight ratio that gets even close to 1:1 even in full WEP.  Thrust to weight ratio isn't a good metric to use with prop aircraft anyway--that's more of a jet thing.  Power to weight ratio is the metric used to characterize propeller aircraft, and to compute power, you have to account for the BHP at whatever altitude and propeller efficiency.  

Anyway, weight will always be a limiting performance factor with the planes we have in-game.  Every plane in this game will suffer a performance penalty when their weight is increased, and this applies to zoom climbs, turns, whatever...

I get the point. What I wrote was an effort in generalisation to illustrate the principle behind it, not taking into account the specific of ww2 planes and propeller and engine and such that complicate the thing to a point it's hard to grasp.

I'd like to point out though that if you factor propeller efficiency with engine power and other factor I dont even remotly know of, you get a measure of the thrust available at any point in time.

[FLS]

So why does a sailplane fly faster when it's heavier?   

[Stoney]

I get the point. What I wrote was an effort in generalisation to illustrate the principle behind it, not taking into account the specific of ww2 planes and propeller and engine and such that complicate the thing to a point it's hard to grasp.

I'd like to point out though that if you factor propeller efficiency with engine power and other factor I dont even remotly know of, you get a measure of the thrust available at any point in time.

The biggest difference is that jet thrust is constant.  Thrust on propeller aircraft is dynamic, and only remains constant in level, unaccelerated flight.  And, I understood your generalization--the problem is that many people on this board do not and will either (a) not understand or (b) take the generalization and run with it as fact. 

I'm gonna start an Energy thread since this one got so goofy.  I'll start at the very beginning and work through most of this stuff, within the next day or so.

[PuppetZ]

So why does a sailplane fly faster when it's heavier?   

My guess would be, given the same craft, wing area and such only heavier, to generate enough lift you'd have to either have a larger AOA or fly faster. Since an increase in AOA will slow you down, you obviously don't want that. That leave you with nosing slightly more down to fly faster. You would drop faster but at an increased ground speed, thus not affecting too much you glide ratio. Up to the point where you reach maximum airspeed for the particular airframe and have to increase AOA instead shortening your flight time noticably because of increased induced drag.

[PuppetZ]

The biggest difference is that jet thrust is constant.  Thrust on propeller aircraft is dynamic, and only remains constant in level, unaccelerated flight.  And, I understood your generalization--the problem is that many people on this board do not and will either (a) not understand or (b) take the generalization and run with it as fact.  

I'm gonna start an Energy thread since this one got so goofy.  I'll start at the very beginning and work through most of this stuff, within the next day or so.

jet engine thrust is not constant, it burn air just like a piston engine.

The intent of my post was most certainly not to give specific advice regarding how to fly our plane but rather give an overview of the forces at play. People have to think for themselves. I and neither can you, do that for them. But I think I attained my goal of proving that a heavy plane most certainly do not gain anymore thrust from gravity than a lighter one. That assumption is false. That's the laws of physics at work.

I will leave it at that since I'm not willing to write a book on the subject. For those who are interested in expanding their knowledge, I'd refer you to your local library. They usually have a bunch of good physics book you can borrow for free.

 

[2bighorn]

Gravity's acceleration is constant regardless of the mass of the object. On earth it's 9.2m/s. Up to terminal velocity which is affected by the drag imposed by the shape of the specific object. As planes have roughly the same shape, they accelerate at about the same rate at first until they reach a point where drag dictate the final velocity of the fall. If what you said were true, heavier object would fall faster on earth(which has already been proved wrong by experiment). Similarly shaped object will acheive a very close terminal velocity, determined solely by the amount of drag they generate. A steel ball does not fall faster than a wooden one of the same size, even with a big mass differential. Now planes are not inert object, and they usually fly powered so their straight down acceleration rate will be (9.2m/s(gravity constant) + whatever the engine add minus drag). That makes a big difference. And it comes down again to thrust/weight ratio. Why? To answer that, we have to define what is acceleration. Acceleration is a change of velocity along a vector. To change the velocity, you have to apply enough force to overcome inertia. To apply it to powered flight, acceleration is proportionnal to the ability of the engine to overcome the inertia of the mass of the plane(and drag, that's why the faster you go the slower you accelerate. think about the time between 0-100 vs 200-300). Now to understand how this act, we must go back to the basic 4 forces that act on a plane : gravity, lift, thrust, and drag. When flying level, gravity is balanced by lift. When in a climb, some of the engine power is used to fight gravity and the extra lift is used to climb. Now if a plane point straight up, gravity sole opposite force is thrust as the lift vector now point parallel to the horizon. Deceleration rate is a function of (gravity constant - engine thrust - drag). A higher thrust/weight ratio will let you acheive a higher altitude. When thrust/weight ratio exceed 1:1, we have a craft that will accelerate pointing straight up, like a rocket on the launch pad or the space shuttle. Weight is not an advantage nor is it a disadvantage as long as you got a big enough engine to get you moving. A lot of factor come into play but it boils down to the aformentionned 4 forces. 3 of them are dynamic, 1 is not. You cannot change the laws of physics.

Now the question about how this is all modeled in the game is a completely different beast. But with what i've already seen iof the game, I'm sure HTC are already aware of all this.

Weight is a force, F=mg ie mass x gravity acceleration (expressed in simplest way)
When plane dives straight down (points to Earth's center) forces which are accelerating plane are weight and thrust. Opposing force is drag.

Now do the math.

[FLS]

My guess would be, given the same craft, wing area and such only heavier, to generate enough lift you'd have to either have a larger AOA or fly faster. Since an increase in AOA will slow you down, you obviously don't want that. That leave you with nosing slightly more down to fly faster. You would drop faster but at an increased ground speed, thus not affecting too much you glide ratio. Up to the point where you reach maximum airspeed for the particular airframe and have to increase AOA instead shortening your flight time noticably because of increased induced drag.

You're saying the heavier aircraft would go faster for a given glide slope. 

Granted that might change in a zero lift dive and the weight effects are minimized by the engines but you seem to agree with me that increased mass increases the thrust from gravity so the aircraft goes faster over the same distance from the same height.

[PuppetZ]

You're saying the heavier aircraft would go faster for a given glide slope. 

Granted that might change in a zero lift dive and the weight effects are minimized by the engines but you seem to agree with me that increased mass increases the thrust from gravity so the aircraft goes faster over the same distance from the same height.

It need to. the heavier you are the shorter your run get. For a light glider the effect is not large. The heavier you get, the faster you need to be to maintain an optimal AOA. In a glider, the only energy available is alt. You will not end up in the exact same spot.

[PuppetZ]

Weight is a force, F=mg ie mass x gravity acceleration (expressed in simplest way)
When plane dives straight down (points to Earth's center) forces which are accelerating plane are weight and thrust. Opposing force is drag.

Now do the math.

Weight is relative to the acceleration of gravity. Mass is not. It's an absolute measure, function of an object density and volume. Weight and mass are not the same thing, though they are often confounded as such. For proof, take the weightlessness astronaut experience in orbit. They do not feel their weight. Their mass is not canceled. An object in free fall is weightless, not mass less.

When plane dives straight down (points to Earth's center) forces which are accelerating plane are gravity and thrust. Opposing force is drag and inertia(not really a force, rather a tendency to not change state IE : resisting acceleration/deceleration/change in direction). The acceleration granted by gravity is constant. If it's not true then Galileo, sir Isaac Newton and Albert Einstein (and might I add all physicist in between them and up to now) were wrong. I trust they were right. That's science. I know it's against common sense but it's true. Again, and I want it to be very clear, a given plane might dive better than another but it's not because gravity grants it more "thrust". Other factor are the cause. Airframe drag along with total thrust available at any given time determine how fast the plane accelerate through the dive. Gravity is a constant factor regardless of the mass of the plane.

Also I'd like you to define what make a good diver. A nimble zeke which control locks up at 400mph is not regarded as a great diver. A corsair which you can control at past 550 is a good diver. Even then both could accelerate quite well in a dive, one could maintain it longer before it begin shedding parts. I bet the zeke could even get faster. That is once it lost it's wings on the way down. Much less drag without those.

Take 2 good diver. Corsair and P-47. Who wins the race is dependent on how fast their engine can tow them through the dive and the drag generated by their airframe. Gravity is not a factor here because it grants them the exact same bonus to acceleration regardless of their mass. And regardless of the steepness of the dive. The effect on an incline is also the same. Regardless of mass. This one was proved 4 centuries ago by Galileo.

 

[JUGgler]

      I thought this was a game?


  To recover E do this---> "Go diving down" ! 


There's a thread somewhere 



JUGgler

[2bighorn]

Weight is relative to the acceleration of gravity. Mass is not. It's an absolute measure, function of an object density and volume. Weight and mass are not the same thing, though they are often confounded as such. For proof, take the weightlessness astronaut experience in orbit. They do not feel their weight. Their mass is not canceled.

When plane dives straight down (points to Earth's center) forces which are accelerating plane are gravity and thrust. Opposing force is drag and inertia(not really a force, rather a tendency to not change state IE : resisting acceleration/deceleration/change in direction). The acceleration granted by gravity is constant. If it's not true then sir Isaac Newton and Albert Einstein (and might I add all physicist in between them and up to now) were wrong. I trust they were right. That's science. I know it's against common sense but it's true. Again, and I want it to be very clear, a given plane might dive better than another but it's not because gravity grants it more "thrust". Other factor are the cause. Airframe drag along with total thrust available at any given time determine how fast the plane accelerate through the dive. Gravity is a constant factor regardless of the mass of the plane.

Also I'd like you to define what make a good diver. A nimble zeke which control locks up at 400mph is not regarded as a great diver. A corsair which you can control at past 550 is a good diver. Even then both could accelerate quit well in a dive, one could maintain it longer before it begin shedding parts. I bet the zeke could even get faster. That is once it lost it's wings on the way down. Much less drag without those.

 

Ah for Christ's sake. Forget the powered planes.

Take two (in shape and size) identical balls. One is made out of styrofoam and other out of depleted uranium. Drop them from 50,000 ft. Which one will arrive to Earth's surface sooner?

And to make it easier, lets say air density is the same at 50k as it is at seal level.

[PuppetZ]

post removed.

I'll leave it at that

have a nice day sir 

[PuppetZ]

post removed

[Edgar]

I think to get back to the OP's question, how do you regain "E", their is only one answer:

Use your airplanes engine to climb to a higher altitude or use your engine to increase your aircraft's level speed (without losing altitude).

Anything else is trading potential energy for kinetic energy (minus parasitic factors) such as diving, or trading kinetic energy for potential energy (minus parasitic factors) such as a zoom climb. Without atmospheric conditions (such as updraft, etc that are not (often) used in the game), the engine is the only way to bank "E".

<S>
Edgar

[FLS]

It need to. the heavier you are the shorter your run get. For a light glider the effect is not large. The heavier you get, the faster you need to be to maintain an optimal AOA. In a glider, the only energy available is alt. You will not end up in the exact same spot.

Since the thrust increase in this case is proportional to the mass increase you should end up in the same spot excepting a minor difference in induced drag.