Author Topic: Ta152 for Dummies (Read 2075 times)

AeroCat · « **Reply #15 on:** April 21, 2003, 12:44:52 AM »

personaly I dont see how the surface of the wings are effected buy internal weight in any G situation. the weight may (and should) increase the turn radius due to weight and kinetic energy. but I do see where the weight of fuel in the fusalage would effect it. simple physics....

====={X}===== <----- Plane form from front
^^^..............^^^ <----- Lift

either increased lift will rip the wings as well as extra center pressure in the center pushing downward.

anyone remember the basic rules of flight? lift verses weight? the only thing that will happen is the weight in the wings will do is fight the lift the winds themselves are creating. the way you all are talking its the fusalage thats creating lift and the wings are along for the ride.

think about camping trips when you breaking wood for the fire... you can place your hands at both ends and try to break them but as much as you try some of them just wont break. but you apply extra pressure to the center (i.e. your knee) and it will usualy break.

hope this dont confuse anyone.

Badboy · « **Reply #16 on:** April 21, 2003, 05:49:37 AM »

Quote

Originally posted by Wilbus
Emtpying wing tanks first does seam to make them less prone to ripping off. Wether this is right or wrong I am not sure of, it seams right IMO as more weight further away from a solid stable source will give a bigger momentum.

Your conclusion is correct, emptying the wing tanks will make the wings less prone to damage under the same g loading. That is exactly what you would expect in a real aircraft.

When part of an aircraft structure fails, it does so because one or more of its elements have been over stressed due to excessive force. However, the g that we normally refer to is simply a force multiplier. If the TA 152 contained 50lbs in a wing tank, then at 9g that would be an extra 450lbs that would then produce extra bending moments at the wing root, and thus extra bending stress. An aircraft without that additional weight in the wing, would therefore suffer that much less stress and so would not fail under the same g load.

That is why aircraft in the real world have different g restrictions depending on their internal/external stores/weapons configuration. So for example an aircraft with weapons or fuel in or hanging off its wings would be able to pull less g than one in a clean configuration.

Since that is what folk have reported... More Kudos to the Aces High flight/damage model.

Hope that helps.

Badboy

ccvi · « **Reply #17 on:** April 21, 2003, 08:14:10 AM »

Quote

Originally posted by Wilbus
Did you understand me this time or will I have to clearify it even more for you?

Please go ahead, seldom laughed so hard

So far you, and also Badboy, completely missed the point. Discussion isn't about ripping wings when the plane is heavy or light (more or less fuel in the wings), but with changing distribution of the fuel, or bombs attached to the wings vs. fuselage if you want.

I'd like to hear your oppionion about ripping wings with fuselage tanks empty vs. filled up with fuel...

Badboy · « **Reply #18 on:** April 21, 2003, 12:38:21 PM »

Quote

Originally posted by ccvi
So far you, and also Badboy, completely missed the point.

Actually, Duedel made the point that if you used the contents of the wing tanks first, the wings would then be less likely to suffer damage under high g load. That is what you would expect in reality... That was my point.

I haven't addressed any of the other points, or any of the factual errors in other posts, including yours, not because I have missed them, but because I simply choose not to.

Hope that helps.

Badboy

ccvi · « **Reply #19 on:** April 21, 2003, 01:41:17 PM »

Suggesting to drain the wing tanks first implies that during fighting the fuel from the fuselage tanks is beeing used. The alternative beeing to empty the fuselage tanks and use the wing tanks during fighting. That's what this discussion is about.

A plane with more fuel on board breaks easier than one with less fuel. That's true even for fuel in the wings. It's just not worth discussing.

Badboy · « **Reply #20 on:** April 22, 2003, 05:24:34 AM »

Quote

Originally posted by ccvi
It's just not worth discussing.

I think it is always worth discussing issues that can help folk understand concepts that will allow them to play the game better.

It is just a shame that for every message that throws light on a subject, there are several more to confuse it again. I teach this stuff professionally, and even I have to confess that these boards, and the inevitable conflict, can be frustrating.

So long as we all keep talking, I believe everything will work out well.

Badboy

TimRas · « **Reply #21 on:** April 22, 2003, 08:40:10 AM »

Quote

Originally posted by Badboy
Your conclusion is correct, emptying the wing tanks will make the wings less prone to damage under the same g loading. That is exactly what you would expect in a real aircraft.

That is why aircraft in the real world have different g restrictions depending on their internal/external stores/weapons configuration. So for example an aircraft with weapons or fuel in or hanging off its wings would be able to pull less g than one in a clean configuration.

Think it over one more time. The aerodynamic lift tends to bend the wing tips upwards (during positive g manouvres), right?. The weight of the wings, wing fuel, and possible stores tend to bend them down, thus decreasing the total wing root bending moment.

The following link explains cantilevers (which the wings are from the structural point of view):
http://www.brantacan.co.uk/momentsc.htm

This is more academic link of aircraft loads:
http://www.sml.lr.tudelft.nl/education/ae1-019-3/Ch3_part1_int.pdf

RL aircraft have flight restrictions when they carry external stores, but that is because the attachment points have been designed for certain vertical and lateral load factors.

BTW, the Ta152 is not the only AH plane with wing fuel tanks, quite a many have them. If the weakening effect have been modelled it should show in these planes as well.

Badboy · « **Reply #22 on:** April 22, 2003, 11:38:22 AM »

Quote

Originally posted by TimRas
Think it over one more time. The aerodynamic lift tends to bend the wing tips upwards (during positive g manouvres), right?. The weight of the wings, wing fuel, and possible stores tend to bend them down, thus decreasing the total wing root bending moment.

Of course you are absolutely correct... my mistake, and my apologies.

Badboy

ccvi · « **Reply #23 on:** April 22, 2003, 05:20:29 PM »

TimRas, quote from the second link you posted:

"Aircraft condition with empty tanks gives higher bending moment on the wing. This situation develpos during flight (near the end of the flight)" (page 13)

I was tempted to comment that this is (

), as this represented the other far end of possible oppinions (full wings break easier compared to full fuselage vs. empty plane breaks easier than one with full wings), seems to contradict common sense and the "why" wasn't really explained - I guess that's the drawback of many engineering lectures compared to scientific ones (

). After doing some simple calculations i changed my mind.

It turned out that fuel is better kept in the wings than the fuselage - that part I had no doubt about at all (

). Then I compared an empty plane with one that had it's wings filled up with fuel. To my big... huge astonishment (

) the torque bending wings (and later braking them) is reduced by filling up the wing tanks, although increased lift is required.

The pictures on page 11 of your second link seem to show that, though they don't really make it clear (apart from the strange shape). Comparing pictures 1 and 3 there doesn't seem to be a big difference. With an mass increase of 20% put just outside the center of each wing (e.g. bombs) maximum torque at the center (fuselage) decreased to 1/2. Again,

Your pony rips wings too easily? Put bombs on it...

Still,

TracerX · « **Reply #24 on:** April 23, 2003, 02:14:15 PM »

Very good TimRas. I was waiting for someone to make that clear. The other arguments didn't seem right in my mind either.

If you have more weight in the wings, that should help offset the lift component somewhat in a high G turn, making the wings less likely to break, the opposite of what happens when you add weight in the fuselage. Also, good illustration AeroCat. The breaking stick illustration shows what happens when the relative weight of the fuselage is increased over the wings. Now, that is not to say that in AH you will get the same effect. It is likely that unloading the wings will result in stronger wings, just like emptying the aft tank in the 190's results in a more maneuverable airplane. It's a gamey thing.