PLAN Carrier Strike Group and Airwing

Re: J-15 Carrier Multirole Fighter thread

Jeff Head said:

Uh...which is exactly what I said.

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Yes, but the key reason why using ramp to gain vertical velocity is good is because it reduces the induced drag the plane experiences while gaining the vertical velocity.

If there is no reduction in induced drag, then it would make no difference whether the plane gains the vertical velocity by using a ramp, or by pitching up to increase the lift of its own wings, and the ramp would just be dead weight for the ship.

Re: J-15 Carrier Multirole Fighter thread

Engineer said:

And I am telling you it doesn't work that way. Increasing the ramp angle for more upward velocity means reduction in forward velocity. Since lift is a function of airspeed, reduction in forward velocity means a reduction in lift generated, canceling the additional upward velocity. You cannot get extra benefit out of nothing.

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No, no , no ! Lift is not a part of my calculations(I didn't even get to that ) . I will try to explain in simple terms :

Imagine ball rolling down the deck and going to the ramp . Although it has no wings (no lift) it will go up when it leaves the ramp for some time until gravity takes over . Height gained by the ball is a potential energy that would later turn into kinetic energy (speed) when the ball starts descending .

Same principle applies to aircraft . Instead of going slightly down (as on carriers without ramp) it will go upwards and gain some height and time . That height is a potential energy and that time will be used by engines to accelerate aircraft . That is why I said ramp serves as extension of the deck

As for lift - velocity vector point slightly upwards when aircraft leaves ramp , but later it would be more parallel to horizon . With extra time given , engines would accelerate aircraft and enough of the lift will be generated to sustain flight .

P.S.

Watch J-15 with payload from 0:49 . It goes up (vertical component of speed exists) and then continues almost parallel to horizon (vertical component disappears) . But those 2 extra seconds give engines more time to work :

Re: J-15 Carrier Multirole Fighter thread

Also posted in the regular Flanker-tread ... does anyone know for what missile this new huge pylon under both the inner wing-pylons as well as the ones under the intake trunks are for ???

They are very much different to the PL-12-pylons !

Deino

Re: J-15 Carrier Multirole Fighter thread

The former would allow for some 6,5-7 tons of fuel and enough armament. That in itself is still quite a bit, enough for 900-ish km combat radius high flying missions. If that's the worst case scenario like it seems it could be, that's still pretty good.

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For comparisons sake here's a Super Hornet's stats;

Re: J-15 Carrier Multirole Fighter thread

thunderchief said:

No, no , no ! Lift is not a part of my calculations(I didn't even get to that ) .

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Hence why your analysis is flawed.

thunderchief said:

I will try to explain in simple terms :

Imagine ball rolling down the deck and going to the ramp . Although it has no wings (no lift) it will go up when it leaves the ramp for some time until gravity takes over . Height gained by the ball is a potential energy that would later turn into kinetic energy (speed) when the ball starts descending .

Same principle applies to aircraft . Instead of going slightly down (as on carriers without ramp) it will go upwards and gain some height and time . That height is a potential energy and that time will be used by engines to accelerate aircraft . That is why I said ramp serves as extension of the deck

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You completely forgot that the potential energy you spoke of came from the aircraft's kinetic energy in the first place! The ramp itself is completely passive and does not add any energy to the aircraft.

A lot of people think that the ramp shortens the take off length, but the ramp doesn't shorten anything. The take off length is still the same, just that a portion of that length is in the air.

thunderchief said:

As for lift - velocity vector point slightly upwards when aircraft leaves ramp , but later it would be more parallel to horizon . With extra time given , engines would accelerate aircraft and enough of the lift will be generated to sustain flight .

P.S.

Watch J-15 with payload from 0:49 . It goes up (vertical component of speed exists) and then continues almost parallel to horizon (vertical component disappears) . But those 2 extra seconds give engines more time to work :

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If you actually read my previous post, you would have noticed I addressed this very point already.

Re: J-15 Carrier Multirole Fighter thread

A lot of people think that the ramp shortens the take off length, but the ramp doesn't shorten anything. The take off length is still the same, just that a portion of that length is in the air.

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A crude picture and not relevant. We are interested in the length of deck necessary to get aircraft safely into the air, including of course the case with engine failure, because you have to pay for the ship, not for the virtual extension of the take off in front of her. We are also not interested in the take off length to 35 feet above the runway, as you calculate and test for with civilian aircraft, because no trees grow in front of the ship.

Re: J-15 Carrier Multirole Fighter thread

Engineer said:

Hence why your analysis is flawed.


You completely forgot that the potential energy you spoke of came from the aircraft's kinetic energy in the first place! The ramp itself is completely passive and does not add any energy to the aircraft.

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Actually Eng, the ship does provide the first 20 to 30 knots airspeed to the aircrafts kinetic energy in relation to the relative wind, as well as the upward momentum, in addition to the 40 to 60 ft altitude, all with-out the induced drag of the control deflections needed to pitch the aircraft into a positive alpha configuration at a very low airspeed.

There is indeed some induced drag from the additional friction on the tires, and the compression of the main and nose gear struts as the aircraft attempts to accelerate "through" the ramp. So although the ramp is not "free", it is a very good bang for the buck... brat

Re: J-15 Carrier Multirole Fighter thread

A couple of posts of J-15 eye candy for everyone:

Re: J-15 Carrier Multirole Fighter thread

2nd post of J-15 eye candy:


...and here's a couple of CG what we are going to see some day soon:


...and here's one for equation, extolling the virtues of model building.

Re: J-15 Carrier Multirole Fighter thread

Jeff Head said:

A couple of posts of J-15 eye candy for everyone:

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Hope we'll see this on the Liaoning soon.