F-16C Fully opened nozzle on MAX AB

[Mudhen1]

So, I realized that most F-16s with GE engines irl open a little bit more than our GE engine in DCS, I'll show you guys a comparison between the real life ones vs DCS. Anyways this is a small thing, and it's my opinion, you don't need to comment anything if you don't agree.

 

[Texac]

Are you in full AB? I'm pretty sure it opens up a lot more if you push the throttle all the way forward.

[Texac]

Now that I look at it I don't think it's fully open, in real life. 

 

[mvsgas]

I have no idea whether in RL or DCS the nozzle open the same amount.

 

What I do know is that 89-2176 from 421 FS at Hill AFB ( at the time of the photo posted by Mudhen1 ) and 88-0170 (posted By Texac)are both block 40, using the F110-GE-100. DCS is suppose to model the F110-GE-129.

I also know that F110-GE-100 at max AB in the ground, nozzle position should be 50 to 70%. In the Air, max AB nozzle pos is 50 to 95%. F110-GE-129: ground 50 to 70%. air 40 to 70% and both engine at high altitude and low speed should be 30 to 50%

 

So, if you go to max AB, Nos Pos can be the same or different every time as long as they are within those limits.

Edited April 7, 2021 by mvsgas

[Mudhen1]

Thanks for the explanation @mvsgas.

[smire666]

Visible at Idle, too. Just try to Idle engine at high speed, than slow down, apply L/G and slow down almost to landing speed. You'll see, the nozzle will open as the speed falls down...

[Geraki]

The  GE or the PW engines does not fully open during AB 

 

 

[Mudhen1]

On 4/8/2021 at 3:38 AM, smire666 said:

Visible at Idle, too. Just try to Idle engine at high speed, than slow down, apply L/G and slow down almost to landing speed. You'll see, the nozzle will open as the speed falls down...

Haha It doesn't work like that, otherwise you would have some issues with the engines or nozzle fully opening for idle at high speed. You can try it yourself in DCS, it doesn't work.

Edited May 6, 2021 by Mudhen1

[Machalot]

I don't have a reference in front of me, but it seems like the nozzle opening should also depend on altitude, Mach, and air temperature. Not solely on the thrust lever setting 

Edited May 6, 2021 by Machalot

[Geraki]

in AB the nozzle does not open 100% 

[smire666]

23 hours ago, Mudhen1 said:

Haha It doesn't work like that, otherwise you would have some issues with the engines or nozzle fully opening for idle at high speed. You can try it yourself in DCS, it doesn't work.

 

Man, try it, first

[Machalot]

53 minutes ago, deadpool said:

 

The reasoning for why the nozzle was opening and not going for a more optimal constricted form that I have heard is that this would cause pressure and more importantly temperatures to climb too high inside the engine.

Sounds plausible. There are theoretically ideal area ratios for converging-diverging nozzles, but material thermal limits probably constrain the practical nozzle schedule. 

[Mudhen1]

On 5/7/2021 at 7:07 AM, smire666 said:

Man, try it, first

Sure I did, awhile ago, even now if you go IDLE at a high speed you won't get the open nozzle, even if it did there would be no AB, it just doesn't make sense for me.

[smire666]

11 hours ago, Mudhen1 said:

Sure I did, awhile ago, even now if you go IDLE at a high speed you won't get the open nozzle, even if it did there would be no AB, it just doesn't make sense for me.

Sry, I´m not sure, we´re talking about the same. If I idle the engine at high speed, nozzle remains closed. As the plane slows down, first then the nozzle begans open. It corresponds to the @deadpool´s post.

[Frederf]

The engine is essentially FADEC. If you're very fast and put the handle in idle the engine will still run at MIL until the speed drops a bit. Pilot in F-16 gets a "vote" but he doesn't directly control the airplane.