Over the past day, a series of bug reports on the F-2 have been passed on it’s thrust. And honestly I just, dunno what to think of them. One was on the inconsistency of thrust between the F-16C and the F-2, which would be a buff. And the other was claiming the F-2 uses the NSI intake, which is a nerf.
Yes, the F-2 has a different intake then the F-16C. However, it is not the NSI intake. We know from the developmental papers of the F-2 that it’s intake was based on MCID, however heavily modified.
Yes, it does, at a glance, share a visual similarity with the NSI intake. However it is important to remember it is not an NSI intake, as japan didn’t even buy the research for it (They specifically bought research and intellectual property regarding the block 40, which uses the MCID, as the F-2 was specified to be based on).
I fully agree that the F-2 should technically have a separate thrust curve then the block-40/50, as it does use a separate intake. But it is not NSI, and it should not outright be worse as the bug report claims, with literally zero proof.
The difference in surface area of the intake is like, 0.04m^2. Like that definitely has an impact, but it’s not massive, and I doubt gaijin would model it to actually offset the changed thrust. Also, the person who made the bug report frames it as a nerf at high speeds also, due to “increased channel loss”.
Which like, their reason for thinking it has more channel loss is cause the NSI has a lower mach number. But that like, doesn’t actually just straight up mean it has more channel loss like they claim. A inlet mach number of 0.7 is very desirable so that way compressor blades don’t become transonic. And the compression recovery from slowing the air down is in many ways also beneficial. It’s not a flaw, it’s how it’s designed.
Anyways… Aside from those bug reports. I think I found why integration for the AAM-5 on the F-2 is taking so long.
It appears that the installation of the AAM-5 causes wing vibrations, which, while not harmful enough to reduce the airframe’s life by any amount they find note worthy, does appear to be enough that it makes slaving of the AAM-5 through conventional methods, not viable.
Basically the vibrations mean that the missile may not always be aligned with the airframe in a consistent manner, so they’re having to develop a way to correct for this deviation while still on the rails. Presumably using the missile’s onboard inertial reference system? although I dunno.
So yes, this does prove that the AAM-5 is technically compatible on all F-2’s which got the AMC OFP (as was stated in the AMC OFP upgrade), and the reason they’re not mounted is due to practical limitations, not due to a technical limitation.
Yes that is what I am saying. We knew it should be technically compatible, but that testing was still being carried out, despite the AMC OFP rewrite which added it being over a decade old. This shows why its still undergoing technical validation, when the originally allotted validation period was something like 9 months
The report has not been updated, however, new data on this subject has been passed.
The inlet used on the F-2A is indeed MCID; it’s the MCID -713, which is different from the NSI. My apologies for preliminary data being incorrect. However, it has been corrected. This is also why your source notes it uses the MCID lip. It indeed uses the MCID lip; it uses the lip of the MCID-713.
The MCID-713 inlet uses small-mouth capture geometry like the NSI while having the expanded duct of the MCID-771 (F-16C Block 50 large-mouth inlet). Notably it also has a slightly higher throat Mach number of 0.75. However, maximum inlet airflow remains similar to the NSI, and this is a big limiting factor when paired with the F110-IHI-129 engine. Please note that maximum airflow ties directly to throat area and capture geometry.
Compared to the MCID-771, the MCID-713 offers more stable performance at lower speeds (where the MCID-771 deteriorates) and considerably lower (3% - 4%) drag than the MCID-771.
Upon further investigation, pressure recovery and distortion has been found to be very similar for both inlets at relevant speeds so any possible transonic losses can be discarded without further data. However, the MCID-713 inlet of the F-2A undeniably has slightly superior characteristics to the MCID-771 at lower speeds when air mass flow differences are ignored.
This is not correct. The throat Mach number of the NSI/MCID-713 is more optimised for low speed and static conditions than the MCID-771. It’s essentially the other way around.
±, maximum inlet airflow is undeniably not optimal. However, drag is reduced by a pretty good margin, and losses lessen the closer you get to static thrust. It’s essentially a trade-off. I believe if applied on-top of the F110-GE-129 curve changes, assuming those are also applied to the F-2A, it should still be better than the current aircraft at certain speeds (?) and not as draggy. It’s down to developer implementation and how the data is interpreted, but that’s my take on it. Losses can be rounded down over the standard MCID-713 by optimistically calculating with minor geometry refinements unique to the F-2 in mind as well.
From my reading of it it’ll nerf it towards the very low end speeds where intake mass really matter, but assides from that a slight bump up (relative to the buffed Ge-129 curve from the F-16C buff)? Figuring out the fuel flow rate of the engine should be able to give us figures on when the reduced flow mass truly matters. I wonder if gaijin will actually reduce the drag from it though
Also, something, when I was looking for stuff to disprove it being NSI, i did a bunch of image comparison, and all of it has the inlet being slightly taller then NSI? So it is possible even the flow mass isn’t that different.
The capture geometry on the MCID-713 is ever so slightly different with a mild reverse duct slope. However, the major changes over the NSI are made in the duct where it retains the duct geometry of the MCID-771 and identical lip dimensions are retained otherwise. I do agree that figuring out the fuel flow rate of the engine is important to get a more refined idea of where losses should occur and how much. For the time being a definitive and mapped out lessened drag penalty over the F-16C in regards to the inlet is a nice to have.
The only thing i can find on it’s specific fuel consumption in AB is cm,A = 0.186 kg/Nh, as stated here, but that seems a bit high doesn’t it? Am i doing some math wrong or wouldn’t that be consuming well over 60 kilograms of fuel per second
Multiply by thrust in newtons and divide by 3600. Kilograms of fuel per Newton of thrust per hour. Keep in mind SFC varies with Mach and altitude also. Not sure how this figure compares to in-game.
