Leading and trailing edge devices complete aerodynamic simulation is missing

[Maverick Su-35S]

Hello,

 

Since I have been playing with the Su-25T in Lock On FC1, I was able to see that this plane had slats (leading edge fowled devices), but I never tried to investigate how they affect the aerodynamics of that aircraft and later on, on all airplanes in DCS. I am quite surprised to see that even today, even after testing the F-18, which I must confess that after the tests I've done at various AoA and Beta, it is the most well simulated airplane in terms of aerodynamics (better than any other supersonic fighter jet in DCS), reason why I personally congratulate the engineers who worked on it's FM.

 

So far, from all ED modules, ONLY the F-18C correctly simulates an opposite roll due to yaw at negative lift (thing which I've been discussing for years that is missing for both the F-15C and the Su-27/33 also) and also correctly simulates the maximum lift coefficient at around 2.1 at 35 AoA as well as the drag coefficient at around 1.2 close to 90 AoA!

 

But, the droops/slats and flaps that all these aircraft have, only seem to be there as a visual effect without affecting the critical AoA? The F-5 and the F-18 are planes that can fly with the leading edge devices forced in either retracted or deployed position irrespective of flaps position, but even after all these years the critical angle of attack does not vary with neither the leading or the trailing edge devices deflections. The trailing edge down deflections always reduce the critical AoA while the leading edge down devices will always increase the critical AoA. The overall amounts of increase/decrease of the stall AoA should depend on the types of devices being used. The only thing that seems to be simulated is the global Cm (pitching moment coef.) which becomes negative (for symmetrical airfoils) or more negative (for already cambered airfoils). So, only this has been so far simulated regarding the effects of the leading edge devices. I don't know if the drag vs AoA and lift vs AoA functions suffer any changes with leading edge devices deflection. With the trailing edge yes, this occurs, but I can't tell the same for the leading edge ones.

 

Shouldn't the engineers that make flight models know aerodynamics inside out?

 

How could it be that the critical AoA doesn't vary at all with slats/droops and flaps? I'm not the one to tell anyone how this must happen! I do know for myself! It's the obligation of those who make flight models to simulate everything that can be simulated, and this shouldn't be a tremendous task though..., to simulate the critical AoA variation with leading and trailing edge devices.

 

I'm someone believes I don't say the truth, then step out and please correct me and prove that it's otherwise.

 

 

Regards!

Edited December 12, 2018 by Maverick Su-35S
I mistakenly introduced the Su-25 in the context instead of the F-18. Furthermore I completed some details.

[Mr_sukebe]

I’ve got to ask.

I look at the title and you’re making a statement about the aero in game.

Is that because you have evidence, if so, please provide a link.

[Maverick Su-35S]

I’ve got to ask.

I look at the title and you’re making a statement about the aero in game.

Is that because you have evidence, if so, please provide a link.

 

I've got to ask. Are you an aerodynamicist or just someone who's looking for learning through an initial denial? Now seriously, almost everyone who replies to problems found by other people in DCS put the responsibilities upside down. Are you from ED? Are you a flight model engineer? Sorry, but by how you replied you only look like some random guy who knows very little about the subject and dares asking for a proof on normally well known things! The fact that a leading edge device modifies the local AoA and critical AoA are common sense and it would be a painful shame for someone who makes a flight simulator to even question this!

 

ED and their third parties should've "eaten" these principles well in advance before attempting to make a flight simulator.

 

As long as the truth is out there for you and all other ignorant who blindly pretend that DCS is a realistic simulator and before asking someone who spots a problem to provide a link on something that you should've known about (which is definitely not the case through your reply), please do a simple google search on the subject and find out that even the first links that you'll get are the "proof" you're looking for.

 

To re-clarify:

 

The leading edge devices aerodynamic effects are incompletely simulated in DCS. Reason: having them retracted or deployed, there is no effect on the actual AoA, critical AoA and lift. Even the drag doesn't seem to vary during actual simulation (but anyway, before the LE devices drag simulation, the most fundamental are not yet even present). The context and title are plain clear for those who understand what they mean.

Edited July 25, 2018 by Maverick Su-35S