Vitormouraa

Nope.

In service, yes... but SR-71 could go much higher than the U-2.

No problem at all! The loss of thrust highly depends on the intake design. I said earlier it depends on the engine, that is not correct, but I was referring to the actual inlet design mounted on the TF34. It's difficult to say if it's one or another because that depends on the inlet as I said. The thrust curve will vary, it could decrease or increase. A complex inlet system will try to extract work from the gas at high speeds, with an inlet like the one installed on the A-10 it's really difficult to do the same, if take a look at the fan diameter, you'll see that the inlet is smaller in diameter than the fan itself, making a divergent duct/diffuser, the idea behind this is that, as your aircraft increases the forward speed, the Mass flow and jet velocity tend to increase due to ram effect, but so does the inlet velocity, so the difference between V1 and V2 tends to decrease, but if you decrease the velocity at which the air enters the engine, you can reduce this negative effect, which is called ram drag or inlet momentum drag, loss of thrust due to forward speed. By doing so, you can also recover some of that thrust which was lost. If you had no inlet, this loss would be exponentially high... This is called diffuser (velocity decreases and pressure increases), but this effect is limited due to the extension of the inlet. In my other examples, I explained how supersonic jets will increase the thrust with their C-D inlet designs, and some airframes will increase the thrust beyond the gross thrust (static thrust - on the ground). Again, any time you increase the V1 velocity (air entering the engine), loss of thrust is possible unless you can reduce that speed and extract work from the gas, i.e inlet is also compressing air, doing work for the compressor. A few examples:

Nice! If you read this post, you'll see that thrust in flight varies with speed. So this 'encounter' between the total drag curve and thrust could come much sooner depending on the engine, especially the TF34... Increasing thrust would partially increase your max speed, but you would be wasting so much fuel, energy and money to do that. And on top of that, you'd be dealing with other issues such ass flow separation, coffin corner, compressibility and so on... :thumbup:

The A-10 is designed to be fuel efficient in order to have a good time on station. The A-10 is also designed to be able to carry a lot of weapons (a lot of pylons too, which produce drag) and fly really well at low altitudes and speeds. So there are a series of technical reasons as to why the A-10 is slow, one of them being the A-10 is slow because it has to. If it was designed to fly faster, it probably wouldn't be as good as it is at low/slow. It has big, thick and straight wings which allow the airframe to produce a good amount of lift at slower speeds, big horizontal and vertical stabs also help the nose and rudder authority (survivability as well), big engines, and a not so aerodynamic fuselage. All these things produce a lot of drag, and when combined with not-so-powerful engines, it'll be pretty slow, but the fact that the A-10 is slow does not mean it's a bad thing, it's completely the opposite, it flies extremely well at low/slow, the stall speeds are pretty good, handling, maneuverability and so on. It's supposed to be that way. The most important thing when talking about this though is that, the A-10 is NOT trying to be fast. It's trying to be efficient and stay in the air for a longer time, flying at low altitudes and slower speeds, which is a good thing when giving support to troops on the ground. If it was trying to be fast, it would probably lose all those low speeds characteristics, which is what makes the A-10 a good CAS platform. One reason as to why the A-10 has big engines (which also contribute to drag in some ways - frontal area) is because of propulsive efficiency. Propulsive efficiency is the external efficiency of an engine and is measured in percentage, and this percentage indicates how efficient an engine is at converting the kinetic energy (high speed gases coming out of the exhaust) into making the aircraft flying forward. If the A-10 had to fly fast, you would need an engine that is capable of producing very high speed gases, and to accomplish that you need temperature, and temperature is obtained by an increase in fuel flow (see where I'm getting at?) and ANY time you increase the exhaust gas velocity, the propulsive efficiency is decreased, therefore the engine is less efficient at converting the high speed gases (kinetic energy) into speed. So the engine not only is less efficient, but it's also using more fuel. Since external efficiency is directly related to fuel consumption, hence the big engines on airliners... A high bypass engine is preferable over a low bypass one (that would allow the A-10 to fly faster) because it works with a higher amount of mass flow and a low exhaust gas velocity which helps the propulsive efficiency. In order to fly fast, the exhaust gas velocity must be higher than the speed you want to fly at, and the A-10 wants efficiency instead of speed. As you can see in this chart, a high bypass turbofan engine like the TF34 reaches very good propulsive efficiencies at much, much lower speeds. If you had an afterburning engine, you would need to be supersonic in order to reach these propulsive efficiencies. And that would use tons of fuel... again not exactly what the A-10 is looking for. Turbojets/low bypass turbofans aren't good at slower speeds, because their external efficiency is terrible. So conclusion; the A-10 is slow because of its aerodynamic design which makes it a good low speed/altitude/CAS platform, this aerodynamic design is optimized to be flown at low/slow, and it produces a lot of drag (result from thick and straight wings for example), and the engines are meant to be fuel efficient, so they don't produce enough thrust to overcome that huge amount of drag. Any time you fly faster you waste fuel, which reduces your time on station. Cool fact: 85% of the total thrust produced by the TF34 engine comes from the fan, and not the exhaust. That's why its propulsive efficiency is good. The fan moves a huge amount of mass flow, at a slower speed. The fuel efficiency (S.F.C - internal efficiency, not external) is also very impressive, it's as good as some airliner engines such as the CFM-56, with an S.F.C of 0.371 lbs/lbf/h! It's really good.

-Reduce Size of App Window to 1300x725 Nice!

Having the same issue here, it's crashing/not working properly.

Yes sir, you can PM BIGNEWY, NineLine or Groove.

That is not a good way to calculate thrust since drag is included in the equation. And Drag can be seen as the opposite of thrust, so if the aircraft isn't matching the charts, we don't know if the drag is too high or the thrust is too low. Flying the aircraft at low speeds would impose induced drag (as said above), which is the drag due to lift. In order to maintain a level flight, the aircraft (or the AP) must increase the AoA, which induces drag. Flaps will be extended, slats and so on... Best way to measure thrust as described here, is by using the thrust formula Ms (V2 - V1) / g where Ms is the mass flow, V1 being the entry speed, V2 being the exhaust velocity and G being gravity obviously, but getting these data from the sim is impossible without proper tools or asking to Yo-Yo... that's why those discussions about the TF34 thrust were always stagnated by the lack of info.

I respectfully disagree with GGTharos about the loss of thrust with an installed engine. I have no numbers for the Su-27 and F-15 specifically, but looking at other airframes this number is less 20-15% percent. For example, the F-14 approaches 13% of a difference between installed and uninstalled thrust. SR-71 with 4.5%, A-10 with 1.8%. But all these numbers are pointless since they are different airframes. But I don't think the loss of thrust is that intense. I wouldn't use those numbers as reference, you need to find out the exact difference (installed and uninstalled thrust values), and then use that to prove your point. A general rule of thumb isn't going to help you here. Measuring the thrust in the game is nearly impossible due to the lack of tools. Also what was your speed when testing this out? Forward speed (in this case vertical speed) affects thrust too. I haven't checked the tracks yet, I'll take a look at them later. Discussing this kind of topic is really difficult though, as I said, due to the lack of proper tools to measure thrust, drag and other things. We simply don't know the thrust and drag values. So that's why I believe that flying the aircraft vertically (obtaining altitude and forward speed, which affect thrust dramatically) isn't a good way to find out the installed thrust of the DCS Su-27. And saying you're smarter than everybody here isn't going to help either, that's quite rude, to say the least... Again, I think your posts lack evidence, documents, and real proofs. Not one cares about thinks, guesses or whatever.

Indeed. The augmentor/afterburner color in DCS is not correct. I can confirm that the effects described above are correct. There are a few variables though, but generally speaking, an afterburning engine which has a blue color in the afterburner plume has more oxygen available, the combustion is a little bit more efficient and complete, hence the higher temperatures. The yellowish color you see in the exhaust is a product from an incomplete combustion, partially carbon glowing due to the high temperatures, that's why it appears yellowish. If you can somehow increase the amount of oxygen, perhaps reducing the amount of air being burnt in the combustion chamber, or by increasing the bypass ratio (if there is one), the flame should become more blueish, and hotter. Take a look at an oven and a candle. They burn at different temperatures, the oven is very efficient, burning at a higher temperature, the combustion is more complete, meanwhile, the candle releases soot, due to the incomplete combustion and lower temperatures. Regardless if it's yellow during the day, most of the time it'll be blueish at night. A very cool effect, definitely not very difficult to implement this.

Not sure about that... I don't wanna lose my hearing ability. :)

Hey guys, I've been working on a skin for the Huey and I noticed a few objects that are out of place, but they look completely fine in Photoshop. Why is that? How do I fix this? Here are a few examples, take a look: In-game screenshots In Photoshop screenshots - Keep in mind that some of the stock skins have the same problem, some of them don't. Which makes me think that they were made using different templates?

Indeed. It looks very nice.

The cockpit looks really good. Good job, thanks for the update!

That's awesome!

ATFLIR for sure!

You're overthinking perhaps, they do keep an eye out at the forum, a lot of feedback is sent to ED from here. :)

That would be great. Please nuke me now! :D

I find it very difficult to ignore this thread, I got triggered when people called me sick for dropping a GBU on a civilian town in a video game... if shooting someone wasn't already illegal and immoral. Comparing real life and trying to apply a war crime (from real life) to a game is absurd...

I'm sick because I'm shooting a texture with a shape of a human in a video game. It's sad that this is coming from an ED tester... :doh:

+1

Good stuff!

He just requested a feature, this whole discussion wasn't even necessary.

Why do you care then? So much political correctness over something like that. If it's irrelevant, why are you even here discussing it? When something is irrelevant to me I stay away. This feature won't make you a murderer, just like bombing a civil town won't make you a terrorist, don't be afraid. :)