VTOL and Basic Jet fixes (with test mod)

[CaptainTurbomuffin]

After 1.0, jet engines no longer produce a constant thrust. The more speed you have, the more thrust you get. As a result, when trying to make a VTOL, you get the lowest possible thrust. As part of making intakes unique, the currently useless engine nacelle could solve this problem. Just like in real life, the engine nacelle could generate airflow. As a result, with an engine nacelle, you could start with higher thrust, due to the velocity curves. This could also be useful with cruising planes, as you could

take-off and accelerate to your cruising speed faster. For example, if the nacelle provides a mach 1 airflow, your engine's performance will be as good if you were flying at mach 1. After exceeding mach 1, the nacelle becomes useless. (This would mean that you get a constant thrust until mach 1, wich is inappropriate. There could be a slight increase in thrust as the real airflow increases, within mach 1)And the best VTOL engine? The new Basic Jet Engine is really small, it could fit in an 1-m cargo bay *cough* , ( Also, how about an 1 m in-line VTOL container? ) making it an ideal choice for VTOLs, in size. With the nacelle, it should have enough thrust to lift things up. I say it should have at least 90kN thrust, with the nacelle.

Of course, there's a problem. The vel.curves of the BJE are so low that even if the nacelle provides a mach 1 airflow instead of no airflow, you still get a thrust of 84 instead of 70. Based on the Vel.Curves, the max. thrust you can get is 119kN, at mach 1.67. If the vel.curves would give much more thrust, the BJE could have real use. I don't want much. here are the old vel.curves, and the ones I would like to see. (note that I count with 70 as stationary thrust. In theory it's 80, but in practice¹, it won't go over 70. I don't know why, could someone explain this to me?)

I am not suggesting values, I just show an approximate suggestion of something I would like to see.

[TABLE=class: cms_table_grid, width: 128]

[TR]

[TD=width: 64]mach number[/TD]

[TD=width: 64]current thrust[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]0[/TD]

[TD=width: 64, align: right]70[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]0,35[/TD]

[TD=width: 64, align: right]67,2[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]1,05[/TD]

[TD=width: 64, align: right]84[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]1,67[/TD]

[TD=width: 64, align: right]119[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]2,15[/TD]

[TD=width: 64, align: right]77[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]2,3[/TD]

[TD=width: 64, align: right]35[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]2,5[/TD]

[TD=width: 64, align: right]0[/TD]

[/TR]

[/TABLE]

[TABLE=class: cms_table_grid, width: 192]

[TR]

[TD=width: 64]mach number[/TD]

[TD=width: 64]desired thrust (approx)[/TD]

[TD=width: 64]desired thrust with a nacelle (approx)[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]0[/TD]

[TD=width: 64, align: right]70[/TD]

[TD=width: 64, align: right]100[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]0,35[/TD]

[TD=width: 64, align: right]85[/TD]

[TD=width: 64, align: right]105[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]1[/TD]

[TD=width: 64, align: right]120[/TD]

[TD=width: 64, align: right]123[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]1,5[/TD]

[TD=width: 64, align: right]110[/TD]

[TD=width: 64, align: right]113[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]1,8[/TD]

[TD=width: 64, align: right]55[/TD]

[TD=width: 64, align: right]58[/TD]

[/TR]

[TR]

[TD=width: 64, align: right]2[/TD]

[TD=width: 64, align: right]0[/TD]

[TD=width: 64, align: right]0[/TD]

[/TR]

[/TABLE]

Diagram:

As the devs say, they want the BJE to be a subsonic cruising turbofan. Than why it is that it performs better at more than 2 mach than the normal, cruising speed? And that it's the best at mach 1.7? As you can see, I just moved the vel.curves towards a SUBsonic engine, rather than a sonic engine. Also, I ran a few tests in-game¹, and I found out that even if I am an experienced pilot, I could hardly exceed mach 1, using a simple BJE plane. So, if most players can't even exceed mach 1, why do we even have thrust beyond that? A subsonic engine? <...>

If you look at the diagram, you'll see that my suggested values aren't so OP. Than let's have a try! Use my test mod, and try the new BJE yourself! Note that I'm not a modder, and I don't even know much about programming, but I could make a simple mod with these changes. Because I couldn't mod the nacelle thing, there's a second engine, with the nacelled stats. If you are a modder, and you could mod that, feel free to do that.

Conclusion:

-BJE beomes a sub-sonic engine from a sonic engine

-Engine nacelle improves airflow

-No intake air from the nacelle

-No fuel from the nacelle

-Goliath engine with higher starting thrusts, due to the nacelle

---

(Note that this is a copy from my previous balance-thread, but due to the recommendation of an advisor, I'll post its major parts separately.)

Edited September 22, 2015 by CaptainTurbomuffin

[DocMoriarty]

There are a couple more problems with current jet engines and VTOL capability.

1. Reaction Time of Engines

Currently small deltas in thrust setting take as long to process as large deltas. Small deltas should take only a short time to be executed though. The current simulation makes it really hard to precisely fly VTOL's because usually you are overdoing thrust changes due to that behaviour.

2. Changed COM

It's now impossible to create a well balanced VTOL with current jet engines due to the totally superflous and false change of COM of jet engines. COM comes out always way too high. COM isn't even ok for normal airplane building now anymore and completely unintuitive being way outside the model.

The current COM really doesn't make sense, this is what you get when combining intake+nacelle+engine:

Resulting COM in this assembly should be in the center of the nacelle. Turn this vertical and you know why it's impossible to create a well balanced VTOL that looks somewhat non-retarded.

[Stoney3K]

I agree, the response time and CoM of the Wheesley need to be adjusted first (a high bypass turbofan would have a CoM that is further back since the engine core is quite far BEHIND the intake).

Also, for proper VTOL, we need jet RCS nozzles like there are on the Harrier.

[SyberSmoke]

Really for VTOL capability there is one thing that needs to be possible given how the simulation works: Multiple Thrust Control. Simply put, because we are not placing huge engines into a fuselage, we are just placing the nozzles and intakes, the problem could be solved by allowing engine groups. This way one set of nozzles could be set to a +/- range to determine vertical thrust. While the second could be used to control forward motion.

This is the easiest way to make VTOL. As for vectoring nozzles, sure, problem is again control. But instead of power you need to control the pitch of the nozzles...so it still comes down to better control over a number of different engine groups.