[0.90]NEAR: A Simpler Aerodynamics Model v1.3.1 12/16/14

[tetryds]

I'm also wondering this too actually.

First you click the FAR button on the top right.

Then disable it on the options:

I guess this is not the right place to be posting this but these mods are from the same author and very closely related so...

[Tex_NL]

With this new information I might actually consider switching from NEAR to FAR. The instantaneous structural failures were the main reason I choose NEAR over FAR..

[smjjames]

I don't care about the spaceplanes all that much, so, I can mostly ignore FAR, and since the structural failures can be disabled, that's great.

[luxyuz]

I haven't had any problems with it. Have you tried limiting angle of attack?

I also like it, saves a heck of a lot on fuel for one, except I'm kind of having two problems:

1. MechJeb doesn't recognize the terminal velocity and lets the rocket go right through without even trying to lower the throttle.

2. Landing in atmosphere doesn't seem very precise with NEAR, I tried to get it to land at the VAB and the KSC launchpad, but it keeps going at least a kilometre off target, same with targeted landings elsewhere. It actually seems to work better without a landing engine, but even then, it was still over a kilometre off target.

I have no problems of angle of attack. A plane can't just fly straight without making thousands of corrections, don't know why.

Now that you mention it, Mechjeb doesn't recognize the terminal velocity and maybe, maybe that's why my rockets wobble and eventually lose control.

If the atmosphere is thinner, obviously Mechjeb can't calculate landings. I think this is a more Mechjeb problem related than NEAR. Mechjeb does not support NEAR.

I really need Mechheb, it took me 3 hours just to build a 3 part station (not that I failed, but I needed lots of tuning in orbit cuz I still haven't unlocked all tech tree for Mechjeb support). I suck at rendezvous and even more at docking! Needless to say, I carry allot of spare fuel and RCS around!

[KerbMav]

So - is NEAR the same as FAR, just with preset options and without fancy graphs and columns?

Also, no, FAR is easier.

Why?

[tetryds]

So - is NEAR the same as FAR, just with preset options and without fancy graphs and columns?

Not really, there is a list with the differences on the OP.

Why?

Easier to reentry with spaceplanes (hyper/supersonic drag), and COL moves back as your mach number rises, increasing stability.

Control surface deflection also changes, which helps.

FAR also has all the graphs so you can tweak your craft, making it easier, IMO.

So, to me FAR is easier for SSTOs and supersonic airplanes, for subsonic planes the difference is not that big, but FAR extras still gets you an enhancement in stability.

It requires more trial and error, and the aerodynamic failures also get in the way, but nothing that increasing wing weight and decreasing control surface deflection can't solve.

NEAR is cool nevertheless.

It's a great first step towards using FAR in the future, without a doubt.

[Jofe]

I got this mod because of another mod that needed either this one or FAR and I'm having this issue where a single solid rocket booster and a capsule will go up to the atmosphere and anything that is more than that is very hard to control. With the single solid rocket booster I end up gaining more than 2km/s of velocity. Any idea of what might be causing this issue?

[tetryds]

I got this mod because of another mod that needed either this one or FAR and I'm having this issue where a single solid rocket booster and a capsule will go up to the atmosphere and anything that is more than that is very hard to control. With the single solid rocket booster I end up gaining more than 2km/s of velocity. Any idea of what might be causing this issue?

Issue?

A booster and a pod has something around 2.6km/s delta v.

So, the stock soupsphere would get rid of most of that but on NEAR the drag forces are much lower.

So, such things are normal

It gets unstable because you have drag force on the tip making it spin over at any slight angle of attack.

Add control surfaces or wing pieces to the bottom of your rockets.

[Jofe]

Just to be sure, its normal then on NEAR for a single RT-10 to send me up around 90-100 km and have an orbital velocity of around 2.5 km/s. Because on stock it sends me up around 20km and gives me a surface velocity of around 450-500 km/s. Its odd for me because the numbers change so much.

[tetryds]

Just to be sure, its normal then on NEAR for a single RT-10 to send me up around 90-100 km and have an orbital velocity of around 2.5 km/s. Because on stock it sends me up around 20km and gives me a surface velocity of around 450-500 km/s. Its odd for me because the numbers change so much.

Yep.

NEAR sends you even further than FAR (cus logic ), as there are no supersonic effects.

Glad that they are overhauling it, now you see why current stock atmosphere is also known as soupsphere.

Edited January 10, 2015 by tetryds

[Jofe]

Yep.

NEAR sends you even further than FAR (cus logic ), as there are no supersonic effects.

Glad that they are overhauling it, now you see why current stock atmosphere is also known as soupsphere.

Guess better find a way to get used to it, it makes weird to do the initial contracts. As said a single rocket booster would get me the first altitude record. On NEAR I get to orbit, or would get if I had better control but that's another story.

Edit: Tried with a liquid fuel booster and must ask if I should use less than 100% thrust, the fuel was consumed sorta fast but I gained a crap ton of velocity.

Edited January 10, 2015 by Jofe

[tetryds]

Guess better find a way to get used to it, it makes weird to do the initial contracts. As said a single rocket booster would get me the first altitude record. On NEAR I get to orbit, or would get if I had better control but that's another story.

Edit: Tried with a liquid fuel booster and must ask if I should use less than 100% thrust, the fuel was consumed sorta fast but I gained a crap ton of velocity.

Yes, always balance your thrust for optimal performance.

[Tochas]

Issue?

A booster and a pod has something around 2.6km/s delta v.

So, the stock soupsphere would get rid of most of that but on NEAR the drag forces are much lower.

So, such things are normal

It gets unstable because you have drag force on the tip making it spin over at any slight angle of attack.

Add control surfaces or wing pieces to the bottom of your rockets.

Hi I am experiencing the same thing but I am not concerned about the height the vessel can get but rather that Deadly Reentry is killing everyone because the pod cannot get below 350m/s while descending a suborbital jump (AP at 40Km) parachutes get burned when deployed and the pod crashes nearly at 500m/s

[JWag]

When I put a pair of fins on this rocket with 2x symmetry, the Center of Lift is in radically different places depending on whether the fins are dorsal and ventral versus when they're port and starboard:

(thumbnail; click for big)

Shouldn't the CoL/CoP be in the same area?

Here's the craft file. The only aero mod I'm using is NEAR, and the only non-stock parts on that rocket are from Procedural Fairings (extended base plus two conical fairing halves). I don't believe the other mods I'm using (KER, KAC, DPAI, Toolbar, Ambient Light, etc.) have any effect on this, but I'll be happy to provide a full list if needed.

[tetryds]

@JWag: always use 3 or more fins.

That is not a bug at all, imagine a plane, if you place the wings on the top and bottom of it, and none on the sides that will not bring the COL back.

So, the editor assumes the pitch axis to place the COL.

On the image on the left you have pitch instability and yaw stability.

On the right you have pitch stability and yaw instability.

So, use 3 or more fins, your rocket will not be stable with only two.

[JWag]

Sorry for my dense-ness. I think I understand what you are saying, but my confusion is why the editor only cares about CoL in pitch, not yaw.

Should I take from this that NEAR doesn't model yaw stability at all? If not, then why not have the editor instead show me the worst-case of pitch and yaw CoL?

[tetryds]

Sorry for my dense-ness. I think I understand what you are saying, but my confusion is why the editor only cares about CoL in pitch, not yaw.

Should I take from this that NEAR doesn't model yaw stability at all? If not, then why not have the editor instead show me the worst-case of pitch and yaw CoL?

It does, it's just that pitch stability is more crucial than yaw stability (most of the plane lift at nominal cruise comes from horizontal wings not rudders )

You get all those in numbers if you use FAR, but it's very simple for planes, just add more tail.

For rockets, fins in all directions.

You can always put your craft sideways too

And it's not worst case scenario or anything, it's just a force sum indicator.

Edited January 11, 2015 by tetryds

[Sirrobert]

So having installed NEAR for my new beta game, I have run into something very weird.

When I started using Mechjeb, my ships started spinning out of control. After doing a few test flights to confirm, I remembered the COL overview, and indeed. Mechjeb throws my COL out of wack ( picture )

My guess is that, in making it massless and dragless to ensure it doesn't matter where you put it on your craft, NEAR turns it into a wing.

So my question is: is there anything I can do about this? I feel like I'm flying blind without atleast 2 mechjeb info windows up

Extra question: What is the new deltaV requirement to get to orbit with NEAR? I noticed it's significantly less, but does anyone have the numbers?

[tetryds]

3300m/s-ish to get to orbit, less than FAR.

I don't think that is wrong at all, the part is creating a lot of drag.

If you are using mechjeb why not use the version that has it inside the probes without requiring any additional parts?

You can also put some wings on the bottom.

[Sirrobert]

I had not concidered that version. Only saw it once, and never used it because I wanted to keep the requirement to unlock new functions.

Thanks for the help, that solves it

[KarnEdge]

Is the "soupsphere" not intended? It seems strange that a RT-10 full fuel with just a command pod going straight up (no gravity turn) can get an apoapsis of 117km using NEAR.

[tetryds]

Is the "soupsphere" not intended? It seems strange that a RT-10 full fuel with just a command pod going straight up (no gravity turn) can get an apoapsis of 117km using NEAR.

Intended, no, but it has a big impact.

Several people think that going so high is even a bug, it's just how a normal atmosphere behaves (nerf the boosters power and you can go even higher).

If you are having issues with it and want to require about the same deltav to orbit just use Isp Difficulty Scaler: http://forum.kerbalspaceprogram.com/threads/52882-0-90-Kerbal-Isp-Difficulty-Scaler-v1-4-2-12-16-14

[oversoul]

I have had the same trouble others are reporting with NEAR and MJ 2.4.2.0-401 causing my rockets to do front flips while "Ascent guidance" is engaged. Quad fins didn't seem to help, nor did the NEAR MJ dll.

So I just started flying my ascents manually. Pain in the d***, but no loop-de-loops.

*UPDATE*

After installing that MJ NEAR .dll, I seem to not be able to right-click on lifting components to see their lift rating?

Edited February 2, 2015 by oversoul

[Crzyrndm]

After installing that MJ NEAR .dll, I seem to not be able to right-click on lifting components to see their lift rating?

In the VAB/SPH part info panels? NEAR and FAR don't use the stock lift rating system so they get removed.

[KerbMav]

Can I just go from FAR to NEAR or will my active save misbehave?