Problem Aerodynamics problem with spacecraft3.dll

[Loru]

Greetings

I'm currently developing new craft for Orbiter and I have problem with it.
The craft wold be something like Hermes Shuttle, but I can't tweak aerodynamics parameters for reentry.

I wish it should reentry at about 40-60 deg AoA but in that case the trajectory is terrible and it bounces several times. If it reenters at 80 deg trajectory looks good but control surfaces/RCS are to weak to maintain this AoA. When I simply increase AILERON parameters ship has terrible properties in flight.

here is the ship (requires spacecraft3.dll - not included)
http://www.lorusik.webpark.pl/vertigo.zip

Can someone help me with it?

 

[Donamy]

try banking left or riight at the 40 degree angle to defer some of the lift.

 

[chameleon]

People, i have same problem too.
I cannot write aerodynamics model for capsule of 7K-L1 ship.
Please, can you give me tutorial or another information of aerodynamics in Orbiter?

 

[Thomas Loe.]

For me is possible to fly this bird down to the Runway but i get always a CTD before i can land it.

I found the CG is to far forward its need to adjust more backweard.

Fuel Balast Tanks ?

A light oszillations belong the pitch axis exist depend on the heavy nose can be this dumping on the pitch axis.

With the RCS is possible to hold a 30° up to 45° AOA.

With the Aeroframe is not possible its going down to 15° and a strong oszilations are encounter.

Maybe the Smal elevator ore to mutch movements of the elevator can be the problem, wy the nose coming fast up and down (install a Fly By Wire).

I dont know wy i get a CTD but would be fun to be a test pilot on Orbiter *g*

a good pilot is always in training.
Thomas

 

[Dambuster]

I like it so far - the mesh is really nice!!

A few comments:
I think that the drag coefficient (is this the right term?) is too low - it doesn't seem to slow down anywhere near fast enough for a plane of its shape. If this is fixed, it should help with the AoA during reentry. Also, the RCS/ailerons seem to be too powerful - the roll rate in the atmosphere appears too high. Finally, when I close the bay doors (and to a lesser extent the nose cone), there are still gaps that I can see in the doors.

Thomas: I didn't get any CTDs, but then again when I deorbited and landed I was several thousand miles from any runways . Are you sure it isn't one of your other addons causing the CTD? I had one something like this once where I'd get a CTD once I passed below a certain altitude in reentry.

EDIT: I just tested it again, and this time moved it to Cape Canaveral, flew it to the runway and landed without a CTD. I noticed that it was very difficult to control on the final approach, and the nose kept dropping (NB: I did not use any trim). Also, there seems to be absolutely no control of it on the ground using the RCS/rudder.

 

[Thomas Loe.]

Yes the L/D max is not verry helpfull to reducing speed but i think depends on airfoil NACA its to schape.

But also no speedbreak are installed to help to maintain a good glide profile.


---------- Post added at 02:39 PM ---------- Previous post was at 10:24 AM ----------

The concept of the airfoil should be rework and testing in a Wind Tunnel to find a good solutions.

I think the stabilisers and all deflections and coordinated should be adjusted to find a smooth stable flight ore build a fly by wire for the unstable bird.

A think also to adjust the cord line is to much negative value.

Short Technical Debrief: The Bird in the rentry with max trim in the tail and 35% of fuel was the AOA 10° to 17° with out using the elevator.

And the Dynamic pressure is to high 32 up to 55 but its based on to less AOA.


a good pilot is always in training
Thomas
​

 

[Loru]

Thanks for feedback
Work is still in progress

My spottings:
Animations work fine (no gaps) when using in 0,1 time compression. I think it may be spacecraft 3 issue.

For now I'm reworking mesh (better front and rear gear, speedbrake animation, textures etc.) and learning C++ for writing my own module with 2d panel and simple "hold AOA" autopilot.

I'm also with aerodynamic model but is very hard to fully understand it in English. I have to find some books in polish about it.

Now I'm analyzing DG-IV and shuttle data in order to work something out.

Probably on Saturday there will be an update.