[ShowponyStuart]

I already did an o-grid around this wing (like in the vid)? Plus I have deleted the blocks inside the wing.

[Far]

When you select the blocks inside the wind for o-grid generation, do not select any face.

[ShowponyStuart]

I will give that a go, but I am still trying to figure out why I got those weird results I mention earlier.

There is nothing i this area so i figure it has to be an artifact of the mesh. And its in one of the big blocks in the farfield, I would have been less surprised if it had happened where there was heaps of blocks (inline with the wing but towards the wall opposite the one the wing is attatched too)

So yeah, im real confused.

[Far]

Originally Posted by ShowponyStuart

I will give that a go, but I am still trying to figure out why I got those weird results I mention earlier.

There is nothing i this area so i figure it has to be an artifact of the mesh. And its in one of the big blocks in the farfield, I would have been less surprised if it had happened where there was heaps of blocks (inline with the wing but towards the wall opposite the one the wing is attatched too)

So yeah, im real confused.

Observing flow field without number (cl, cd or whatever variable) will confuse you. Before getting a decent simulation (acceptable mesh, acceptable parameters and convergence) observing merely flow field will mislead you.

At the moment you task should be to get a good mesh. Even after getting numbers I do not look on flow field unless necessary to find reason for some change in data set.

[ShowponyStuart]

I did monitor my cl and cd and while they were roughly in the region I expected them they were not converging as nicely (werent particularly stable)

But the reason I pointed that out, is that there is something wrong with my mesh in the region I thought was good quality. Its almost like there is some solid object or something in that region (looking at streamlines shows them moving around "something"). So im not sure if there are some solid elements that I generated in my mesh by accident or something

So I agree with you completely, Im just trying to figure out why the mesh quality is poor in those areas.

[Far]

wrong mesh in one area may give you problem area in other region as numerical error is accumulating (numerical diffusion etc) due to wrong calculation of flux, thats why I saying do not monitor flow field at the moment. It does not mean you never look on flow field .

Once your mesh is good, most of the problems will go away, believe me . Just put hard work on mesh, as it is the first step to successful simulation.

[ShowponyStuart]

Again I cant fault your logic, and I agree with you completely. I just get a bit flighty sometimes when things arent going right, even if I know im doing the right thing haha.

I think Ive made a small breakthrough with the blocking (given your pointer before.) With any luck I will be back with good news soon.

[Far]

Originally Posted by ShowponyStuart

Again I cant fault your logic, and I agree with you completely. I just get a bit flighty sometimes when things arent going right, even if I know im doing the right thing haha.

I think Ive made a small breakthrough with the blocking (given your pointer before.) With any luck I will be back with good news soon.

After several years in CFD field (that does not make me expert to give advises but I still do ) once your mesh is getting right, your simulation work will make progress at very high pace. During meshing time is flying and one is not making any progress (apparently). Another advantage is that, this experience will help you in next projects, so keep it up and I hope you will get things done.

In meshing (specially blocking) the approach should always be to : one step back and two steps forward instead One step forward, two steps back. (I am in no way a philosopher ). So abandon old blocking and start from scratch and start to build up things and avoid previous mistakes. Also keep in mind the blocking I have attached (DWP2 made by Simon)

[Far]

Just take a look at following threads. It took him around two months or so to get good blocking and mesh (even more as his case very highly complicated but he done it). Really impressive work.

Problems with meshing a 3D wing w/winglet

Problems with meshing a 3D wing w/winglet

[ShowponyStuart]

Havent had a chance to read through those links yet (will do that now) but this is my latest attempt. I think that while the blocking is getting closer to what it should be, there are still a lot of problems.



My latest files too.
https://www.dropbox.com/s/kyykrrqayg...4AOA_mach4.zip

[ShowponyStuart]

Arghhh...Im about ready to give up.

It was all going good...Reasonably nice mesh you say?


..hey that blocking looks reasonably tidy, you might get a mesh with reasonable quality...



Well if you thought that you would be wrong (as was I).


Just thought I was starting to wrap my head around it a bit, but apparently not.
Im going to have to call it quits soon. I could be working on this until after the project is due for all I know. Unless I am hit with some epiphany, or some assurance I can reliably build the mesh quickly by the end of the week, I dont want to waste any more time chasing my tail.

My last set of files for anyone interested
https://www.dropbox.com/s/28fmx3oyyq...OA_mach5_2.zip

[ShowponyStuart]

Is it possible that it is some sort of connectivity issue or something? Or possible due to the way I created the O-grid. (Just selected the wing block and no faces like far suggested.) Perhaps I needed to select the face where the wing connects to the wall?