DatabaseBoundsError

[Marco]

Hi Cory,

Remember that I had a DatabaseBoundsError, you gave me the tip of using a try-catch and printing out the values that MachUpX was looking for. In my case it said that my reynoldsnumber range was not going low enough. At the time I found it odd because I was quite sure I had the correct range in my database. By now I've got MachUpX running nicely and I think MachUpX makes a mistake with this Error.

I got the DatabaseBoundsError on my root airfoil, with it's chordlength of 1.5meter and with the aircraft expected speedrange the root airfoil reynoldsnumbers are between 1e6 and 4e6.

However MachUpX insists I make the database for the root airfoil as low as Reynoldsnumber 3e4. This is the reynoldsnumber that the wing tip reaches with it's much smaller chordlength.

Also it seems to me that the way xfoil is now called circumvents the rey*mach=12 limit?

as it seems to run correct with more steps. There is also no warning if I use more steps, and I am using no flap deflection.

thanks,

[Cory]

Hi Marco

That's a strange error... Could you privately send me your updated input files once again?

As for the Mach*Reynolds limit, I'm not sure what's going on there. I was able to circumvent that myself last week, surprisingly. I haven't had the time to look into what's actually going on.

Thanks

Cory

[Cory]

Hi Hugo

Could you attach your wing geometry as well? Otherwise we can't run your case.

As for the convergence, you should increase the maximum iterations by a bit. It looks like you've almost converged. Alternatively, you could increase the convergence threshold.

Thanks

Cory

On Tuesday, September 15, 2020 at 9:53:47 AM UTC-6 hugo wrote:

Hello,

I am also having a Database Bounds Error.

I generate the database with airfoil db, using a NACA 2410 cloud point. I have tried various ranges of alpha, Rey,  Mach, I have also tried with scalars for Mach and Rey (default values) but nothing seems to work. I have tried using the database or directly the poly fits from airfoil db but neither works.

Attached are the input files.

Also, I tried with a linear airfoil like in the examples, when I try to run Machup in non linear mode it fails with the following error:

"machupX.exceptions.SolverNotConvergedError: The nonlinear solver failed to converge. The final error was 3.644148802501253e-09."

What am I doing wrong ?

Thanks,

Hugo

[hugo]

Hi Cory,

I sent everything by email.

Thanks,

Hugo

[Cory]

Got it! I'll look at your case when I get some time.

[hugo]

Great, thanks Cory