Free Flight, Free Speech

With that parenthesis above being done

I'll tell you my design idea, if I understand the first problem we will tackle correctly

We have a wing. And this wing has airfoil shape definitions (the transversal sections). One or more at different locations within 0 (the root==Required) and 1 (the tip)
[ie we could use additional specifications like lets say, introduce one airfoil shape at 0.3, so it knows where to define the airfoil shape (30% from the root towards the tip]. And we could add as many as wanted.

The task of the program is to take these shape definitions in, then output segments desired, assuming lineal extrapolates of the forms through any specified segment. We could say, do something like



Such that the output of the segment function will then create the extrapolates at every quarter of the wing length.

I think that is doable.

Your concern of different points on the wing airfoil spec is valid. This is how I would propose to solve it

• Redefine airfoils by splitting the airfoil data on upper and lower boundaries of the shapes. Such that each of these frontiers is a riemann integrable function
• Using a spline function to smooth the data introduced on each lower and upper (which should be doable as (1) above is true
• Define a series of common points across (0->1), and using the spline determine the location on the airfoil boundaries
• for each cartesian obtained above, assuming lineal decay, determine the location of the point on the following requested segment using the following defined airfoil. (if not defined) then assume it's the same as current
• output all boundaries determined

bomber wrote:Javafoil is designed to model airplane airfoils....

Cant' find it s source code thou. With the source code, maybe we could reimplement it from scratch.

in other words, we would need to know what are the underlying calculations.

ok
maybe we are up to something with xfoil
https://pypi.org/project/xfoil/

Which is GPLed already

We might be able to get the airfoils processed and then xfoiled to get the polars

I suspect all the ducks won't be lined up on day one.... I think that's just the nature of this task.

It might be clunky to start with.... it might require knifing and forking data from one tool into another, simply to get the end to end process understood and then got back and refine modules.

I don't find it onerous to copy and paste data from one tools output into another tools input.... as long as the data's in the correct format from the output to the input, it's where you have to muck about with it that it gets to be a pain.

Simon

yeh xfoils an alternative....

As I said earlier this can be done via the use of other 3d and 2d modeling tools, and a bit of knife and forking.

And I'd forgotten to say I'd already done it for this wing, as it's the Ask13's.

But if you're interested still in solving this using an alternative method, you can have the results I got for comparison if you want ?

Simon

@Bomber
It makes sense to benchmark my method with your outputs, too
Off course!

:_]

IH-COL

Here's the folder

https://drive.google.com/drive/folders/ ... sp=sharing

@Bomber

A Teaser

I think I got somewhere

This video shows the progression of the G535 wing shape as it moves on the span from chord to tip:

VIDEO
DOWNLOAD VIDEO

My output is pushed here,

Can you verify it this is making some sense?
(the csv files are from 1 to 10 given 1 chord -> 10 tip)

IH-COL

this is spot on...

I did a comparison on the output of javafoil of both your polars and the original for the root section... 1

https://drive.google.com/file/d/14kz_Pm ... sp=sharing

the red line is the original the green is yours... the extra polars in yours smooths out the graph, and gives more details negative AoA results

I like it

Simon