Free Flight, Free Speech

Posted: **Mon Jul 13, 2020 10:56 am**

This is a simple outer wingtip airfoil.... and I've simplified it as I couldn't face re-identing everything to look inline.

the columns are beta and the row alpha

Code: Select all

   <fcs_function name="T4T/coefficients/wing_right/_7_Cn">
      <function>
         <product>
            <property>T4T/coefficients/airfoil_efficiency</property>
            <property>T4T/damage/wing_right_7</property>
            <property>T4T/aero/Cn_mach_effect</property>
            <table>
               <independentVar lookup="row">T4T/aero/wing_right/_7_AoA-deg</independentVar>
               <independentVar lookup="column">T4T/aero/wing_right/_7_beta-deg</independentVar>
               <tableData>
                        -32     -16     -8     -4     -2      -1    0       1      2      4     8    16    32
                  -90   -1.280 -1.280 -1.280 -1.280 -1.280 -1.280 -1.280 -1.280 -1.280 -1.280 1.280 -1.280 -1.280
                  -32   -0.278 -0.326 -0.350 -0.362 -0.368 -0.371 -0.374 -0.368 -0.362 -0.352 -0.328 -0.282 -0.190
                  -16   -0.379 -0.434 -0.462 -0.476 -0.483 -0.486 -0.490 -0.482 -0.475 -0.461 -0.431 -0.373 -0.257
                  -8   -0.070 -0.069 -0.069 -0.069 -0.069 -0.069 -0.069 -0.069 -0.069 -0.069   -0.069 -0.070 -0.071
                  0     0.540  0.542  0.543  0.544   0.544  0.544   0.544  0.544  0.543   0.542  0.540 0.537   0.529
                  8     1.394  1.395  1.396  1.396   1.396  1.397   1.39    1.391  1.396   1.395  1.393  1.389  1.381
                  16    1.419  1.527  1.581  1.608   1.622  1.628   1.635  1.613  1.594   1.553  1.472  1.308  0.981
                  32    0.476  0.592  0.650  0.679   0.693  0.700   0.708   0.695  0.683   0.657  0.607  0.507  0.306
                  90    1.280  1.280  1.280  1.280   1.280  1.280   1.280   1.280  1.280   1.280  1.280  1.280  1.280
               </tableData>
            </table>
         </product>
      </function>
   </fcs_function>

Posted: **Mon Jul 13, 2020 11:04 am**

mue wrote: And you implicitly set beta = 0.

Can you explain where you see this ?

Posted: **Mon Jul 13, 2020 12:30 pm**

bomber wrote:
mue wrote: And you implicitly set beta = 0.

Can you explain where you see this ?

Thats my understanding and reasoning of the following:

bomber wrote:If you were to cross section the wing following the airstream and compare it with the cross section in the u direction we'd see that the thickness of the airfoil remains constant but the cord length changes with beta either greater or lesser.

I wanted to model that...

...that you "substitute" the original airfoil according to beta into a new airfoil with a new wing section (i.e. with a greater cord length,...). And by that substitution you effectivly put the new airfoil exactly into the airflow direction (i.e. beta = 0).

Posted: **Mon Jul 13, 2020 12:38 pm**

yes then all three co-efficient columns are calculated at their specific zero beta...

but remember I've changed the shape of the airfoil according to the beta angle the 3d wing is experiencing.

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