"2,5D Wing Calculation"
A calculation method for Xfoil and multi-airfoil wings


* Méthode d'Intégration sur une Aile de Résultats eXpérimentaux & Xfoil
meaning Integral Method over a Wing for eXperimental and Xfoil Results

Go to Miarex download page

Last feature : Coupling MIAReX & Xfoil

Lately I did add a coupling between MIAReX and Xfoil : MIAReX can handle Xfoil calculation. You can automatically generate polars file needed for non linear lifting line calculation.
You can also compute and then display at screen the pressure locally along span.

once the lifting line calculation is converged, local condition are known (local alpha, local Reynolds) at any station along span . Miarex then compute the Cp distribution along chord at this station, and display it. You can then imagine pressure surface generated by the wing airflow.

You can also fill the wing surface with colors corresponding to local CP value.

Here is a page about a program I wanted to have since a while : a program that compute polar for multi-airfoil wing.

Calculation method

   The calculation method used is based on lifting line theory, généralised to non linear behaviour of airfoil section. It computes lift distribution along span, with induced angle for finite wing. Then the program do the sum of local lift Cl, induced and airfoil drag Cdi& Cdairf, and airfoil moment Cm, to get global coefficient Cl, CDI, CDairf, andCM.

   This program is based on formula developed by James C. Sivells & Robert H. Neely in NACA TN-1269 (1947) :

NACA TN-1269, "Method for calculating wing characteristics by lifting-line theory using nonlinear section lift data".

    Those formula were adapted and implemented with Matlab. Ces formules ont été adaptées et mises en place dans un programme écrit en Matlab, et appelé MIAReX pour "Méthode d'Intégration sur une Aile de Résultats EXpérimentaux & Xfoil"

MIAReX Validation

Here are some elements for validation of MIAReX calculation algorithm.

MIAReX calculation example

  1. Rectangular wing calculation

        For a rectangular wing, the chord is constant along span, hence Reynolds number. We may thinks that taking raw 2D data for airfoil behaviour is a fairly good approximation.
       This is not as a good approximation, since allong span the induced angle changes, and then the airfoil local drag. Thanks MIAReX we will evaluate the effect of this 3D phenomenon on the overall performance.

  2. Model Nimbus 4D analysis

    Here is the story of the "aerodynamic tuning" of a small Nimbus 4D model, that had strange behavior. MIAReX was used for wing pitching moment analysis.

    Read more about model Nimbus 4D MIAReX analysis.

  3. Standart Cirrus analysis

    MIAReX was used for illustrating www.cirrusstandard.org web site.

  4. MIAReX & numerical optimization

    Matlab Optimisation toolbox is a very powerful set of numerical optimization routines. The output of Miarex calculation was redirected to those optimisation routines, for precise design cases.

    Read more MIAReX & numerical optimization

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