DragForce:

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   Calculates maximum drag force acting on a plate-shaped blade.
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   Form:
   [F] = DragForce( d )
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   Inputs
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   d          (1,1)  Data structure
                     .h          (1,1)  Blade height (m)
                     .c          (1,1)  Chord length (m)
                     .v          (1,1)  Speed (m/s)
                     .rho        (1,1)  Fluid density (kg/m^3)

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   Outputs
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   F          (1,1)  Drag force (N)

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   Reference: 

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