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Line Rake Analysis

Weight of model in ounces: or in grams:

Wing span of model in inches:

Line diameter in inches:

Number of control lines:

Line length (handle to a/c centerline) in feet:

Wing area in sq. in.:

Lap time in seconds:


Calculations done as follows
(Corrections and improvements solicited!)

  Rho = .002378
  Gravity = 32.17
  Mu = .000157
  E = .85
  CdPe = .01 /*Coefficient of Parasitic Drag */

  WingArea = WingArea / 144.0  /* Get wing area in sq. ft. */

  AspectRatio = ( Span**2 ) / WingArea;

  Velocity = Radius * TwoPI / LapTime  /* Velocity in ft/sec */

  CdL = 1.868 *  (Velocity * Diam / Mu)**-.232 ) *
                 (1.0 - Span * .5 / Radius)**2.768

  Drag = .5 * Rho * (Velocity**2) * WingArea * ( CdPe + ( Weight*Weight /
          ( ((.5*Rho)**2)*(Velocity**4)*(WingArea**2)*PI*AspectRatio*E)) +
        .735 * N * Radius * Diam * CdL / WingArea )

  Gamma = atan ( .686 * Rho * Gravity / Weight * N * Radius * Radius * Diam *
         ((Velocity*Diam/Mu)**-.232)* ( (1.0 - Span*.5/Radius)**2.768) ) * 57.3
 
  LineDrag = .5 * Rho * Velocity*Velocity * .735 * N * Radius * Diam * CdL;   

  LineSweep = Span * 6 * sin(Gamma/57.3)

  ACDrag = Drag - LineDrag

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