PROFILE CURVES

 

Lift coefficient "Cl" is shown at at the vertikal axis. There are three curvers with differnet Reynolds (Re) numbers.

Roughly :..Re = 70.000 x "V res" x Cord .....("V res" ..."Chord")

Ian cummings does a 2 blader, and they are always fast i.e. a high Re-numners. So in this case you should choose the Re 150.000 curve

 

Draw a straight line from the 0-point of the system to the tangetial point of the appropriate Re-curve. Vertically from this tangential point you find the "Cl" value you need at the Y-axis.

 

The above curves represent the NACA 2412 profile that Ian Cummings is going to use. The "Cl" value in this case is 0.85