how to calculate thrust coefficient, power coefficient and turbulence intensity?

Hello sir, can you please explain how to calculate thrust coefficient, power coefficient and turbulence intensity? 

Thrust coefficient formula is CT = 4a(1-a) equation 32 in wind SAM manual.
How to get the value of unknown variable "a", where a = axial induction factor.

In turbulence intensity formula equation 34, How to get the value of unknown variable "x", where x = cross wind distance between turbines in rotor radii. ??

Can you reply me as earliest as possible please! 

Thanks 

Hi Hamza Ali,

Section 8.2.1 of the SAM wind reference manual describes the code in the turbinePower() function here:

github.com/NREL/ssc/blob/7b84c5b5eb73ab77bc72e081277c6c27a3a00f31/shared/lib_windwakemodel.cpp#L71

Specifically, the thrust coefficient and power coefficient equations are here:

github.com/NREL/ssc/blob/7b84c5b5eb73ab77bc72e081277c6c27a3a00f31/shared/lib_windwakemodel.cpp#L123

The turbulence intensity equations described in Section 8.2.2 are here:

github.com/NREL/ssc/blob/7b84c5b5eb73ab77bc72e081277c6c27a3a00f31/shared/lib_windwakemodel.cpp#L142

Best regards,
Paul.