# Wind Turbine Reynolds number calculation verification

1. Aug 23, 2014

### Big_Dawg

1. The problem statement, all variables and given/known data
Hi guys,

I just wanted to verify my calculation of a reynolds number of a wind turbine. I understand that the reynolds number will vary in a spanwise direction along the blade due to changes in the characteristic length(chord width) and velocity(due to the tip speed ratio). As a way to approximate the reynolds number I've taken an average chord length.

V = 5 (free stream velocity)
lamda = 6 (tip speed ratio)
v* = kinematic visocity of air at 10degrees = 1.4207E-5
l = 0.5 (average chord length)

2. Relevant equations

Re = (V*l)/v*

3. The attempt at a solution

Now this is the part im unsure of. Do I find an average velocity as follows for the calculation:

Vavg = (V*lamda)/2 (Average velocity)

and then calculate as follows:

(Vavg*l)/v* = 527,909

I would appreciate any verification.

2. Aug 23, 2014

### SteamKing

Staff Emeritus
Your calculations should always include units.