Page 288 - Handbook of Energy Engineering Calculations

torque and axial thrust N if the turbine were operating at 40 r/min and
maximum efficiency.

Calculation Procedure:

1. Compute the air density for this wind turbine
For air, the gas constant R = 287 J/(kg · K). 1 atm = 1.01325 × 10 5

2. Find the total power density in the wind stream

3. Calculate the maximum obtainable power density

4. Compute a reasonably obtainable power density
Assuming η = 40%.

2
(In English units this corresponds to 22.76 W/ft at 22.37 mi/h.)

5. Find the total power produced if the turbine diameter is 120 m

6. What is the torque and axial thrust if the turbine operates at 40 rpm and
maximum efficiency