Downstream offshore turbine speed (wake velocity)/Fluids

[ankur29]

Hi all,

Homework Statement

estimate the power output of (2 wind turbines, the 1st being 0.6km in front of the second facing the prevailing wind direction witha speed of 20m/s)

Homework Equations

Betz equation:

http://www.wind-power-program.com/betz.htm

Problem with this is that even though you can find the downstream velocity(make it the upstream for turbine in next level) , is that downstream velocity still valid at 0.6Km behind the 1st turbine :S ??


Is there a way of determing an equation that would decribe how velocity would reduce behind the turbine as a function of distance?

Thanks for reading
& happy new year!

 

[Valkarie]

The Betz equation is used to calculate the theoretical maximum power output of a wind turbine, given the wind speed and other factors. Since you are looking at two turbines, you would need to calculate the downstream velocity for each turbine, based on the upstream velocity and the Betz equation. The downstream velocity for the first turbine would be the upstream velocity of the second turbine. The velocity of the wind will decrease with distance from the turbine, but there is no specific equation to describe this. You can make an estimate of the velocity at the second turbine based on the velocity at the first turbine and the Betz equation.