Introducing 

Prezi AI.

Your new presentation assistant.

Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.

Loading…
Transcript

Betz's Law

Presented by Soheil Darvishi

Intro

Intro

Albert Betz

Betz's law indicates the maximum power that can be extracted from the wind, independent of the design of a wind turbine in open flow.

1919

where did it come from?

  • Conservation of mass and momentum

Where from?

What does it say?

What does it say?

  • No turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind.
  • The factor 16/27 (0.593) is known as Betz's coefficient.
  • Practical utility-scale wind turbines achieve at peak 75% to 80% of the Betz limit.

Consepts

  • Betz's law applies to all Newtonian fluids, including wind.

Concepts

Let me demonstrate

OH!

proof

The Betz Limit is the maximum possible energy that may be derived by means of an infinitely thin rotor from a fluid flowing at a certain speed.

Assumptions

Proof

  • The rotor does not possess a hub and is ideal, with an infinite number of blades which have no drag. Any resulting drag would only lower this idealized value.
  • The flow into and out of the rotor is axial. This is a control volume analysis, and to construct a solution the control volume must contain all flow going in and out, failure to account for that flow would violate the conservation equations.
  • The flow is non-compressible. Density remains constant, and there is no heat transfer.
  • Uniform thrust is exerted on the disc or rotor.

Calculating power

Approach 1

1

Calculating power

Approach 2

2

from 1 and 2

from 1 and 2

Conclusion

Conclusion

Learn more about creating dynamic, engaging presentations with Prezi