Engitek.com

All  Engineering and Technology Information in One Place.....

Home

About This Site

Sections  Directory

Search This Site

Privacy Policy

For Discussion of These Topics + Visit  the New Engitek Science and Technology Forum

 

Tired of looking for a job?, Cansado de buscar trabajo?

 

Semiconductors Devices

 

Electronics Technology Information Sites

 

Science and Tech Forum

 

Electronics Engineering Information by Categories

 

Engineering and Science Software

 

Free Science-Tek Magazines and Publications

 

Regulatory Offices and Agencies and Standards

 

Patents  Information

 

Prototypes Developing Houses, Devices and Tools

 

IC’s Foundries  and IC Development Services

 

Certification Labs

 

Operation Manuals

 

Physics Units Converter Calculators

Convert any type of unit into any other of any system or scale

 

Alternative Energies Tutorials:

Biofuels

Ocean Energy

Wind Energy

Solar Energy

Geothermal

 

Lean Manufacturing Tutorials:

The Seven Causes of Waste

The 5S

The 5 Why’s

The 4 M’s +1

Cause Effect / Fish Diagram  

The 4W’s +H+W

DMAIC

FMEA

Project Charter Example

Value Stream Mapping Introduction and Icons

Current or Present State Map

Future Sate Mapping

Cell Production

Kanban Production System

 

EarthquakesTutorials

 

Electronics and Electromechanical Distributors

 

Jobs Portal

Easily find your dream Job

 

Technology News

 

Science News

 

Business News

 

Electronics, RF and Communication Concepts

Rsistors and capacitors colors code

The Logarithm

The bel, decibel , the dbm and the dbmv

Electrical noise definition and Thermal noise

Signal to noise ratio

CONTENT

Lowest Prices for Solar Cells

Best Solar Energy Books

Lowest price Solar Panels

Wind Turbines and Parts

Best Wind Energy Books

Search this site

Para nuestros amigos de habla hispana, los invitamos a visitar el portal tecnológico en español:

www.industriaytecnologia.com

 

Wind Turbines, Number of Blades Selection

 

<< Continue from previous page

Number of Blades Selection

Previously the concepts solidity and tip speed ratio were revised in which it was learned that as the number of blades is increased, the tip RPM and tip speed of the rotor blade is reduced, but what other consideration must be taken into account for selecting any given number of blades?

If look around carefully, we will see that most medium and large turbines are made with rotors of tree blades, rarely having two or four or more, we have learned that the RPM increases with less blades turbines, right?, that is correct however they're also mechanical stability and structural integrity considerations in selecting not even number of blades.

As a brief example we will consider a two blades against a 3 blades rotor.

We know from the previous pages that the wind normally increases with height, so we will have two different forces hitting the rotor, one at the top blade and one at the bottom blade, now let see what happens in a two blade rotor:

 

Based on what we know, F2 will be > than F1 as consequence F2 will push the blade harder when in the upper vertical position causing a bigger bending as compared with the one at the lower position, as expected this will cause vibration on the whole rotor and in the turbine pole that can be highly destructive.

 

If we compare the tree blades rotor depicted below we can see that when one blade is at the top vertical position, the other two will be at lower point, but they still will be higher if compared with the lower blade in a two blades rotor visualized in doted lines. This means that the blade in the upper position will receive a wind force that is less different in power that the other two in the lower position, This situation causes less bending difference in the lower blades as compared with the ones in the upper position, as they will in a two blades rotor.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Wind turbine full schematic block diagram

 

Continue on next page >>

Bending

F2

F1

dif

Wind speed 2

= F2

Wind speed 1 = F1

Pole

Bending

And

Vibration

Two Blades Rotor

Three Blades Rotor

Another advantage of a three blades rotor is that any vibration due to the blades position is more smoothly distributed among them.

Lowest Prices for Solar Cells

Best Solar Energy Books

Lowest price Solar Panels

Wind Turbines and Parts

Best Wind Energy Books