Benha University Shoubra Faculty of Engineering

Wind Cube Construction & Blade DesignConstruction & Blade Design

Simulation of The Project Simulation of The Project

Results & Future ModificationResults & Future Modification

Introduction Renewable energy:

is energy which comes from natural resources Renewable energy can be used again and again,

and will never run out

About 16% of global final energy consumption comes from renewable , with 10% coming from traditional biomass , and 3.4% from hydroelectricity , New renewable (small hydro, modern biomass, wind, solar, geothermal, and biofuel) accounted for another 3% and are growing very rapidly.

The types of renewable sources of energy :-

1- Hydropower Hydro-power is the capture of the energy of

moving water to generate electric power.

2- Tidal power Is a form of hydropower  that converts the energy of tides to generate electricity

3- Solar energy:- A solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using

the photoelectric effect. 

4- Biomass Biomass, as a renewable energy

source, is biological material from living, or recently living organisms. 

5- Geothermal energy Geothermal energy is thermal energy

generated and stored in the Earth.

6- Wind power Wind energy is energy collected from motion caused by heavy

winds. wind blows and turn the motion of the propeller into energy that

can be used in the electrical grid.

Advantages of wind power:-

clean fuel source.

don't produce atmospheric emissions

relies on the renewable power of the wind

lowest running priced renewable energy technologies

can be built on farms or rancheswhere most of the best wind sites are found

Why Wind Cube ?? Can be installed and operational quickly

Scalability (install one now and others later)

Easier to maintain than large wind turbines (all components easily accessible)

Unique design increases power generation

Smaller footprint

No land needed

Construction Main parts: up-frame Nozzle Generator chair:

The base: The base designed to bear the up-frame and the

generator chair and also have the availability of rotation (as wind direction is variable).

blade design Types Of Blades : 1.Horizontal-Axis Wind Turbines: are wind turbines whose axis of rotation is parallel to the ground.

2.Vertical-Axis Wind Turbines: . They have rotor blades that spin parallel to the ground

3. Savonius wind turbine 4. Giromill: 5.Darrieus wind turbine :

Differences between VAWT & HAWT : Installation: Coefficient of wind power use : Theoretically proved that the coefficient of wind power

use of ideal wind rotor (wheel) of any wind turbine (both HAWT and VAWT) is 0.593. It can be explained by the fact that rotors of both turbine types use the same effect of lifting force appearing when the wind is flowing around the profiled blade. The maximum coefficient of wind energy use on HAWT has reached

0.4 recently.  START OF OPERATING (SELF START)

DESIGN OF BLADE:

SWEPT AREA ON THE UNIT OF BLADE LENGTH : is the area of circle made by rotating blade ends. HIGH-SPEED DEGREE: HAWTs, are the high-speed turbines (up to 5-7 modules), with less

than 4 blades.  Vertical Axis the high-speed didn’t increase 2.5 – 2.8 modules Maintenance: For the same reason as above, VAWTs are easier to maintain since

most of them are installed near the ground. HAWTs should also be checked constantly so that it faces against

the wind, unlike VAWTs which require less maintenance. Automatic yaw-adjustment mechanisms have eliminated this need of constant maintenance on HAWTs though

Advantages of vertical wind turbines Easier to maintain have a higher airfoil pitch angle, giving improved aerodynamics

while decreasing drag at low and high pressures can be much easier to transport and install.  Does not need a free standing tower

Disadvantages of vertical wind turbines

produce energy at only 50% of the efficiency of HAWTs installed on a relatively flat piece of land Most VAWTs have low starting torque. 

Advantages of horizontal wind turbines stable.  Ability to wing warp, which gives the turbine blades the best angle

of attack. Ability to pitch the rotor blades in a storm, to minimize damage.  Tall tower allows access to stronger Can be cheaper

Disadvantages of horizontal wind turbines :

--> difficulty operating in near ground difficult to transport on the sea and on land Increase In Turbine Price

Computational fluid dynamics Computational fluid dynamics (CFD) is a branch

of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows

Background : 1- viscosity to yield the Euler equations 2- removing terms describing vorticity 3- linearized potential equations. 4- Steady state Flow 5- incompressible

Applications: AutoMotive

Turbo Machinery Aerospace Air Foils.

Advantages of CFD Relatively low cost. Speed. Ability to simulate real conditions

CFD PROCESS:

1- Create Mesh

2-boundry conditions 3-solve equations 4-iteratation

CFD for a nozzle with three blades

CFD for a nozzle with 5 blades

Advantages of 5-blade wind turbines over 3-blade wind turbines:

1) greatly improve annual energy 2) safe in high speed 3) lower wind turbine noise

Effect of tunnel with nozzle

Generator Choosing

Generator Cooling System : 1- Air Cooling 2- Water Cooling

Gearbox

Increase rpm ---- (n1/n2)=(z2/z1) - with out gear box we can reduce initial cost, eliminate the gearbox reduces maintenance

costs and enhances reliability as gearboxes are failure prone.

Results Measurement devicesWind speed & Direction devices :

Cup Anemometer Digital Anemometer

RPM Measurement A sensor is to sense shaft speed and sends speed data in the form of pulses

factors affect the quality of this data: 1. Number of pulses per revolution of

the shaft Higher PPR values result in better resolution.

2. Symmetry of pulses. give more accurate data.

RPM Measurement Types Of Sensors shaft encoders (rotary pulse generators)

- offer high resolution - (typically 1 to 5000 PPR) - symmetrical pulses.

Proximity Sensors

provide medium- or low-resolution sensing, depending on the number of pulses measured per revolution.

Photoelectric Sensors

usually provide low resolution, due to the low number of pulses measured per revolution.

Methods of Determining RPM Frequency measurement

Period measurement

Volt & Ampere measurement device:

Digital Multimeters Analog voltmeters

Results

Power = 0.5 x Swept Area x Air Density x (Velocity)3

Where Power is given in Watts (i.e. joules/second), the Swept area in square meters, the Air density in kilograms per cubic meter, and the Velocity in meters per second.

Betz' Law (The theoretical maximum power efficiency ) :

The rotors swept area = PI x (0.48/2)2 = 0.180955 m2

The air density = 1.23 kg/m3

Future modificationsto achieve the optimum design

1.Control system:

2.Safety system must happen on steps, at the beginning the pitch control will rotate the blades to minimize the lift force, then the control system should rotate the whole mechanism (cube) in a direction away from the wind direction, Finally the brake will operate to stop the rotor.

3.Electric system:-> Blocking diode

-> Battery-> Charge controller-> Dummy load-> Electric inverter

4. Nozzle on large scale

5. Adding scoop to the Tunnel

The scoop improves the power output of the wind turbine

by accelerating the airflow in the cylindrical section.

MOST EFFICIENT TECHNOLOGY

WindTamer Use the diffuser to separates the air, creating two vacuums, vacuums pull the air through, turning the rotors faster and generating more power more than double the energy of conventional turbines.

Advantages of the WindTamer :

-->Clean energy -->Silent and vibration free -->Safe for birds — and people -->MINIMAL MAINTENANCE -->EASY ACCESS