DESIGN AND FABRICATION OF

BRIMMED DIFFUSER IN WIND

TURBINE BY

S. MARIMUTHU @ MATHAVAN (953211114027)

P. PON RAJESH KUMAR (953211114032)

R. SIVAGAMINATHAN (953211114049)

M. VIGNESH (953211114055)

GUIDED BYMr. N. SANKARESWARAN, M.E., (Ph.D)

AP/MECH

ANNA UNIVERSITY – TUTICORIN CAMPUSDEPARTMENT OF MECHANICAL ENGINEERING

III YEAR

ABSTRACT

This project work involves in the fabrication of BRIMMED DIFFUSER IN

WIND TURBINE.

To obtain a higher power output of the shrouded wind turbine, a shrouded

wind turbine equipped with a flanged diffuser has been developed, and

demonstrated power augmentation for a given turbine diameter and wind

speed

The flanged-diffuser shroud plays a role of a device for collecting and

accelerating the approaching wind.

PROBLEM DEFINITION

Efficiency of conventional wind turbine is low.

Conventional wind turbine produce more noise.

Separate yawing system is required.

Power production for a specific area is low.

Cut in velocity of conventional wind turbine is high.

In order to overcome the drawbacks in conventional wind turbine a brimmed

diffuser is used.

INTRODUCTION

Today, one of the most important problem facing by our nation is the

shortage in power. The production in power is less and the need is increasing

day by day.

So rather than implementing new ideas, working out for modifications in

the already existing ideas makes the investment in energy sources lesser.

In India, investments in energy sources are major on wind farms.

A special attachment to wind turbines, Wind Lens i.e. (BRIMMED

DIFFUSER) increases the efficiency of wind turbines.

Indirect form of Solar energy

In Wind Turbines

Kinetic energy of wind Mechanical energy Electrical energy

(rotor blades) (rotating shaft) (generator)

The movement of wind turbine blades explained by Bernoulli’s theorem

SOME BASICS OF WIND ENERGY

WIND-LENS CONCEPT

The Power developed (P) in the wind turbine is given by the

relation

P = Cp ρA (V)3

Where,

Cp = Power Coefficient

ρ = Density of air

A = Wind receiving area

V = Upstream velocity of wind

P ∝ V3

If one can accelerate the local wind speed by capturing and

concentrating the wind with some mechanism, there appears hope for

utilizing the wind power in a more efficient way.

Brim

WORKING

•The inlet shroud, a diffuser and a brim results in a low pressure area

behind the turbine which draws in more air creating even more power.

•As a result of the low pressure behind the diffuser , the air from the

surrounding which is in high pressure moves towards the low pressure

region.

•This in turns produces an vortex which increases the velocity of the wind

thereby increasing the efficiency of the turbine.

EFFECT OF BRIMMED DIFFUSER ON WIND TURBINE

Components of Wind Turbine with Brimmed Diffuser

Components Material

Blade PVC Pipe

Diffuser Aluminium Sheet

Truss Tower Steel

Nacelle Aluminium

Generator Commutated DC Motor

Hub Aluminium Plate

METHODOLOGY

Start ---------

Problem identification To increase the efficiency of the Wind

turbine.

Design of Shrouded wind turbine with

brimmed diffuser

Design proposed with brimmed diffuser.

Detailed design drawings Detailed drawings are drawn.

Purchase of materials Purchase of DC Motor and raw

materials.

Manufacturing process Manufacturing of truss tower, PVC

blades, DC motor shaft, DC motor coil,

Housing, Brimmed Diffuser and hub.

Assembly of Brimmed diffuser in wind

turbine as per proposed design

Assembly of truss tower, PVC blades,

Housing, Brimmed Diffuser, DC Motor

and hub.

Working model Wind turbine with brimmed diffuser

working

End -----------

DESIGN OF A BRIMMED DIFFUSER

Design Procedure for Brimmed Diffuser

Diameter of the rotor, D = 1010mm

Diameter of the hub, Dh

Dh / D = 0.2Dh= 0.2x1010Dh= 202mm

Length of the diffuser, LL / D = 0.225L = 0.225 x 1010L = 228mm

Height of the Brim, HH / D = 0.1H = 0.1 x 1010H = 101mm

Tip Clearance, Ht

Ht/ D = 1.5%Ht= 0.015 x 1010Ht= 15mm

Inclination angle of Diffuser, ɸtan ɸ = (Do - Di) / 2L

where, Do– Outer diameter of diffuserDi - Inner diameter of diffuser

tan ɸ = (1140 – 1040) / (2x228)tan ɸ = 0.219

ɸ = 12.370

Without Diffuser,

The velocity of wind V = 5m/s

Power, P = Cp x ρ x A x (V)3

= 0.5x1.522x(п/4) x(1.01)2x(5)3

P = 87.9 W

Velocity, V = п x D x N / 60

Speed, N = 5x60 / пx1.01

N = 94.55 rpm

Torque, T = P x 60 / 2 x п x N

= 87.9x60 / 2xпx94.55

Torque, T = 11040.01 N-mm

Torque, T = п x Ʈ x d3 / 16

Ʈ = 11040.01 x 16 / пx(12)3

Ʈ = 26.53 N/mm2

Shear stress Ʈ = 26.53 N/mm2

With Diffuser,

The velocity of wind V = 6m/s

Power, P = Cp x ρ x A x (V)3

= 0.5x1.522xп/4(1.01)2x(6)3

P = 131 W

Velocity, V = п x D x N / 60

Speed, N = 6x60 / пx1.01

N = 113.45 rpm

Torque, T = P x 60 / 2 x п x N

= 131x60 / 2xпx113.45

Torque, T = 11026.5 N-mm

Torque, T = п x Ʈ x d3 / 16

Ʈ = 11026.5x16 / пx(12)3

Ʈ = 32.498 N/mm2

From Design data Book, Pg. No: 1.12Yield stress for C-45 Steel = 380 N/mm2

Allowable stress = 380/2 =190 N/mm2

Design stress < Allowable stress

Design is safe

RESULT

Without Diffuser

Power = 87.9 W

With Diffuser

Power = 131 W

ADVANTAGES

• Brim-based yaw control

• Significant reduction in wind turbine noise

• Improved safety

• Improved cut-in velocity

• Increase in output power as compared to conventional wind turbines

PHOTOGRAPHY

CONCLUSIONThis prototype is simple, and the main advantages are increasing the

functionality of wind velocity and increasing over all power

generation without increasing the area of the rotor. Implementation of

this project increases the efficiency of wind turbine. It is used to

increase the power generation with brimmed diffuser. The application

areas are in wind turbine, ocean water turbines etc.

This “BRIMMED DIFFUSER IN WIND TURBINE” leads

to future device, which are helpful for mankind such as high efficiency

wind turbines.

REFERENCES

1. Kazuhiko Toshimitsu, Hironori Kikugawa, Kohei Sato, Takuya Sato. Experimental Investigation of Performance of the Wind Turbine with the Flanged-Diffuser Shroud in Sinusoidally Oscillating and Fluctuating Velocity Flows. . J. Wind Eng. Ind. Aerodyn.

2. Kothari, D.P., Umashankar, S.,2014. Wind Energy Systems And Applications. Narosa Publications.

3. Ohya, Y.; Karasudani, T.; Sakurai, A.; Abe, K.; Inoue, M. Development of a shrouded wind turbine with a flanged diffuser. J. Wind Eng. Ind. Aerodyn. 2008

4.5. Ohya, Y.; Karasudani, T. A Shrouded Wind Turbine Generating High

Output Power with Wind-lens Technology. J. Wind Eng. Ind. Aerodyn.

6. Faculty of Mechanical Engineering, PSG College of Engineering. (2011) ‘Design Data’, Kalaikathir Achchagam.