INTERNATIONAL JOURNAL OF PROFESSIONAL ENGINEERING STUDIES Volume V /Issue 3 /AUG 2015

IJPRES

DESIGN AND SIMULATION OF CENTRIFUGAL BLOWER USING COMPOSITE

MATERIALS

1 SAI RAGHU VEMURI, 2 P.V VISWANATH

1 PG Scholar, Department of MECH, Vidya Jyothi Institute of Technology, RangaReddy, Telangana, India. 2 Associate Professor, Department of MECH, Vidya Jyothi Institute of Technology, RangaReddy, Telangana, India.

Abstract— Centrifugal blowers are used in

naval applications and motors. The Contemporary blades

in Centrifugal Blower used in naval applications are

made up of Aluminum or Steel. It is proposed to design a

blower using Computer Aided Design (CAD) software

with various metal alloys and Non-Metallic composite

materials, analyze its strength and deformation using

simulation software. In order to evaluate the

effectiveness of Metal Alloys and Non-Metallic

composites.

The present work aim is to change the material and

performing the different analysis like Static, Dynamic,

Flow Simulation & Cost Analysis to find the best

material to decrease the weight and increase its efficiency

by using the software SOLID WORKS.

Key Words:

Centrifugal Blower, Computer Aided Design (CAD), Metal Alloys, Non-Metallic Composite Materials, SOLIDWORKS, Simulation Analysis.

I INTRODUCTION

A centrifugal blower is a mechanical device for moving air

or other gases. The terms "blower" and "squirrel cage fan"

(because it looks like a hamster wheel) are frequently used

as synonyms. Rotating impellers increase the speed of the

air blowing from other end.

They use the kinetic energy of the rotating blade or

impeller to increase the pressure and tends to slightly

decrease velocity of the air/gas stream which in turn moves

them against, dampers and other components which causes

the resistance. Centrifugal fans accelerate air radically,

changing the direction (typically by 90°) of the airflow.

They are quiet, sturdy, capable, and reliable of operating

over a wide range of critical conditions.

Centrifugal blowers are constant volume or displacement

devices, at a constant fan speed, centrifugal blowers will

pump a volume of air constantly irrespective with the

constant mass rate. This means that the air velocity in a

system is fixed even though mass flow rate through the fan

is not.

Centrifugal fans are well suited for industrial and

traditional purpose. It has a fan wheel composed of a

number of fan blades, or ribs, mounted around a hub. The

hub actuates on an electric driveshaft that passes through

the fan housing. The gas enters from the entrance of the

fan wheel, turns 90° and accelerates due to centrifugal

force as it flows over the curve of fan blades and exits the

fan housing.

Typical Centrifugal blower

INTERNATIONAL JOURNAL OF PROFESSIONAL ENGINEERING STUDIES Volume V /Issue 3 /AUG 2015

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Types of blowers Blowers can achieve much higher pressures than fans and

also produce negative pressures for industrial vacuum

systems. Main types of blowers ,which are described

below.

a) Centrifugal blower

b) Positive-Displacement Blower

Blower efficiency and performance:

Blower efficiency is the ratio between the power

transferred to the airstream and the power delivered by

the motor to the Blower. The power of the air flow is the

product of the pressure and the flow, corrected for unit

consistency.

Another term for efficiency that is often used with fans

is static efficiency, which uses static pressure instead of

total pressure in estimating the efficiency. When

evaluating fan performance, it is important to know

which efficiency term is being used.

The Blower efficiency depends on the type of fan and

impeller. As the flow rate increases, the efficiency

increases to certain height (“peak efficiency”) and then

decreases with further increasing flow rate. The peak

efficiency ranges for different types of centrifugal and

axial fans are given

Efficiency of Various Fans

Centrifugal Blower working principle

Centrifugal force is used as a main principle for the kinetic

energy produced by the impeller to the air/gas which is

used as a fluent. By this principle the gas enters in to the

impeller and thrown off by creating kinetic energy at the

exit. As a result, the pressure is measured in terms of

kinetic energy because of casting and duct which offers

system resistance. The gas is then guided to the exit via

outlet ducts. The gas pressure in the middle region of the

impellers decreases after it is thrown off. The cycle repeats

when the gas from the impeller eye rushes and therefore

the same volume of gas can be continuously transferred.

Velocity triangle: A diagram called a velocity triangle helps us in

determining the flow geometry at the entry and exit of a

blade. A minimum number of data are required to draw a

velocity triangle at a point on blade. Some component of

velocity varies at different point on the blade due to

changes in the direction of flow. Hence an infinite number

of velocity triangles are possible for a given blade. In order

to describe the flow using only two velocity triangles we

define mean values of velocity and their direction.

Velocity triangle of any turbo machine has three

components as shown.

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Velocity triangle for forward facing blade

These velocities are related by the triangle law of vector

addition: V= U+Vr

Where U= Blade velocity

Vr= Relative Velocity

V= Absolute velocity

Scope and objective of present work:

The Contemporary blades in Centrifugal Blower used in

naval applications are made up of Aluminum or Steel. The

objective of present work is to design a Impeller of a

Centrifugal blower with four materials, which are:

(a) Aluminum Alloy 1060

(b) Graphite

(c) Titanium

(d) E-glass/Epoxy

To analyze which material made impeller gives

better results in terms weight, Output pressure, Out-put

velocity, Breaking point, efficiency and cost-friendly.

These results can be obtained by performing the following

analysis on each material type.

(a) Static Analysis.

(b) Dynamic Analysis.

(c) Computational fluid dynamic (CFD)

Analysis.

(d) Cost analysis.

(e) Weight Analysis.

The modeling of the impeller and the above

mentioned analyses will be done by Solidworks software.

In addition to that a method to fabricate the Impeller with

E-glass/Epoxy is studied for realization of product.

LITERATURE REVIEW

(Dr). M.L Kulkarni has developed strategy and design procedure for blower which is expected to bring down the lead time during designing through the Reverse Engineering approach. The different dimensions & geometry of parts of the existing blower were found out by obtaining the Cartesian coordinates of various identified points. Thereafter the required profile and models were developed using this data with the help of CATIA V5 modeler. The Suction condition and other related data’s such as “inlet & outlet diameter”, “inlet & outlet vane angles” & “vane width” at the inlet and outlet were used to calculate specific data’s such as “Absolute velocity of the jet”, “velocity at the inlet and outlet”, “whirl velocity at outlet” and “exit angle of jet at the vane”. The project also covers areas of Geometric Analysis, Fluid Dynamics and Concept of Curve Generation

THEORITICAL CALCULATION:

Attempts are made to address this issue through considering the input values as below. Sl. No. Parameters Values

1 θ 40o 2 ф 50o 3 N 1300 rpm 4 b1 53.4 mm 5 b2 58.4 mm 6 r1 16.25 mm 7 r2 295 mm 8 R 381 mm 9 Blade curve Parabolic

ଵݑ = ଵݎ × ߱

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ଶݑ = ଶݎ × ߱

tan θ = v1/u1, v1 = vf1

Q = 2πr1b1v1

Vf2 = Q/2πr2b2

By using the above mentioned equations and input values, the following values were calculated:

Angular velocity ߱ = 136.13 rad/sec

Vane velocity at inlet u1 = 2.212 m/s

Vane velocity at outlet u2 = 29.4 m/s

Velocity of flow at inlet vf1 = v1 =292 m/s

Velocity of flow at outlet vf2 = 26.17 m/s

Discharge Q = 1.592 m/s

Whirl velocity at outlet Vw2= 12.47

ANALYSIS & DATA COLLECTION:

Material properties:

MODELLING AND SIMULATION:

Static Analysis on impeller of Al Alloy 1060:

Model with volumetric properties of AA1060

Applying Loads and fixtures

Applying Loads and Fixtures on impeller of AA1060

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Meshing:

Mesh information of AA1060

Meshed model of AA 1060

Static stress, Strain and total deformation values

Static stress result table of AA1060

Strain result of AA 1060

Total deformation table of AA1060

Dynamic Analysis

Dynamic Analysis on impeller of Al Alloy 1060:

Applying Loads and fixtures

Applying Loads and Fixtures on impeller of Al Alloy 1060 Dynamic Stress, Total deformation and Mass participation:

Dynamic stress result table of Al Alloy 1060

INTERNATIONAL JOURNAL OF PROFESSIONAL ENGINEERING STUDIES Volume V /Issue 3 /AUG 2015

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Total deformation table of Al Alloy 1060

Mass participation (normalized) table of Al Alloy 1060

Flow simulation

Applied Boundary Conditions

Inlet Velocity -14m\s

Angular velocity of impeller up to 13000 rpm

Pressure and velocity counters

Pressure Counters

Velocity Counters

Pressure and velocity distribution at blades

Pressure distribution at Blades

Velocity distribution at Blades

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Pressure and velocity flow trajectories:

Pressure flow trajectories

Velocity flow trajectories

As we observe the pressure counters, it is shown that the pressure is slightly decreased at the outlet due to the peek efficiency reached by the flow rate.

Cost analysis:

RESULTS, DISCUSSIONS AND CONCLUSIONS

Static Stress analysis results

Load applied on each material was 1500N

Minimum stress (N/M2) Vs. Material

Maximum stress (N/M2) Vs. Material

Deformation (Mm) Vs. Material

Dynamic analysis Results

Load applied on each material was 1500N

INTERNATIONAL JOURNAL OF PROFESSIONAL ENGINEERING STUDIES Volume V /Issue 3 /AUG 2015

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Minimum stress (N/M2) Vs. Material

Maximum stress (N/M2) Vs. Material

Deformation (Mm) Vs. Material

Flow Analysis Result

It is observed that the Velocity at out let is decreased

compared to inlet and Pressure increases at the outlet, due

to the peek effect.

Cost Analysis Result:

Material Cost

Manufacturing Costs

Total Costs

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Weight Analysis Result:

Weight Density Vs. Material

CONCLUSION

Modeling and simulation of centrifugal blower fan has done using Solid Works software.

After observing the static and dynamic analysis values we can conclude that e-epoxy has the better stress bearing capacity compared with the other materials except titanium deformation values by showing its better strength values to the applied loads.

During Flow simulation at impeller output velocity is decreased compared to inlet velocity, where as output pressure is increased compared to inlet pressure.

By using cost analysis methods, the material cost of each metal is noted shown in graphs and we can observe that cost of e-epoxy is slightly more than aluminum and this can be reduced in long run of manufacturing.

E-glass/Epoxy material is non metallic component so, the chattering noise will be low compared to other materials during the functioning process.

For manufacturing the centrifugal blower impeller we can proceed with Epoxy/E-glass material because it has high stress bearing capacity and reasonable manufacturing cost. FUTURE SCOPE:

CFD analysis of different types of impellers with change of RPM

The composition of e-epoxy can be changed with optimum composition of the resin and hardeners, So that the maximum stress acting on the material may reduce which proportionally decreases the deformation.

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