design and structural, thermal analysis of gas turbine rotor blade …ijpres.com/pdf30/8.pdf ·...

INTERNATIONAL JOURNAL OF PROFESSIONAL ENGINEERING STUDIES Volume VIII /Issue 2 / JAN 2017

IJPRES

DESIGN AND STRUCTURAL, THERMAL ANALYSIS OF GAS TURBINE ROTOR

BLADE 1 NAKKA NAGA VENKATA KRISHNAM RAJU, 2 A.M.VINOTH KUMAR, 3 V.CHANDRASHEKAR GOUD

1 Pg Scholar, Department of MECH, Aurora's Scientific Technological And Research Academy,

Bandlaguda, Keshavgiri Post, Chandrayanagutta, Near Pallecheruvu, Hyderabad, Telangana 500005 2 Assistant Professor, Department of MECH, Aurora's Scientific Technological And Research Academy,

Bandlaguda, Keshavgiri Post, Chandrayanagutta, Near Pallecheruvu, Hyderabad, Telangana 500005 3 Associate Professor, Department of MECH, Aurora's Scientific Technological And Research Academy,

Bandlaguda, Keshavgiri Post, Chandrayanagutta, Near Pallecheruvu, Hyderabad, Telangana 500005

Abstract

Cooling of gas turbine blades is a major

consideration because they are subjected to high

temperature working conditions. Several methods

have been suggested for the cooling of blades and

one such technique is to have radial holes to pass

high velocity cooling air along the blade span. The

forced convection heat transfer from the blade to the

cooling air will reduce the temperature of the blade to

allowable limits. modeling of gas turbine blade is

done in solid works 2016 design software. Finite

element analysis is used in the present work to

examine steady state thermal performance for

aluminum alloy, nickel alloy and titanium alloy. Four

different models consisting of solid blade and blades

with varying number of holes (7,8,9 holes) were

analyzed in this project to find out the optimum

number of cooling hole. It is observed that as the no.

of holes increases the temperature distribution

increase. The steady state thermal analysis is carried

out in ansys workbench software. It is observed that

blade with 9 holes has showing more heat flux than

the remaining blades. Finally the blade with 9 holes

has giving optimum performance for prescribed

loading conditions with average temperature of

1200degrees and convection 30degrees

Introduction to gas turbine:

Gas turbines are used for power generation. Today,

gas turbines are one of the most widely-used power

generating technologies. Gas turbines are a type of

internal combustion (IC) engine in which burning of

an air-fuel mixture produces hot gases that spin a

turbine to produce power. It is the production of hot

gas during fuel combustion, not the fuel itself that the

gives gas turbines the name. Gas turbines can utilize

a variety of fuels, including natural gas, fuel oils, and

synthetic fuels. Combustion occurs continuously in

gas turbines, as opposed to reciprocating IC engines,

in which combustion occurs intermittently.

2. Literature Survey

V. Veeraragavan had mainly done the research on the

aircraft turbine blades; his main focus was on 10 C4/

60 C50 turbine blades models. He had used the

conventional alloys such as titanium, zirconium,

molybdenum, and super alloys were chosen for the

analysis. He had analyzed the effect of the

temperature on the different material for the certain

interval of times. And conclude the molybdenum

alloys had better temperature resistance capability.

How does a gas turbine works:

Gas turbines are comprised of three primary sections

mounted on the same shaft: the compressor, the

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combustion chamber (or combustor) and the turbine.

The compressor can be either axial flow or

centrifugal flow. Axial flow compressors are more

common in power generation because they have

higher flow rates and efficiencies.

Gas Turbine Working Principle

Gas turbine engines derive their power from burning

fuel in a combustion chamber and using the fast

flowing combustion gases to drive a turbine in much

the same way as the high pressure steam drives a

steam turbine.

One major difference however is that the gas turbine

has a second turbine acting as an air compressor

mounted on the same shaft. The air turbine

(compressor) draws in air, compresses it and feeds it

at high pressure into the combustion chamber

increasing the intensity of the burning flame.

Fuel For Gas Turbine Power Plants

Gas turbine fuel systems are similar for all Turbines.

For the most common fuels, which are natural gas,

LNG (liquid natural gas), and light diesel, the fuel

system consists

A fuel delivery system,Fuel nozzles,Fuel additives

(to deal with vanadium), Fuel washing (to deal with

sodium and potassium Salts) and Modifications to the

fuel delivery system.

Applications Of Gas Turbine

The following are the applications of gas turbine

Land Applications: Central power stations,

Industrial and Industrial.

Space Applications: Turbo jet and Turbo prop.

Marine application

Introduction To Gas Turbine Rotor Blade:

Turbine Blade The rotor blades of the turbo machine

are very critical components and reliable operation of

the turbo machine as a whole depends on their

repayable operation. The major cause of break down

in turbo machine is the failure of rotor blade. The

failure of the rotor blade may lead to catastrophic

consequences both physically and economically.

Fig: gas turbine rotor blade

Manufacturing methodologies for turbine blade:

Rolling:

Sections are rolled to the finished size and used in

conjunction with packing pieces. Blades manufacture

by this method does not fail under combined bending

and centrifugal force.

Machining:

Blades are also machined from rectangular bars. This

method has more or less has the same advantage as

that of first. Impulse blade is manufactured by this

technique.

Forging:

Blade and vane sections having airfoil sections are

manufactured by specialist techniques.

Materials used for the turbine blades:

Turbine blades and vanes Cast super alloys

Recognition of the material creep strength as an

important consideration for the gas turbine volume

fraction andengines, understanding generated

between age hardening, creep and the steadily

increasing operating-temperature requirements for

the aircraft engines resulted in development of

wrought alloys with increasing levels of aluminum

plus titanium.

Component forgeability problems led to this direction

of development not going beyond a certain extent.

The composition of the wrought alloys became

restricted by the hot workability requirements. This

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situation led to the development of cast nickel-base

alloys. Casting compositions can be tailored for good

high temperature strength as there was no forgeability

requirement. Further the cast components are

intrinsically stronger than forgings at high

temperatures, due to the coarse grain size of castings.

Das recently reviewed the advances made in nickel-

based cast super alloys.

Methods Of Cooling

Convection Cooling:

It works by passing cooling air through passages

internal to the blade. Heat is transferred by

conduction through the blade, and then by convection

into the air flowing inside of the blade.

Fig: convection cooling

Impingement Cooling

A variation of convection cooling, impingement

cooling, works by hitting the inner surface of the

blade with high velocity air. This allows more heat to

be transferred by convection than regular convection

cooling does.

Fig: Impingement Cooling

Environment and failure modes:

Turbine blades are subjected to very strenuous

environments inside a gas turbine. They face high

temperatures, high stresses, and a potential

environment of high vibration.

The high temperatures can also make the blades

susceptible to corrosion failures. Finally, vibrations

from the engine and the turbine itself (see blade pass

frequency) can cause fatigue failures.

Solid Works

Solid Works is mechanical design automation

software that takes advantage of the familiar

Microsoft Windows graphical user interface. It is an

easy-to-learn tool which makes it possible for

mechanical designers to quickly sketch ideas,

experiment with features and dimensions, and

produce models and detailed drawings.

Modeling of gas turbine rotor blade

Gas turbine rotor blade (7 holes)



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Four views of gas turbine rotor blade

Basic Concepts of Analysis:

The software uses the Finite Element Method (FEM).

FEM is a numerical technique for analyzing

engineering designs. FEM is accepted as the standard

analysis method due to its generality and suitability

for computer implementation. FEM divides the

model into many small pieces of simple shapes called

elements effectively replacing a complex problem by

many simple problems that need to be solved

simultaneously.

Static Analysis:

When loads are applied to a body, the body deforms

and the effect of loads is transmitted throughout the

body. The external loads induce internal forces and

reactions to render the body into a state of

equilibrium. Linear Static analysis calculates

displacements, strains, stresses, and reaction forces

under the effect of applied loads.

Thermal Stress Analysis:

Changes in temperature can induce substantial

deformations, strains, and stresses. Thermal stress

analysis refers to static analysis that includes the

effect of temperature.

Perform thermal stress analysis using one of the

following options:

Using a uniform rise or drop in temperature for the

whole model.

Using a temperature profile resulting from a steady

state or transient thermal analysis.

Using a temperature profile from Flow Simulation

Material properties:

Meshing:

Fixed support

Load condition

Pressure 1 Mpa

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Material: Titanium alloy

Stress

Total deformation

Elastic stain

Material: inconel (nickel 625 alloy)

Stress

Total deformation

Elastic stain

Material: silicon carbide

Stress

Total deformation

Elastic stain

Structural Analysis On 8 Holes Blade

For Material: Titanium Alloy

Max stress

Total deformation

Max strain

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For Material: inconel

Max stress

Total deformation

Max strain

For Material: SiC

Max stress

Total deformation

Max strain

Structural Analysis On 9 Holes Blade

For Material: Titanium Alloy

Max stress

Total deformation

Max strain

For Material: inconel

Max stress

Total deformation

Max strain

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For Material: SiC

Max stress

Total deformation

Max strain

Thermal Analysis On Gas Turbine Rotaor Blade

Temperature load

Convection

Thermal Analysis On 7 Holes Blade

Material: Titanium Alloy

Temperature distribution

Heat flux

Material: inconel


Heat flux

Material: SiC


Heat flux

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Heat flux

Material: inconel


Heat flux

Material: SiC


Heat flux




Heat flux

Material: inconel


Heat flux

Material: SiC


Heat flux

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Structural Analysis Results

7 Holes

8holes

9 Holes

Steady State Thermal Analysis Results

For 7holes

For 8 holes

For 9 holes

Conclusion:

Modeling and analysis on gas turbine rotor blade is

done.

Modeling of turbine blade is done in solidworks

using various commands. Three models with 7holes,

8holes and 9holes are modeled.

Then the file is saved as igs to import in ansys

software.

The gas turbine blade model is imported to ansys

work bench software.

Structural analysis is done at 1mpa pressure with

three different materials such as titanium alloy,

inconel (nickel 625 alloy) and silicon carbide

Structural deformations such as stress, deformation

and strain are found and tabulated

From the results 9holes gas turbine blade with

inconel material obtaining low stress value compared

to other.

Next steady state thermal analysis is carried out on

turbine blade by applying different materials such as,

titanium alloy, inconel and sic at temperature 12000c

and 300c of convection

Temperature distribution and heat flux values are

noted and are tabulated.

From the analysis results we noticed that the

inconel material is showing maximum temperature

distribution.

Thus from the study we can conclude that inconel

material with 9 holes is more preferable compared to

remaining.

References

[1] Gowreesh, S., Sreenivasalu Reddy, N. and

Yogananda Murthy, NV. 2009. Convective Heat

Transfer Analysis of a Aero Gas Turbine Blade

Using Ansys, International Journal of Mechanics

and Solids. 4: 39-46.

[2] Facchini, B. and Stecco. S.S. 1999. Cooled

expansion in gas turbines: a comparison of analysis

methods, Energy Conversion and Management. 40:

1207-1224.

[3] Mohammad, H., Albeirutty., Abdullah, S.,

Alghamdi., Yousef, S. Najjar. 2004. Heat transfer

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analysis for a multistage gas turbine using different

blade-cooling schemes, Applied Thermal

Engineering. 24: 563-577.

[4] Mahfoud, K. and George, B. 1997. Computational

study of turbine blade cooling by slot-injection of a

gas, Applied Thermal Engineering. 17: 1141-1149.

1. NAKKA NAGA VENKATA KRISHNAM RAJU (pg scholar)

roll no: 14D91D1504

department: MachineDesign(MechanicalEngineering)

Aurora's Scientific Technological And Research

Academy, Bandlaguda, Keshavgiri Post,

Chandrayanagutta, Near Pallecheruvu, Hyderabad,

Telangana 500005

Email Id: [email protected]

2. A.M.VINOTH KUMAR

Assistant Professor





Telangana 500005

Email id:[email protected]

3. V. CHANDRASHEKAR GOUD

Associate Professor





Telangana 500005

Email Id:[email protected]

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