DESIGN OF GAS TURBINE BLADE WITH TEMPERATURE AND …

DESIGN OF GAS TURBINE BLADE

WITH TEMPERATURE AND STRESS ANALYSIS

Abstract - An optimized set of co-ordinates were taken for design of profile of blade followed by constant analysis of blade. oretical analysis is done to decipher stress and displacement in turbine blade. se stresses are developed by rmal and centrifugal loads. Present work gas turbine blade is analyzed using ANSYS18. Effect of temperature on turbine blade is calculated by induced stresses.

Best material for turbine blade is calculated by experimenting on three materials. geometric model of blade is generated in Solidworks. results are presented with ANSYS in paper.

Keywords- Blade profile, Gas turbine blade, High cycle fatigue, Static structural, Steady state thermal, SOLIDWORKS, ANSYS 18.1.

1 INTRODUCTION

Power generation in mechanical and aeronautical is done using gas turbine in some cases. Hot fast moving gases are made to hit blade to run turbine. Gas turbine is coupled with compressor. Turbine uses power generated to rotate compressor. Turbine extracts power by using energy of combusted gases.

Blades are extracting energy from gas produced by burner. Centrifugal forces are reason for high stresses on turbine blade. Failure is caused due to forces exerted on turbine blade. Vulnerability of blade is due to mixed effect of forces and temperature.

Energy from hot gases is extracted by turbine blade. This ability of turbine blades is responsible for performance of engine. Rotor blade failure is cause of breakdown in gas turbine. High losses are encountered due failure of rotor blades due to these conditions. Proper designing of gas turbine blade is important aspect for proper functioning of system. This is crucial matter for proper functioning and durable life of gas turbine engine.

In 2014, L.Umamaheswararao et al. [1] have explored stress distribution and temperature dissemination on gas turbine edge. Rotor edge of a gas turbine has been analyzed for auxiliary, thermal examination utilizing ANSYS. INCONEL 718 is utilized for edge of turbine blade. Thermal boundary conditions connected on rotor edge are taken from reference. Temperature distribution across blade is obtained. Most extreme stress up to which edge can withstand is known. Results are compared with N-155, Mellow Steel.

P.V.Krishnakanth et al. [2] have revealed theoretical analysis of turbine blade. Finally stating best suited material among three using analysis. From these results are stated and reported.

Nagpurwala Q.H Handbook [4] on Gas Turbine Design Manual is used. Assumptions and boundary conditions are taken from this data book.

2. PROBLEM STATEMENT

High centrifugal forces and high temperature cause high stress in gas turbine blades. High stresses in turbine blade cause change in shape of turbine blade. Change in shape of turbine blade is calculated by amount of stresses and deformation. Stresses need to be minimized. Life of gas turbine blade need to be increased.

2.1 Boundary Conditions

Firstly we shall assume nozzle loss coefficient λn = 0.05 as a reasonable guess.

Ashish Thakur1, Manish Mangal2 and Dr. Pikesh Bansal3Department of Mechanical Engineering, ABES Engineering College, Ghaziabad (U.P.), INDIA

Table 2.1 Boundary Conditions

Fig.2.1 Optimized Gas Turbine Blade with fir tree joint

Fig.2.2 Meshed View of Gas Turbine Blade

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Material: Ti 6Al 4V

4.2 Thermal Analysis of Blade using ANSYS 18.1

On basis of calculations done on software ANSYS 18.1 following results came under rmal analysis of blade which is done on basis of convection coefficient h and conduction coefficient k.

Material: Inconel 625

2.2 Material Properties

Material properties for following materials are taken for purpose of structural analysis of blade which was taken on ANSYS 18.1 for its structural and thermal analysis. structural and heat flux analysis is done on software ANSYS 18.1.

3. Design Calculations

Forces acting on system-

forces acting on system will be acting on three axis of design which are as follows:

Tangential force

Ft = mgas * (Ca2 + Ca3)

Axial force

Fa = mgas * (Cw2 + Cw3)

Centrifugal force

centrifugal force (Fc) produced due rotation of gas turbine blade is taken as 9690 N (Ti 6Al 4V), 11562 N (Inconel 625) and 11025 N (N 155).

For Ti 6Al 4V,

Axial force (Fa) = 9800/71 = 133.08 N per blade

Tangential force (Ft) = 10880/71 = 153.239 N per blade

Results and Discussion

4.1 Structural Analysis of Blade using ANSYS 18.1

Firstly meshing of design is done having number of nodes and finite elements

· Nodes 112029

· Elements 67728 respectively

Material: Inconel 625

Table 2.2 Material Properties

Table 3.1 Centrifugal forces

Fig.4.1.2

Normal Stress of Inconel 625

Fig.4.1.1

Total Deformation of Inconel 625

Fig.4.1.3 (a) Equivalent (Von- Mises) Stress of Inconel 625

Fig.4.1.3 (b) Equivalent (Von- Mises) Stress of Inconel 625

Fig.4.1.4 (b) Total Deformation of Ti 6Al 4V

Fig.4.1.5 Normal Stress of Ti 6Al 4V

Fig.4.1.6 Equivalent (Von- Mises) Stress of Ti 6Al 4V

Fig.4.2.1 Steady State thermal (Temperature Analysis) of Inconel 625

Design of Gas Turbine Blade with Temperature and Stress Analysis

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REFERENCES

[1] L. Umamaheswararao, Dr. K. Mallikarjunarao, “Design and analysis of a gas turbine blade by using FEM”, International Journal of Latest Trends in Engineering and Technology (IJLTET), Vol. 4, issue 4, November 2014

[2] P. V. Krishnakanth, G. Narasa Raju, R D V. Prasad, R. Saisrinu, “Structural & rmal Analysis of Gas Turbine Blade by Using F.E.M”, International Journal of Scientific Research Engineering & Technology (IJSRET), Volume 2, Issue2, pp 060-065, May 2013

[3] Ahmed Abdulhussein Jabbar, A. K. Rai, P. Ravinder Reedy & Mahmood Hasan Dakhil, “Design and analysis of gas turbine rotor blade using finite element method”, International Journal of Mechanical and Production Engineering Research and Development (IJMPERD), Vol. 4, Issue 1, 73-94, Feb 2014

[4] Q.H Nagpurwala “Axial Turbine design handbook”

[5] Turbine data Handbook on Gas Turbine by Siemens

CONCLUSION

In present work, two materials i.e. Titanium Ti 6Al 4V alloy and Inconel 625 have been taken for analysis. maximum Von- Mises stress of Inconel 625 is 2333.9 MPa and maximum Von- Mises stress of Titanium Ti 6Al 4V is 1931.3 MPa which is less comparatively. Hence, Titanium Ti 6Al 4V is better in terms of Von- Mises stress. Maximum total deformation in blade using Inconel 625 is 0.0013304 mm and using Titanium Ti 6Al 4V is 0.0014223 mm which is more than Inconel 625. Hence, Inconel 625 is better in terms of total deformation. Maximum normal stress in blade using Inconel 625 is 762.56 MPa and using Titanium Ti 6Al 4V is 612.9 MPa which is less than Inconel 625. Hence, Titanium Ti 6Al 4V is better in terms of normal stress. Heat flux calculated on design resulted to conclusion that material Titanium Ti 6Al 4V has a greater thermal bear ability resulting it a good preferable material with respect to our design in thermal and in structural analysis.

In future, detailed study of different materials and alloys that can be used in gas turbine blade should be done. Optimization of gas turbine blade to increase efficiency can be attempted. Or type of blade cooling techniques can be investigated to obtain maximum efficiency. Ceramics can be used to increase turbine inlet temperature for high efficiency. A new alternative can be taken in prospect of material of design is method of 3D Printing.

Fig.4.2.2 Steady State thermal (Directional Heat Flux) of Inconel 625

Fig.4.2.3 Steady State thermal (Temperature Analysis) of Ti 6Al 4V

Table 4.2.1 Thermal analysis results of the thermal distribution across the blade

Vision & Quest, Vol. 9, No. 2, Jan.-June 2019ISSN: 0975-8410

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