Design and Finite Element Analysis (FEA) of Gas Turbine Rotor Disc

Abstract

A Turbine wheel (rotor) plays a significant role in gas turbine. The rotor on which the blades are mounted transmitting this motion holds a key point to better efficiency of gas turbine. Thus, more focus should be given to the design of the turbine rotor. Gas-turbine discs are normally operated at high temperatures. The hot gases contact the blades and the rim of the turbine rotor and thus maintain the rim at high temperature. The temperature gradient at rim and central portion of rotor causes the sources for thermal stresses. The disc is expected to perform well despite all the stringent operating conditions. The Advancement in gas turbine materials has been always a major concern—higher their capability to with stand elevated temperature service, produce lower stresses, light weight and more the engine efficiency. In this thesis, an attempt is made to determine the stresses like Thermal, Structural, Radial, and other stresses with different materials. The analytical analysis is carried out by using ANSYS to determine the intensity of stresses. Later an attempt is also made to determine the theoretical fatigue life and creep of the rotor disc.

Introduction

I. INTRODUCTION

Gas turbines have an important role in power generation and propulsion unit. Gas turbine technology is used in a variety of configurations for electric power generation.

Gas turbine is divided into three modules namely compressor, combustion & Turbine. In the gas turbine (GT), rotor consist of many components like rotor disc, blades, Intermediate shaft, front hollow shaft, rare hollow shaft, tie bolt, tie nut, support cone etc. A Turbine wheel/disc (rotor) plays a significant role in gas turbine.

The rotor on which the blades are mounted transmitting this motion holds a key point to better efficiency of gas turbine. Thus, more focus should be given to the design of the turbine rotor.

Gas-turbine discs are normally operated at high temperatures. The hot gases contact the blades and the rim of the turbine rotor and thus maintain the rim at high temperature.

The temperature gradient at rim and central portion of rotor causes the sources for thermal stresses. The disc is expected to perform well despite all the stringent operating conditions.

The Advancement in gas turbine materials has been always a major concern higher their capability to with stand elevated temperature service, produce lower stresses, light weight and more the engine efficiency.

In this thesis, the study has been carried out for compressor rotor disc subjected to higher temperature. Attempt are made to study the structural and thermal behaviours of the GT rotor disc.

A. Objectives

1. Evaluation of thermal behavior of the rotor disc rotating at high-speed operating condition and subjected to varying temperature.
2. Evaluation of structural behavior of the rotor disc when subjected to various load like blade pull, bolt pretension etc.
3. To perform the strength assessment.
4. To predict the fatigue life of the rotor disc
5. To perform the creep assessment of rotor disc.

V. FUTURE SCOPE

The future scope for FEA rotor disc thesis can encompass several areas of research and development. Here are a few potential directions:

1. Advanced material modeling.
2. Nonlinear analysis.
3. Fracture mechanics.
4. Multi-physics coupling.
5. Uncertainty quantification.
6. Optimization and design improvement.
7. Experimental validation.
8. Condition monitoring and predictive maintenance.
9. Computational efficiency and parallel computing.

These are just a few potential areas for future research in FEA rotor disc analysis. Depending on your specific interests and goals, you can further refine and explore these areas or identify new directions to contribute to the field.

Conclusion

In conclusion, the finite element analysis (FEA) conducted on the gas turbine rotor disc has provided valuable insights into its structural integrity and performance. The FEA results, in conjunction with analytical studies, have demonstrated that the rotor disc is deemed safe under the specified boundary conditions and environmental factors. This analysis has helped ensure that the rotor disc can withstand the anticipated mechanical loads and thermal stresses during normal operation. By incorporating comprehensive fatigue and fracture analyses into the assessment process, engineers can gain a deeper understanding of potential failure modes, identify areas of concern, and make informed design decisions to enhance the component\'s durability and longevity. These further analyses will provide a more comprehensive evaluation of the rotor disc\'s performance, ensuring its ability to withstand unexpected loading scenarios and maintain safe operation throughout its service life.

References

[1] Element of fracture mechanics book by Prashant Kumar [2] Mechanical Engineering Design by Richard G, Budynas (Shigley’s) [3] An introduction to finite element method McGraw-Hill, New York by J.N. Reddy [4] Strength of Material by R K Bansal [5] Fundamentals of Machine Component Design by Robet C, Juvinall [6] Research Article Transient Analysis and Design Improvement of a Gas Turbine Rotor Based on Thermal-Mechanical Method by Yang Liu, Qi Yuan, Guangyu Zhu and Pu Li. [7] Case Study-Thermal analysis of gas turbine disk integrated with rotating heat pipes published by ELSEVIER source: sciencedirect.com. [8] https://www.sciencedirect.com/science/article/abs/pii/S0142112310002689 For Temp Factor [9] https://www.quadco.engineering/en/know-how/material-fatigue-surface-roughness-factor.htm for Surface Roughness factor [10] https://chemengineerkey.com/4-internal-flow-around-rotors-and-stators/ [11] https://www.sciencedirect.com/science/article/abs/pii/S0142112301000445#:~:text=Under%20high%2Dcycle%20(or%20stress,strength%20coefficient%2C%20b%20is%20the [12] https://issuu.com/tjprc/docs/2-67-1584599800-60.ijmperdapr202060 [13] https://ia903102.us.archive.org/33/items/MechanicalEngineeringDesign9th/Mechanical%20Engineering%20Design%209th.pdf [14] https://gearkade.com/Gearkade%20content/Books/Fundamentals%20of%20Machine%20Component%20Design.pdf

Copyright

Copyright © 2023 Diwakar ., Siddharth . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.