Modal Analysis of Conventional Gas Turbine Blade Materials (Udimet 500 and IN738) For Industrial Applications

Abstract

Finite element method (FEM) was utilized to determine the natural frequency of two turbine blade materials applicable to Trans-amadi power plant in Port Harcourt, Nigeria. Comparing the two gas turbine blade materials, the fundamental frequency under the same load condition was 751Hz for IN 738 and 896Hz for U500 turbine blade material. This implies that the natural frequencies obtained for both materials were much higher than the operational frequency of 85Hz for resonance to occur. Therefore, resonance would be delayed across the blade materials in service condition, indicating that gas turbine blades designed with both materials would be dynamically stable under operational frequency approaching 745Hz. It was observed that U500 gas turbine blade material which had a higher fundamental frequency has a better mechanical properties that can undergo a longer service condition in extreme working phase before failure compared to IN 738 material. This justification was deduced from the difference between the operational frequency and the fundamental frequency; as the closer the value obtained for fundamental frequency to the operational frequency, the higher the possibility of failure and vice versa. To avoid unforeseen failure and downtime in service operation, vibration test should be conducted on routine schedule in order to meet the expected performance of the gas turbine blade.

Keywords

• Gas turbine,Turbine blade,Failure,Resonance,Natural frequency,Vibration.

References

1. [1]Srinivasan, A. V., “Flutter and Resonant Vibration Characteristics of Engine Blades”, International Gas Turbine and Aero engine Congress and Exhibition, Orlando, Florida, June 2-5, ASME Technical Paper No: 97-GT-533, (1997): 1-36.
2. [2] Sulaiman, K. S., Rameshkumar, G. R., “Vibration Diagnosis Approach for Industrial Gas Turbine and Failure Analysis”, British Journal of Applied Science & Technology, 14(2) (2016): 1-9.
3. [3] Barhm M., “Failure analysis of gas turbine blade using finite element analysis”, International Journal of Mechanical Engineering and Technology, 7(3) (2017): 299-305.
4. [4] Ziegler, D., Puccinelli, M., Bergallo, B., Picasso, A., “Investigation of turbine blade failure in a thermal power plant", Case Studies in Engineering Failure Analysis, 1(3) (2013): 192-199.
5. [5] Ikpe, A. E., Owunna, I., Ebunilo, P. O., Ikpe, E., “Material Selection for High Pressure (HP) Compressor Blade of an Aircraft Engine”, International Journal of Advanced Materials Research, 2(4) (2016a): 59-65.
6. [6] Ikpe, A. E., Owunna, I., Ebunilo, P. O., Ikpe, E., “Material Selection for High Pressure (HP) Turbine Blade of Conventional Turbojet Engines”, American Journal of Mechanical and Industrial Engineering 1(1) (2016b): 1-9.
7. [7] Kalapala, P., Anjaneya, B. P., Anandarao, M., “Material Optimization and Dynamic Approach for performance criteria in application to Gas Turbine Blade to overcome resonance”, International Journal of Scientific & Engineering Research, 8(6) (2017): 189-196.
8. [8] Ivan B., Marco, A., Mathias, L., “Physically and Geometrically Non-linear Vibrations of Thin Rectangular Plates”, International Journal of Non-Linear Mechanics 58 (2014): 30-40.

9. [9] Bhupendra, E. G., Sachin V. B., Kapil B. S., “Vibration Analysis of Gas Turbine Blade Profile Using Fem Technique and Tool”, International Journal of Research in Advent Technology, 2(1) (2014): 182-189.
10. [10] Owunna, I., Ikpe, A. E., Satope, P., Ikpe, E., “Experimental Modal Analysis of a Flat Plate Subjected To Vibration”, American Journal of Engineering Research (AJER), 5(6) (2016): 30-37.
11. [11] Srinivasan, A. V., “Flutter and Resonant Vibration Characteristics of Engine Blades”, Journal of Engineering for Gas Turbines and Power, 119(4) (1997): 742-775.
12. [12] Adawi, S. K., Rameshkumar, G. R., (2016) “Vibration Diagnosis Approach for Industrial Gas Turbine and Failure Analysis”, British Journal of Applied Science and Technology, 14(2) (2016): 1-9.
13. [13] Lee C., “Recent Blade mounting Techniques”, Journal of Engineering for Gas Turbines and Power, 89(3) (2015): 437-444.
14. [14] Sushila, R., Atul, K. A., Vikas, R. (2017) “Failure Analysis of a First Stage IN738 Gas Turbine Blade Tip Cracking in a Thermal Power Plant”, Case Studies in Engineering Failure Analysis, 8 (2017): 1-10.
15. [15] Ikpe, A. E., Owunna, I., Satope, P., “Finite element analysis of aircraft tire behaviour under overloaded aircraft landing phase”, Aeronautics and Aerospace Open Access Journal, 2(1) (2018): 34-39.
16. [16] Ravi, R. K., Pandey, K. M., “Static Structural and Modal Analysis of Gas Turbine Blade”, IOP Conference Series: Materials Science and Engineering 225(012102) (2017): 1-9.