Design, Analysis and Material Optimization of Hybrid Cooling for Turbine Blades

Abstract

The main goal of the study is to optimize the material and processes utilized in turbine blades to improve their performance and the cooling efficiency. The most relevant area of interest is the hybrid cooling which initiates the thermal management problems of air internal turbine blade cooling by combining it with film cooling. The design has been done using Catia V5 and SolidWorks which includes parameter definitions that result in enhanced optimized blade geometry which further augmented by the increased air cooling. It is also paramount that the shape, size and placement of the cooling holes be controlled to improve thermal management while maintaining sufficient structural durability and strength. It is expected that with these refinements not only the heat dissipation ability of the blade improves but also the thermal loads on the surface will be reduced, which will enhance the lifespan and performance of the blade. Other analyses will seek to optimize materials to make them capable of enduring high temperatures while hybrid cooling resistance to thermal and mechanical stress. This study helps in the development of turbine blade cooling techniques to improve turbine operation performance and efficiency.

Introduction

1. Importance of Turbine Blades

• Turbine blades are critical in jet engines and power plants for converting high-temperature gas energy into mechanical work, which drives compressors or generates electricity.

• They must endure extreme temperatures and high rotational stresses while maintaining aerodynamic efficiency.

• Their shape and alignment are precisely engineered to maximize energy extraction and overall turbine performance.

2. Cooling Techniques

Due to operating temperatures often exceeding 1500°C, effective cooling is vital to prevent thermal stress, oxidation, and material degradation.

Cooling Methods:

• Internal Cooling: Air from the compressor flows through hollow blade passages (e.g., pin fins, serpentine channels, impingement holes) to absorb heat from blade walls.

• Film Cooling: Cool air is expelled through holes to form a protective film on the blade surface, shielding it from hot gases.

• Hybrid Cooling: Combines internal and film cooling for enhanced heat removal, ensuring reliability under extreme conditions.

• These techniques are essential for improving fuel efficiency, reducing emissions, and increasing turbine output.

3. Blade Design and Cooling Hole Geometry

Airfoil Selection:

• NACA 2412 airfoil is chosen for its aerodynamic balance, offering moderate lift with low drag—ideal for turbine applications.

• A leading edge radius of 44.5 mm ensures smooth airflow and effective cooling.

Design Variants:

• No-Hole Blade (Baseline): Structurally simple with maximum aerodynamic efficiency but lacks cooling capacity.

• Single-Hole Blade: Introduces circular holes for both internal and film cooling (2 mm diameter, 10 mm pitch, 15 rows).

• Double-Hole Blade: Advanced design with two closely spaced holes per location to improve coolant distribution and surface protection (2 mm holes, 9 rows).

• CAD software (CATIA V5 and SolidWorks) was used to model blade geometries accurately, ensuring minimal stress concentrations and aerodynamic integrity.

4. Material Selection & Thermal Analysis

Materials Evaluated:

• Inconel-718 & Inconel-738: Nickel-based superalloys with high-temperature strength and corrosion resistance.

• Ti-4Al-V6 & Ti-6242: Titanium alloys with high strength-to-weight ratios, suited for less thermally stressed areas.

Thermal Simulation (Ansys CHT Analysis):

• Simulations model conjugate heat transfer (solid-fluid thermal interaction) using:

  • Inlet temperature: 1600 K

  • Inlet velocity: 30 m/s

  • Hole air velocity: 5 m/s

  • k-epsilon turbulence model

• Accurate meshing and material property input allowed assessment of temperature distribution, heat flux, and thermal behavior.

5. Material Optimization

• Goal: Select materials based on thermal demands and strategically distribute them for efficiency and weight balance.

• Inconel alloys are placed in high-temperature zones due to their heat tolerance.

• Titanium alloys are used in cooler regions or where weight reduction is critical.

• Hybrid cooling analysis helps identify hot spots and guide material placement to enhance blade life, efficiency, and performance.

Conclusion

The research highlights about the combination of internal air cooling and film cooling known as hybrid cooling the study aimed to optimize hole geometries in order to enhance heat transfer and minimize thermal stresses. The use of advanced materials like Inconel-718, Inconel 738, Ti-4Al-V6 and Ti-6242 was under consideration based on their higher thermal and mechanical properties at elevated temperatures. Designing performed with the use of CATIA involved the creation of various hole shapes and configurations to find out their influence on cooling performance. The following analysis phase which is carried out in Ansys will perform thermal simulation to analyze the efficiency of every geometry and material. The end target is to determine a best-of-breed cooling design and material combination that will maximize heat transfer, minimize thermal fatigue and guarantee turbine blade longevity under severe conditions. The present work has the key potential for break throughs in advancing turbine technology towards improved efficiency and reliability for aerospace and power generation sectors.

References

[1] X. Wang, H. Xu, J. Wang, W. Song, and L. Wang, “High pressure turbine blade internal cooling in a realistic rib roughened two-pass channel,” Int. J. Heat Mass Transf., vol. 170, p. 121019, 2021, doi: 10.1016/j.ijheatmasstransfer.2021.121019. [2] A. A. J. A.-L., “Thermal Analysis of Cooling Effect on Gas Turbine Blade,” Int. J. Res. Eng. Technol., vol. 03, no. 03, pp.603610,2014,doi:10.15623/ijret.2014.0303112. [3] X. Meng, Y. Zhu, Y. Wang, and C. Liu, “Study on turbine blade overall cooling effectiveness under thermal radiation and non-uniform inlet temperature,” Case Stud. Therm. Eng., vol. 61, no. May, p. 105025, 2024, doi: 10.1016/j.csite.2024.105025. [4] S. Lee, W. Hwang, and K. Yee, “Robust design optimization of a turbine blade film cooling hole affected by roughness and blockage,” Int. J. Therm. Sci., vol. 133, no. February, pp. 216–229, 2018, doi: 10.1016/j.ijthermalsci.2018.07.012. [5] S. Dhivya and A. Karthikeyan, “Design and analysis of gas turbine blade with cooling,” EAI Endorsed Trans. Energy Web, vol. 18, no. 20, 2018, doi: 10.4108/eai.12-9- 2018.155742. [6] W. Wang et al., “Multidisciplinary Design Optimization of Cooling Turbine Blade: An Integrated Approach with R/ICSM,” Appl. Sci., vol. 14, no. 11, 2024, doi: 10.3390/app14114559. [7] T. M. Wolff, C. P. Bowen, and J. P. Bons, “The effect of particle size on deposition in an effusion cooling geometry,” AIAA Aerosp. Sci. Meet. 2018, no. February, 2018, doi: 10.2514/6.2018-0391. [8] L. Xu, Z. Sun, Q. Ruan, L. Xi, J. Gao, and Y. Li, “Development Trend of Cooling Technology for Turbine Blades at Super-High Temperature of above 2000 K,” Energies, vol. 16, no. 2, 2023, doi: 10.3390/en16020668. [9] S. Yan et al., “Advances in Aeroengine Cooling Hole Measurement: A Comprehensive Review,” Sensors, vol. 24, no. 7, 2024, doi: 10.3390/s24072152. [10] S. Dutta, I. Kaur, and P. Singh, “Review of Film Cooling in Gas Turbines with an Emphasis on Additive Manufacturing-Based Design Evolutions,” Energies, vol. 15, no. 19, 2022, doi: 10.3390/en15196968. [11] C. Zhang and M. Janeway, “Optimization of Turbine Blade Aerodynamic Designs Using CFD and Neural Network Models,” Int. J. Turbomachinery, Propuls. Power, vol. 7, no. 3, 2022, doi: 10.3390/ijtpp7030020. [12] H. Zhang, J. Gou, P. Yin, X. Su, and X. Yuan, “Film-cooling hole optimization and experimental validation considering the lateral pressure gradient,” Front. Mech. Eng., vol. 8, no. January, pp. 1–12, 2023, doi: 10.3389/fmech.2022.973293. [13] J. O’Hara and F. Fang, “Study on magnetohydrodynamic internal cooling mechanism within an aluminium oxide cutting tool,” Int. J. Adv. Manuf. Technol., vol. 132, no. 9– 10, pp. 4435–4460, 2024, doi: 10.1007/s00170-024-13542-7. [14] X. Qingzong, D. Qiang, W. Pei, and Z. Junqiang, “Computational study of film cooling and flowfields on a stepped vane endwall with a row of cylindrical hole and interrupted slot injections,” Int. J. Heat Mass Transf., vol. 134, pp. 796–806, 2019, doi: 10.1016/j.ijheatmasstransfer.2019.01.093. [15] S Krishnamoorthi, M. Prabhahar, S. A. M. Hassan, F.Imam, and F. Ahmad, “Design and Analysis of a Gas Turbine Blade by Using FEM,” AIP Conf. Proc., vol. 2523, pp. 479–486, 2023, doi: 10.1063/5.0113223.

Copyright

Copyright © 2025 Dr. Ajith V S, Amritha K, Ardra Krishna K, Arya P C, Athul Krishna S Nair. 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.