Modelling and simulation for defect detection in hydroelectric penstock using infrared thermography

Ho Jong Kim, Rakish Shrestha, Samman Singh Pradhan, Prithvi Gurung, Prabesh Bhattarai, Nirjal Lamichhane, Cheol Sang Kim, Ranjit Shrestha

Article ID: 2494
Vol 6, Issue 2, 2023

VIEWS - 552 (Abstract) 154 (PDF)


Modelling and simulation have now become a standard method that serves to cut the economic costs of R&D of novel advanced systems. This paper introduces the study on modelling and simulation of infrared thermography process to detect the defects in the hydroelectric penstock. A 3-D penstock model was built in ANSYS version 19.2.0. Flat bottom holes of different sizes and depths were created on the inner surface of the model as an optimal scenario to represent the subsurface defect in the penstock. The FEM was applied to mimic the heat transfer in the proposed model. The model outer surface was excited at multiple excitation frequencies by a sinusoidal heat flux and the thermal response of the model was presented in the form of thermal images to show the temperature contrast due to the presence of defects. Harmonic approximation method was applied to calculate the phase angle and its relationship with respect to defect depth and defect size was also studied. The results confirmed that the FEM model has led to a better understanding of lock-in infrared thermography and can be used to detect the subsurface defects in the hydroelectric penstock.


penstock; subsurface defects; non-destructive testing and evaluation; infrared thermography; lock-in thermography; thermal image; phase angle

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1. Pradhan GL, Lacoul S, Bhat SS, Carpentier JM. Vision 2020: Hydropower—A vision for growth. Hydro Nepal Journal of Water Energy and Environment 2009; 4: 56–58. doi: 10.3126/hn.v4i0.1830

2. Singhal MK, Arun K. Optimum design of penstock for hydro projects. International Journal of Energy and Power Engineering 2015; 4(4): 216–226. doi: 10.11648/j.ijepe.20150404.14

3. Alam F, Alam Q, Reza S, et al. A review of hydropower projects in Nepal. Energy Procedia 2017; 110: 581–585. doi: 10.1016/j.egypro.2017.03.188

4. Government of Nepal, Ministry of Water Resources, Department of Electricity Development. Design Guidelines for Water Conveyance System of Hydropower Projects. Department of Electricity Development; 2006.

5. Aifaoui N, Affi Z, Abbes MS, et al. Design and modeling of mechanical systems—IV. In: Proceedings of the 8th Conference on Design and Modeling of Mechanical Systems, CMSM’2019; 18–20 March 2019; Hammamet, Tunisia.

6. Bergant A, Simpson AR, Tijsseling AS. Water hammer with column separation: A historical review. Journal of Fluids and Structures 2006; 22(2): 135–171. doi: 10.1016/j.jfluidstructs.2005.08.008

7. McStraw B. Inspection of steel penstocks and pressure conduits. In: Facilities Instructions, Standards, and Techniques. U.S. Department of the Interior; 2000.

8. Ma Z, Lu Y, Hu F, et al. The material comparison design of penstock pipe for a hydroelectric pumped storage station. Journal of Physics: Conference Series 2021; 2009(1): 012027. doi: 10.1088/1742-6596/2009/1/012027

9. Qu Z, Jiang P, Zhang W. Development and application of infrared thermography non-destructive testing techniques. Sensors 2020; 20(14): 3851. doi: 10.3390/s20143851

10. Yoo KH, Kim JH, Na MG, et al. On-power detection of wall-thinned defects using lock-in infrared thermography. Nuclear Engineering and Design 2014; 280: 542–549. doi: 10.1016/j.nucengdes.2014.10.008

11. Maldague XP. Theory and Practice of Infrared Technology for Nondestructive Testing. Wiley-Interscience; 2001.

12. Meola C, Carlomagno GM. Recent advances in the use of infrared thermography. Measurement Science and Technology 2004; 15(9): R27–R58. doi: 10.1088/0957-0233/15/9/r01

13. Czichos H. Handbook of Technical Diagnostics. Springer Berlin Heidelberg; 2013.

14. Vavilov V, Burleigh D. Infrared Thermography and Thermal Nondestructive Testing. Springer Cham; 2020.

15. Ranjit S, Kang K, Kim W. Investigation of lock-in infrared thermography for evaluation of subsurface defects size and depth. International Journal of Precision Engineering and Manufacturing 2015; 16(11): 2255–2264. doi: 10.1007/s12541-015-0290-z

16. Ranjit S, Choi M, Kim W. Quantification of defects depth in glass fiber reinforced plastic plate by infrared lock-in thermography. Journal of Mechanical Science and Technology 2016; 30(3): 1111–1118. doi: 10.1007/s12206-016-0215-5

17. Shrestha R, Park J, Kim W. Application of thermal wave imaging and phase shifting method for defect detection in Stainless steel. Infrared Physics & Technology 2016; 76: 676–683. doi: 10.1016/j.infrared.2016.04.033

18. Shrestha R, Kim W. Evaluation of coating thickness by thermal wave imaging: A comparative study of pulsed and lock-in infrared thermography—Part I: Simulation. Infrared Physics & Technology 2017; 83: 124–131. doi: 10.1016/j.infrared.2017.04.016

19. Chatterjee K, Tuli S, Pickering SG, Almond DP. A comparison of the pulsed, lock-in and frequency modulated thermography nondestructive evaluation techniques. NDT & E International 2011; 44(7): 655–667. doi: 10.1016/j.ndteint.2011.06.008

20. Wallbrink C, Wade SA, Jones R. The effect of size on the quantitative estimation of defect depth in steel structures using lock-in thermography. Journal of Applied Physics 2007; 101(10): 104907. doi: 10.1063/1.2732443

21. Shrestha R, Kim W. Non-destructive testing and evaluation of materials using active thermography and enhancement of signal to noise ratio through data fusion. Infrared Physics & Technology 2018; 94: 78–84. doi: 10.1016/j.infrared.2018.08.027

22. Shrestha R, Kim W. Evaluation of coating thickness by thermal wave imaging: A comparative study of pulsed and lock-in infrared thermography—Part II: Experimental investigation. Infrared Physics & Technology 2018; 92: 24–29. doi: 10.1016/j.infrared.2018.05.001

23. Shrestha R, Chung Y, Kim W. Wavelet transform applied to lock-in thermographic data for detection of inclusions in composite structures: Simulation and experimental studies. Infrared Physics & Technology 2019; 96: 98–112. doi: 10.1016/j.infrared.2018.11.008

24. Shrestha R, Choi M, Kim W. Thermographic inspection of water ingress in composite honeycomb sandwich structure: A quantitative comparison among lock-in thermography algorithms. Quantitative InfraRed Thermography Journal 2019; 18(2): 92–107. doi: 10.1080/17686733.2019.1697848



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