1. Innovative Design of Francis Turbine for Sediment Laden Water
International Conference on TIM, 2012, Nepal
Innovative Design of Francis Turbine for Sediment Laden Water
Krishna Prasad Shrestha1
Bhola Thapa1,
Ole Gunnar Dahlhaug2
Hari P. Neopane1
Biraj Singh Thapa1
1Dept. Mechanical Engineering, Kathmandu University, P.O. Box 6250, Dhulikhel, Nepal
2 Dept. Energy&Process Engineering, Norwegian University of Science and Technology,
NTNU, Trondheim, 7491, Norway

2. Outline Introduction Objectives Methodology Limitations
International Conference on TIM, 2012, Nepal
Outline
Introduction
Objectives
Methodology
Design of Francis runner
Core design process
Fluid Structure Interaction (FSI)
Limitations
Results and Discussion
Conclusions and Recommendation

3. International Conference on TIM, 2012, Nepal
Introduction
Hydro turbine running in the Himalayas and Andes Mountain of the South America are facing the same challenges of sediment erosion
Jhimruk power plant can be considered a severe one in Nepal
Renewable Nepal project, KU and Water power Laboratory, NTNU has developing Matlab based software called Khoj
Khoj facilitates to produce preliminary design data for Francis turbine with accountability of sediment erosion
CFD and FSI analysis has greater roll on improvement of hydraulic machine design and performance analysis

4. International Conference on TIM, 2012, Nepal
Runner blade
Francis turbine Runner blade after one year of operation at Jhimruk Power plant,
Nepal
Stay vane, Scroll casing, runner inspection at Telva Power Plant Norway
Runner assembly of Telva Power Plant Power plant

5. Objectives To analysis the impact of sand erosion on Francis turbine.
International Conference on TIM, 2012, Nepal
Objectives
To analysis the impact of sand erosion on Francis turbine.
To identify the possible solution for the minimizing effect of erosion on turbine.
To innovate optimization on Francis Turbine design.
To design and develop new Francis turbine.

6. Design of Francis runner
International Conference on TIM, 2012, Nepal
Design of Francis runner
Khoj software generated the data in terms of guide curves, blade curves, hub curve erosion factor, Velocity components, characteristic parameters, turbine dimensions and corresponding domains for the CFD analysis
On the basis of data prevailed by the software, turbine blade, hub and shroud data were imported to Pro/Engineer software
Hub
Shroud
Blade
3D Runner Assembly

7. Core design process SN Parameters Value Unit 1 Net design head(H)
International Conference on TIM, 2012, Nepal
Core design process SN
Parameters
Value
Unit 1
Net design head(H)
201.5 m 2
Net discharge per unit(Q)
2.35
m3/s 3
Runner efficiency() 96 %
Basic design parameter for JHC SN P1 P3 P4 P5 P6 P7 1
0.24
94.696
104.72 2
0.2 3
0.28 4
0.22
199.2 5
0.26
Optimized values for P1-vel R and head-H

8. Optimization Layout in ANSYS workbench
International Conference on TIM, 2012, Nepal
Core design process
Optimization Layout in ANSYS workbench

9. Pressure distribution Velocity distribution Pressure distribution
International Conference on TIM, 2012, Nepal
Core design process
Pressure distribution
Velocity distribution
Pressure distribution
R1 Blade
R2 blade

10. Pressure distribution Velocity distribution Pressure distribution
International Conference on TIM, 2012, Nepal
Core design process
Pressure distribution
Velocity distribution
Pressure distribution
R3 Blade
R4 Blade
R5 blade

11. Core design process Optimized trade-off charts 1
International Conference on TIM, 2012, Nepal
Core design process
Optimized trade-off charts 1
Efficiency, head, Shaft power and Velocity component Vel-R

12. Core design process Optimized trade-off charts 2
International Conference on TIM, 2012, Nepal
Core design process
Optimized trade-off charts 2
Efficiency, Flow, Shaft Power and Velocity component Vel-R

13. Core design process FEM analysis Pressure distribution on top cover
International Conference on TIM, 2012, Nepal
Core design process
FEM analysis
Pressure distribution on top cover
Pressure distribution on bottom cover

14. Core design process FEM analysis FSI Analysis Guide vane
International Conference on TIM, 2012, Nepal
Core design process
FEM analysis
FSI Analysis
Guide vane
Boundary condition location
Stress distribution on runner Assembly

15. Core design process (Vone Mess) Stress distribution on single blade
International Conference on TIM, 2012, Nepal
Core design process
(Vone Mess) Stress distribution on single blade
(Vone Mess ) Stress distribution on blade assembly
Deformation on runner

16. Limitations Optimization was performed only one set of blade profile.
International Conference on TIM, 2012, Nepal
Limitations
Optimization was performed only one set of blade profile.
FSI analysis was performed only on Francis turbine runner assembly.
During the FSI analysis, Unidirectional Coupling was chosen, considering there was no large deformation on runner.

17. Results and Discussion
International Conference on TIM, 2012, Nepal
Results and Discussion
Optimization was performed on CFD that signifies reducing simulation and cost of design
Trade-off chart determines the trade-off points which is used to show the relation between variables
Pressure distribution and velocity at trailing were observed by using CFD analysis
R2 Blade was selected for FSI analysis since it has found uniform pressure distribution as well as relatively lower velocity
FEM analysis was performed on guide vane, upper and lower cover
Unidirectional coupled FSI analysis prevailed that total deformation of runner assembly was m which is safe for structural steel

18. Conclusion and Recommendation
International Conference on TIM, 2012, Nepal
Conclusion and Recommendation
Erosion problem on Francis turbine due to sand laden water cannot be stopped completely by current technology but it can be minimized to the acceptable limit.
Use of FEM, CFD and FSI tool reduce the design process and simulation time meticulously.
New design processes found to be more sophisticated than the traditional way of design for the Francis turbine.
Simulated result predicted that the new design method can accommodate sand erosion problem in more sophisticated way.
It is recommended that simulation should be done in whole turbine unit and for better prediction two-way simulation is more reliable.

19. Recommendation
It is recommended that simulation should be done in whole turbine unit and for better prediction two-way simulation is more reliable.
Technological challenges and opportunities that recognize due to innovative design of Francis turbine should adopt by the turbine manufacturers.

20. Thank you very much for your time and attention!!! Any queries???
International Conference on TIM, 2012, Nepal
Thank you very much for your time and attention!!! Any queries???