Objectives
● To investigate the deviation in pressure pulsation
signals in Francis turbine due to shark bite in
runner blades numerically and experimentally
● To develop a correlation between signals affected
by broken blades.
Expected Outcomes/ Summary:
With the increasing demand for energy in the market, there is increased demand for more reliability and
efficiency. To compensate for this fluctuation in the energy market, hydropower plants are used as the base energy. As a result, Francis turbines, which are one of the most common turbines, must function in off-design settings resulting in increased maintenance cost and risk of failure for the power plants. When the turbines are run outside the operating range of ideal flow, static pressure loads deviate from design conditions, and pressure fluctuations increase leading to dynamic instability in the turbine and its parts. These unwanted pressure pulsations lead to stress and significant vibration that damage the turbine parts. Fatigue crack on blade is one such damage that is caused due to turbine operating in off design
conditions. The main goal of this study is to investigate the fatigue crack on the runner by analyzing the pressure pulsations in various locations in the turbine. A part of the blade is broken in the trailing edge near the shroud to imitate the shark bite which is the faulty case. This is kept identical for both the numerical and experimental study. Significant pressure fluctuation was visible in the areas
between affected runner blades and guide vanes and in the draft tube area. The numerical results will be validated using the experimental approach. The experimental study will be done at the Waterpower laboratory in NTNU.
Supervisors from host and Partner Universities
Prof. Hari Prasad Neopane (Department of Mechanical Engineering, KU)
Asst. Prof. Sailesh Chitrakar (Department of Mechanical Engineering, KU)
Prof. Ole Gunnar Dahlhaug (NTNU)
About myself
I’m a person who loves to be in nature breathing in the symphony of the wilderness. I love going out to hike or for a small walk and am usually collecting rocks, leaves and pinecones and decorating them. I love crafting DIY wonders and sketching. I find them as my sanctuary for expression and meditation.
I love reusing and recycling things as much as I can. I am a resourceful person and I love to repair and mend things before throwing them away. When I’m at my home, I’m usually assisting my dad to repair different items. I believe my problem-solving approach in life and my love for working with machines has sparked because of him. Professionally, I have delved into mechanical engineering where I
constantly get to challenge and leverage my creativity and knowledge. During my study and work, I got to work and learn from a lot of people who have helped me grow professionally as well as personally to make the person I’m today. Furthermore, I love hearing people’s stories and weaving connections with new souls. Right now, as an exchange student, I’m getting the opportunity to learn and experience a new culture that is helping me to build and broaden my perspective and experience. I am a person fueled by curiosity. I love exploring and creating art and being in nature.
Aasma Bhattarai
Masters by Research
bhattarai.aasma2@gmail.com
Batch 2021