In the velocity diagrams for Francis turbine, which of the following velocity directions is along the blade curvature?

Related MCQs

• Volume flow rate of water in a Francis turbine runner is 25 m3/s. The flow velocity, whirl velocity and blade velocity are 11 m/s, 10 m/s and 5 m/s respectively, all values given at runner inlet. Find the power developed by the turbine.
• Power developed by Francis turbine are calculated for a certain set of conditions. Now, the inlet whirl velocity is doubled, the blade velocity at inlet is doubled and the flow velocity is quartered. The power developed:
• The available head of a Francis Turbine is 120 m. The blade velocity is given 35 m/s. Find the speed ratio of the turbine.
• A student performs an experiment with a Francis turbine. He accidently set the RPM of Francis turbine to 1400 rpm instead of 700 rpm. He reported the power to be 1 MW. His teacher asks him to perform the same experiment using the correct RPM. The student performs the same experiment again, but this time the erroneously doubled the flow velocity. What does the student report the power to be?
• The relative velocity of water at the inlet of the Kaplan turbine is 7 m/s. β1 = 75o. The whirl velocity of the water at inlet is 10 m/s. Find the blade velocity of the turbine?
• The whirl velocity at inlet of Francis turbine is given to be 20 m/s. The blade velocity is given as 35 m/s. What is the hydraulic efficiency for a head of 100 m?
• The power available at the shaft of a Francis turbine is 1 MW. The volume flow rate of water in 25 m3/s, whirl velocity at inlet is 10 m/s and blade velocity is 5 m/s. Find the mechanical efficiency (in %)?
• In the figure shown below, which of the following type of runners has the blade curvature as shown in the above figure (The arrow denotes direction of blade motion)?
• A Kaplan turbine requires a speed ratio of 2. The available head of the turbine is 5 m. What should be the blade velocity of the turbine such that a speed ratio of 2 is maintained (take g = 10 m/s2)?
• The desired hydraulic efficiency of a turbine is 80% at a whirl velocity of 20 m/s and a head of 100 m. What should be the blade velocity of the turbine at inlet in m/s?