Assignment No

Assignment no.3 Fluid Machinery (ME – 306) 1. Explain how the suction height of a turbine above tail race level is limited by cavitation? 2. Define the specific speed of a turbine? Derive an expression for specific speed. What is the significance of specific speed? 3. By means of neat sketch explain the governing mechanism of Francis turbine. 4. What is a draft tube? Why is it used in a reaction turbine? 5. Explain the different efficiency ratings of a centrifugal pump. 6. Why pumps are generally less efficient than turbines? 7. How does a centrifugal pump impart pressure energy to the flowing fluid? 8. Explain when the hydraulic and manometric efficiencies of a pump become synonymous? 9. Show by sketches the differences between a volute pump and a diffusion pump. 10. What is the function of a diffuser in a centrifugal pump?