Design of Turbine Blades in 3D — Lesson 4

This lesson covers the intricate process of axial flow turbine design. It delves into the various steps involved in creating a three-dimensional turbine blade, starting from the selection of design parameters to the final prototype making and rig testing. The lesson emphasizes the importance of using airfoil profiles, databanks, and simple theories in the design process. It also highlights the role of computational fluid dynamics (CFD) in refining the design. The lesson further explains the significance of the mean diameter in the design process and the need for a step-by-step approach. It also discusses the impact of losses on the actual work produced by the turbine.

Video Highlights

01:26 - Discussion on the process of building a three-dimensional turbine blade using simple theories and the importance of databanks in the design process.
12:46 - Explanation of the parameters to be selected from the preliminary cycle for the design of axial flow turbines.
19:59 - Explanation of the process of designing the blades of an axial flow turbine, including the selection of parameters, design initiation at the mean diameter, and the consideration of radial variation of parameters.
28:17 - Discussion on the importance of blade design and the selection of design parameters.
45:31 - Explanation of how to calculate the axial velocity, the rotor losses, and the stage efficiency in the design process.
51:05 - Discussion on the final steps in the design process, including the calculation of the area at the rotor exit, the determination of the hub to tip diameter ratio, and the calculation of the relative velocity.

Key Takeaways

- The design process of an axial flow turbine involves selecting design parameters, initiating design at the mean diameter, and considering radial variation of parameters.
- The design process is aided by databanks that provide initial data and help in the selection of profiles.
- The design needs to be submitted for rigorous computational fluid dynamics (CFD) analysis for refinement.
- The design process also involves creating a three-dimensional turbine blade and determining the number of stages in a multistage turbine.
- The final design of the turbine blade requires intense analysis and optimization between gas dynamics, thermal load, and stress calculations.