3D Flow Through Axial Turbines — Lesson 2

This lesson covers the intricate aspects of turbine aerodynamics, focusing on the three-dimensional aspects of flow through axial flow turbines. It delves into the similarities and differences between axial flow turbines and axial flow compressors. The lesson also explains the concept of three-dimensional flow and how it impacts the performance of turbines. It further discusses the theories developed to factor in the three-dimensionality of the flow. The lesson also touches upon the modern designs and analysis that have shown that some flows do acquire a certain amount of three-dimensionality. For instance, the lesson explains how the radial component of the flow becomes an important issue in three-dimensional flow. The lesson concludes by discussing the different design laws used in modern axial flow turbines.

Video Highlights

01:28 - Explanation of the three-dimensional flow in axial flow turbines.
06:01 - Explanation of the pseudo-three-dimensional design laws for turbine blades.
10:20 - Explanation of the radial equilibrium equation and its application in turbine design.
21:25 - Explanation of the free vortex law and its application in turbine design.
31:50 - Discussion on the constant nozzle exit angle model and its advantages in accommodating cooling.

Key Takeaways

- Turbine aerodynamics involves understanding the three-dimensional aspects of flow through axial flow turbines.
- The three-dimensional flow in turbines can be similar or different from that in axial flow compressors.
- The radial component of the flow becomes significant in three-dimensional flow.
- Modern designs and analysis have shown that some flows do acquire a certain amount of three-dimensionality.
- Different design laws are used in modern axial flow turbines, including the free vortex law, the constant nozzle exit angle model, and the arbitrary vortex case.