Characteristics of Axial Flow Compressors — Lesson 1

This lesson covers the performance characteristics of single and multistage axial compressors in turbomachinery aerodynamics. It explains the importance of these characteristics for designers and engine operators, as they determine the operational limits of the engine. The lesson delves into the parameters that influence the performance of a single stage axial compressor, such as the loading coefficient, flow coefficient, and efficiency. It also discusses the impact of changing operating conditions on the compressor's performance. For instance, it explains how a change in mass flow rate or rotor speed can affect the inlet angle and subsequently the compressor's performance. The lesson further extends the discussion to multistage axial compressors, highlighting the variables that affect their performance, including mass flow rate, inlet stagnation pressure and temperature, rotational speed, and the design and diameter of the compressor. The lesson concludes by discussing the concept of compressor maps and the potential instabilities that can affect compressor performance, such as rotating stall and surge.

Video Highlights

03:19 - Analysis of how the performance of a single stage varies as the operating conditions change.
09:31 - Discussion on the parameters on which the performance of a single stage axial compressor depends .
19:41 - Discussion on the performance characteristics of a multistage axial compressor and the parameters it depends upon.
51:07 - Explanation of the concept of surge margin and its importance in engine design.

Key Takeaways

- Performance characteristics of axial compressors are crucial for designers and engine operators as they determine the operational limits of the engine.
- The performance of a single stage axial compressor depends on parameters such as the loading coefficient, flow coefficient, and efficiency.
- Changes in operating conditions, such as mass flow rate or rotor speed, can significantly affect the compressor's performance.
- The performance of a multistage axial compressor depends on several variables, including mass flow rate, inlet stagnation pressure and temperature, rotational speed, and the design and diameter of the compressor.
- Compressor maps are used to express compressor performance and form a significant part of the design process for gas turbine engines.
- Potential instabilities, such as rotating stall and surge, can drastically affect compressor performance.