Which condition must be maintained for the optimal operation of an axial compressor?

For optimal operation of an axial compressor, it is essential to maintain balanced airflow and RPM. This balance ensures that the compressor operates within its designed performance range, maximizing efficiency and minimizing the risk of compressor stall or surge.

Axial compressors work by maintaining a stable flow of air through multiple stages of rotating and stationary blades. If the airflow is not balanced with the rotational speed (RPM), it can lead to performance issues such as vibrations, increased drag, and inefficient compression. Proper coordination between airflow and RPM also helps in maintaining specific pressure ratios across the compressor stages, which is crucial for overall engine performance.

In contrast, constant airflow alone does not take into account the interaction with RPM, which is vital for maintaining the aerodynamic characteristics of the compressor. Variable speed limits can be necessary in some applications, but without the balance with airflow, it does not guarantee optimal performance. Increased fuel flow is more relevant to the combustion process and does not directly influence the aerodynamic performance of the compressor itself. Thus, maintaining balanced airflow and RPM is crucial for the steady and efficient operation of an axial compressor.