What is defined as a condition caused by an imbalance between inlet airflow velocity and engine rpm?

The condition referred to as an imbalance between inlet airflow velocity and engine RPM is known as compressor stall. This phenomenon happens when the compressor blades are unable to maintain the desired airflow through the engine due to excessive RPM or insufficient air velocity, leading to a disruption in the smooth airflow necessary for proper engine operation. When a stall occurs, the airflow can separate from the blades, creating a situation where the engine's efficiency diminishes, and it may even lead to a temporary loss of thrust.

In gas turbine operations, maintaining a balance between airflow and engine speed is crucial for optimal performance, and any deviation can result in instability, making the understanding of compressor stall essential in engine operation and design.