What is the difference between geometric pitch and effective pitch in propellers referred to?

The distinction between geometric pitch and effective pitch in propellers is fundamentally related to the concept of slip. Geometric pitch refers to the theoretical distance a propeller would move forward in one complete revolution, based on its design and blade angle. However, in practice, the actual distance a propeller moves through the air is often less than this theoretical distance, due to various factors like fluid resistance and the propeller's interaction with the air. This difference between the theoretical distance (geometric pitch) and the actual distance traveled (effective pitch) is what is referred to as "slip."

Slip quantifies the efficiency loss encountered during operation, illustrating how real-world conditions can affect the performance of a propeller. Understanding slip helps engineers and pilots assess how well a propeller is performing relative to its design specifications and is crucial for optimizing the operation of aircraft with propeller systems. This concept is critical for enhancing the design and functionality of propellers in aviation engineering.