# Learning: Turbomachinery

## Advance ratio

*Image: An illustration describing the advance ratio, the ratio between the distance travelled in one revolution $F$, and the propeller's diameter. [1]*

The advance ratio is a non-dimensional number. It is the ratio between the forward distance travelled by the vehicle forward during one revolution of the propeller and the diameter of the propeller:

## Axial Flow Compressors - Mean Line Analysis

Preliminary design of axial compressors generally consist of a mean-line analysis, radial variations of airflow are ignored. The analysis is conducted at the mean blade radius location.

*Figure 1: Mean line of flow across the compressor stage.*

The ideal flow of fluid through a compressor stage can be illustrated by velocity triangle diagrams as shown in Figure 2. The fluid flow is assumed to travel along a path that follows the blade curvatures.