FAA Powerplant Written Practice Test

In the initial construction of a 54 blade turbine rotor, how are blade numbers 1 and 2 positioned?

1. Adjacent to each other

2. 180 degrees apart from one another

3. Next to blade number 3

4. Aligned with the rotor's center

The correct answer is: 180 degrees apart from one another

In the construction of a turbine rotor, positioning blade numbers 1 and 2 180 degrees apart from one another ensures a balanced distribution of forces. This arrangement helps minimize vibrations and promotes even airflow across the entire rotor. The design aims to enhance the overall efficiency and stability of the turbine during operation. When blades are symmetrically arranged in this manner, it also provides structural integrity and optimizes performance. Maintaining balance is crucial in high-speed rotating machinery like turbine rotors due to the forces at play. Placing the first two blades directly across from each other serves to counteract unbalanced forces that could arise if they were positioned next to each other or in any other formation. The positioning relative to the rotor's center and other blades is designed to maximize aerodynamic efficiency and mechanical stability.