Question

The coefficient of fluctuation of speed is the _____________ of maximum fluctuation of speed and the mean speed.

(a) product

(b) ratio

(c) sum

(d) difference

This question was posed to me in an international level competition.

The query is from Fluctuation of Energy in chapter Turning Moment Diagrams and Flywheel of Machine Dynamics

Answer 1

The coefficient of fluctuation of speed is the ratio of maximum fluctuation of speed and the mean speed. The correct answer is (b) ratio.

This is a fundamental definition in machine dynamics related to flywheel design. The coefficient of fluctuation of speed (Cs) is expressed mathematically as:

Cs = (N_max - N_min) / N_mean

Where:

- N_max = maximum speed

- N_min = minimum speed  

- N_mean = mean speed

Key points:

- It measures the relative variation in speed

- It is expressed as a dimensionless ratio

- Lower values indicate better speed regulation

- It is critical for determining flywheel mass and design

- Related to the energy stored in the flywheel