- Centrifugal pumps use impellers to impart velocity and pressure to fluids. Impellers can have single or multiple stages. - Affinity laws describe how flow rate, head, speed, and power relate as variables change. Centrifugal pump performance can be predicted using these scaling relationships. - Specific speed is used to classify pumps based on geometric similarity. Euler's and Bernoulli's equations relate velocities, pressures, and heads in centrifugal pumps. - Stepanoff's method uses empirical coefficients to design centrifugal pumps based on design parameters like flow rate, head, speed, and impeller dimensions. Blade thickness affects internal velocities.