friction-head

Century Dictionary and Cyclopedia

1. n. In hydraulics, the head lost in friction by an outflowing liquid. The friction-head is usually computed by the formula 4μ L/D. v/2g, where D is the diameter of the efflux pipe, L its length, v the velocity of the outflowing liquid, μ the coefficient of skin-friction, and g the acceleration due to gravity. See head, 7.