Venturi

Part of speech: noun

Pronunciation: /vɛnˈtjʊəɹi/

Definitions

1. A measurement tool that regulates fluid flow through a narrowed area to generate a differential pressure
2. A specialized device that alters the velocity and pressure of a fluid by constricting its path within a tube
3. A mechanical instrument that facilitates the measurement of fluid dynamics by creating a pressure difference through a constriction in its flow path

Etymology: Giovanni Battista Venturi was an Italian physicist, born in 1746, who studied how air and water move through channels of varying width. The device that bears his name exploits a counterintuitive effect: when a fluid passes through a narrowed section of a pipe, it speeds up, and its pressure drops. By measuring that drop, one can work out how fast the fluid is flowing, which is why the instrument became a standard tool for measuring flow. The word is therefore a pure eponym, formed from the surname of a single scientist and used as a noun for the apparatus he helped make understood. Venturi himself died in 1822, long before the device was named for him, so the name honours his research rather than any invention of his own.