Abstract: A flow device and method delivers a gaseous medium to utilization equipment having variable pressure conditions at its intake. A gaseous medium intake zone connects with structure defining a variable area throat zone for constricting the flow of the gaseous medium to increase the velocity thereof to sonic. The throat zone is adjustably varied in correlation with operating demands imposed upon the utilization equipment. Wall structure downstream from the throat zone provides a gradually diverging zone for efficiently recovering the kinetic energy of the high velocity gaseous medium as static pressure. Through such efficient recovery the velocity of gaseous medium through the throat zone is sonic over a wide range of pressure conditions at the intake of the utilization equipment. A flow splitter is spaced from the adjustable throat zone and the splitter is arranged to divide the downstream end portion of gradually diverging zone into multiple zones of reduced divergence.

Abstract: A combustible air-liquid fuel mixture having a substantially constant air-to-fuel ratio is produced for delivery to the intake manifold of an engine. Air is passed through a fluid flow device having a variable area throat zone to increase the velocity of the air to sonic, and the area of the throat zone is varied in correlation with operating demands imposed upon the engine for which the mixture is produced. Liquid fuel is metered from a supply into the air stream at or before the throat zone in direct proportion to the cross-sectional area of the throat zone. The pressure of the high velocity air stream is sensed at a point where it bears a predictable relationship to atmospheric pressure, and the rate of fuel delivered into the air stream is adjusted in response to changes in the air pressure sensed so that the air-to-fuel ratio of the mixture is maintained substantially constant.