Patent ID: 8215116

Claim:
A system, comprising: a fuel nozzle, comprising: a tubular body portion with an inlet end portion and an outlet end portion; a nozzle base portion having a tapered central body coaxial with the tubular body portion, wherein the nozzle base portion is disposed adjacent the inlet end portion of the tubular body portion, wherein an annular flow region is disposed between the tubular body portion and the tapered central body, wherein the tapered central body comprises an upstream end portion, a downstream end portion, an outer surface facing outwardly toward an inner surface of the tubular body portion between the upstream and downstream end portions, and a plurality of fuel ports disposed along the outer surface about a longitudinal axis of the fuel nozzle, wherein downstream corresponds to a direction of fluid flow from the inlet end portion toward the outlet end portion of the tubular body portion; a radial air swirler coaxial with the tubular body portion, wherein the radial air swirler extends about the tapered central body, and the radial air swirler is disposed between the tubular body portion and nozzle base portion; and a converging diverging venturi chamber coaxial with and located inside the tubular body portion, wherein the converging diverging venturi chamber has a generally smooth curved surface, the converging diverging venturi chamber comprises a diverging section having a diverging angle and a converging section having a converging angle, the diverging angle does not exceed about 15 degrees along substantially an entire diverging length of the diverging section, the converging angle does not exceed about 30 degrees along substantially an entire converging length of the converging section, an entrance into the converging section is downstream of the radial air swirler, an exit from the diverging section extends toward the outlet end portion of the tubular body portion, and the radial air swirler has a first outer diameter that is less than or substantially equal to a second outer diameter of the inlet end portion of the tubular body portion.