Nozzle

About: Nozzle is a research topic. Over the lifetime, 158675 publications have been published within this topic receiving 893026 citations. The topic is also known as: spout.

Convectively cooled, single stage, fully premixed fuel/air combustor for gas turbine engine modules

Abstract: An annular combustor system has an annular housing defining a single stage combustor, an external fuel/air premixer system to provide a preselected, nominally constant lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. Compressed air conduits channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor. Convection cooling of the annular housing and the turbine shroud is accomplished using essentially the remainder portion of the compressed air without diluting the fuel air ratio in the combustion zone. The premixer includes a venturi, and a fuel nozzle for spraying fuel into the venturi inlet along the venturi axis to provide admission of the fully premixed fuel/air mixture. The venturi includes a perforated flow-smoothing and premixing initiating member surrounding both the venturi inlet and the fuel nozzle exit which is spaced from the venturi inlet to prevent impingement of the liquid fuel spray on the venturi walls and augment vaporization of liquid fuels.

A magnetic nozzle calculation of the force on a plasma

Abstract: The measured axial force imparted from a magnetically expanding current-free plasma has been shown recently [Takahashi, Phys. Rev. Lett. 107, 235001 (2011)] to equal the axial force on that plasma calculated by a two-dimensional fluid model. Here, we calculate the same axial force on the plasma by a quasi one-dimensional model of a magnetic nozzle. The quasi one-dimensional magnetic nozzle model provides us with an estimate of the force on the plasma that is similar to that found by the more accurate two-dimensional model.

Exhaust mixing in turbofan aeroengines

Abstract: The core engine of a mixed exhaust turbofan aeroengine is provided with a conical afterbody. The normal outlet guide vanes which remove residual swirl from the turbine exhaust gases are dispensed with and replaced by ducts within an afterbody having entries which receive the hot gases in the same manner and at the same angle as the passages between the guide vanes would have done. The hot ducts, whose aspect ratio is preferably transformed between their upstream and downstream ends, extend through the afterbody in substantially straight paths to avoid aerodynamic losses, and intersect its conical surface to form preferably slot-like nozzles from which the turbine exhaust gases issue as flattened jets. The exhaust jets partake of the original axial and tangential/swirl velocity components of the turbine gases, plus a radial component (consequential upon the orientation of the ducts) to achieve good penetration of the bypass stream. Satisfactory mixing between the bypass stream and the jets is achieved because of the radial and tangential velocity components and because the bypass stream flows in sheets between the jets. No net swirl in the mixed stream through the propulsion nozzle is ensured by counter-swirling of the bypass stream before mixing commences.

A dual fuel nozzle

Abstract: A dual fuel nozzle is provided with two different size injection holes. The first injection holes have larger diameters and are used only for injecting gaseous fuel into a combustion chamber. On the other hand, the second injection nozzles have smaller diameters and are used for injecting either gaseous fuel or liquid fuel as required. When gaseous fuel is used, if the fuel injection amount is large or medium, both of the first and the second injection holes or first injection holes only are used for injecting gaseous fuel depending upon the required fuel injection amount. When the fuel injection amount is low, only the second injection hole is used for injecting gaseous fuel. Therefore, the pressure drop across the fuel nozzle can be kept at sufficiently high level even when the fuel injection amount is low, and thereby combustion vibration is suppressed. Further, when liquid fuel is used, a premixed fuel and steam mixture is injected from the second injection holes. This also keep the pressure drop across the fuel nozzle at high level in order to suppress combustion vibration when the fuel injection amount is low.