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.

Simulation of Noise Generation in Near-Nozzle Region of a Chevron Nozzle Jet

Abstract: This paper reports on the simulation of the near-nozzle region of a moderate Reynolds number cold jet flow exhaustingfrom achevron nozzle.Thechevron nozzleconsideredinthis studyisthe SMC001nozzleexperimentally studied by researchers at the NASA John H. Glenn Research Center. This nozzle design contains six symmetric chevrons that have a 5-deg penetration angle. The flow inside the chevron nozzle and the free jet flow outside are computed simultaneously by a high-order accurate, multiblock, large-eddy simulation code with overset grid capability.Theresolutionofthesimulationisabout100milliongridpoints.Themainemphasisofthesimulationisto capture the enhanced shear-layer mixing due to the chevrons and the consequent noise generation that occurs in the mixing layers of the jet within the first few diameters downstream of the nozzle exit. Details of the computational methodology are presented together with an analysis of the simulation results. The simulation data are compared with available experimental measurements of the flowfield and the noise spectrum in the sideline direction. Overall, thesimulationresultsareveryencouraginganddemonstratethefeasibilityofchevronnozzlejetcomputationsusing our simulation methodology. Nomenclature c

A Converging Slot-Hole Film-Cooling Geometry—Part 2: Transonic Nozzle Guide Vane Heat Transfer and Loss

Abstract: This paper presents the first experimental measurements on an engine representative nozzle guide vane, of a new film-cooling hole geometry, a convergingslot-hole or console. The patented console geometry is designed to improve the heat transfer and aerodynamic performance of turbine vane and rotor blade cooling systems. These experiments follow the successful validation of the console design in low-speed flat-plate tests described in Part 1 of this paper. Stereolithography was used to manufacture a resin model of a transonic, engine representative nozzle guide vane in which seven rows of previously tested fan-shaped film-cooling holes were replaced by four rows of consoles. This vane was mounted in the annular vane ring of the Oxford cold heat transfer tunnel for testing at engine Reynolds numbers, Mach numbers and coolant to mainstream momentum flux ratios using a heavy gas to simulate the correct coolant to mainstream density ratio. Heat transfer data were measured using wide-band thermochromic liquid crystals and a modified analysis technique. Both surface heat transfer coefficient and the adiabatic cooling effectiveness were derived from computer-video records of hue changes during the transient tunnel run. The cooling performance, quantified by the heat flux at engine temperature levels, of the console vane compares favourably with that of the previously tested vane with fan-shaped holes. The new console film-cooling hole geometry offers advantages to the engine designer due to a superior aerodynamic efficiency over the fan-shaped hole geometry. These efficiency measurements are demonstrated by results from midspan traverses of a four-hole pyramid probe downstream of the nozzle guide vane.

Thermally actuated ink jet printing mechanism having a series of thermal actuator units

Abstract: An inkjet nozzle arrangement includes a nozzle chamber having an fluid ejection nozzle in one surface of the chamber; a paddle vane located within the chamber, the paddle vane being adapted to be actuated by an actuator device for the ejection of fluid out of the chamber via the fluid ejection nozzle; and a thermal actuator device located externally of the nozzle chamber and attached to the paddle vane the thermal actuator device including a plurality of separate spaced apart elongated thermal actuator units. The thermal actuator units are constructed from multiple layers utilizing a single mask to etch the multiple layers.

Ink-jet head

Abstract: PURPOSE:To make it possible to certainly remove air bubbles in a nozzle, by integrally forming a supply pipe for supplying ink to the nozzle and the nozzle as an almost linear glass tube while arranging said tube on a carriage in such a state that the leading end of said tube for injecting ink droplets is inclined to an upward direction CONSTITUTION:A carriage 7' almost simillar to a carriage 7 is attached to a yoke 6 in a freely slidable manner and the upper surface thereof is inclined downwardly toward a rear part thereof so as to correspond to the bottom surface shape of the holder 9' of an ink jet head mounted thereon That is, the bottom surface of the holder 9' is inclined toward the rear part thereof and a nozzle 22 having a piezoelectric element 11 mounted thereto is arranged in the holder 9' along the bottom surface thereof The nozzle 22 is formed into an almost linear hollow cylindrical shape which is throttled into an almost cone shape at the leading end part thereof and has an ink jet orifice 22a formed to the leading end thereof as well as formed of glass as a whole and has an elongated lenth as a whole Because the nozzle 22 is linearly formed and arranged so as to upwardly incline the leading end thereof, air bubbles are moved to an upward direction by its buoyancy even if present in the nozzle 22 and discharged to the open air from the jet orifice 22a and automatically removed