Jet Impingement Angle Research Articles

Impingement of Rectangular Jets on a Ground Plane

THE azimuthal distributions of wall jet radial momentum flux have been experimentally determined for the impingement of turbulent jets emanating from rectangular nozzles with exit area aspect ratios between one and eight. Data are presented for parametric variations in nozzle exit height above ground, nozzle pressure ratio, and jet impingement angle caused by rotation of the nozzle about the nozzle exit major and minor axes. The momentum flux distributions were found to be highly directional and sensitive to variations in the above parameters.

The dependence of the Geometry of glassy alloy ribbons on the chill block melt-spinning process parameters

Metallic ribbons were formed under a wide variety of chill block melt-spinning process conditions for several glass-forming alloy systems. An analysis of ribbon geometry data was used to establish simple empirical equations which relate ribbon width and thickness to process parameters such as the volumetric material flow rate, the substrate surface speed, the melt jet diameter and the melt jet impingement angle. Ribbon geometry data from other researchers are generally found to conform well to the relations established in the present work. Processing factors in addition to those discussed in detail, such as melt superheat and alloying additions, are discussed with regard to their effect on ribbon geometry.

Flow of liquid jets through closely woven screens

Previously developed analytical models relate pressure drop across a fine-mesh screen to throughflow velocity for duct systems. These models are shown to be unreliable for an unconfined flow, such as a free jet, impinging on a screen. A new model is developed for these kinds of systems, incorporating the important influence of liquid deflection by the screen. A new parameter, the boundary-layer blockage coefficient, is introduced. This coefficient, which depends on the screen weave geometry and the jet impingement angle, accounts for the increase in fluid path length through the screen resulting from the flow deflection. Comparisons are made with previous experimental studies to determine empirical values of the blockage coefficient. It is concluded that the new model reliably predicts the bulk flow and penetration characteristics of an impinging liquid jet interacting with a screen.

Wetting delay due to film and transition boiling on hot surfaces

The time to achieve wetting of hot rods in air by a hot water jet was found to be a very strong function of water subcooling, and a strong function of jet velocity, surface thermal conductivity, heat generation rate, jet impact angle and surface temperature. Surface finish and rod size had little effect. The results agree with a simple model considering forced convection film boiling, heat generation and heat conduction from the surrounding surface.