Effects of nozzle geometry on kinetics in free-jet expansions

The flame used in combustion flame spraying is typical of a high-temperature free jet. The flow fields of free jets are multi-phase flows that couple the mass and heat transfer. The analytical and numerical solutions to turbulent flows are engineering approximations. This work uses Prandtle’s mixing-length theory to describe the flame spreading of free combustion spray jet and uses nozzle spray model to describe the distribution of the powder particles sprayed from powder nozzle to the substrate surface. The nozzle geometry and the parameters determine the distribution of the powder particles. The nozzle spray model has the same physical meaning with the jet spreading angle. Experimental measurements were carried by a high-speed CCD camera.

Download Full-text

Effect of nozzle geometry and semi-confinement on the potential core of a turbulent axisymmetric free jet

International Communications in Heat and Mass Transfer ◽

10.1016/0735-1933(96)00001-2 ◽

1996 ◽

Vol 23 (2) ◽

pp. 155-162 ◽

Cited By ~ 62

Author(s):

S. Ashforth-Frost ◽

K. Jambunathan

Keyword(s):

Nozzle Geometry ◽

Potential Core ◽

Free Jet

Download Full-text

Needle-Free Jet Injectors’ Geometry Design and Drug Diffusion Process Analysis

Applied Bionics and Biomechanics ◽

10.1155/2021/5199278 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Yunfei Wang ◽

Long Yue ◽

Lechuan Hu ◽

Jing Wang

Keyword(s):

Diffusion Process ◽

Process Analysis ◽

Subcutaneous Tissue ◽

Nozzle Geometry ◽

Drug Diffusion ◽

Free Jet ◽

Cylindrical Nozzle ◽

Geometry Design ◽

Nozzle Geometries ◽

Jet Injectors

In order to study the injection and diffusion process of the drug in the subcutaneous tissue of a needle-free jet injectors (NFJIs) in detail and understand the influence of different nozzle geometry on the diffusion process of the drug, in this paper, numerical simulations were performed to study the diffusion process of the drug in the subcutaneous tissue of NFJIs with cylindrical nozzle. On this basis, the differences of the drug diffusion process with different nozzle geometries were analyzed. The results show that the drug diffused in the shape of ellipsoid in the subcutaneous tissue. The penetration of the drug into the subcutaneous tissue is deeper under the condition of conical nozzle and conical cylindrical nozzle at the same time. However, it takes longer to spread to the interface between skin and subcutaneous tissue in reverse.

Download Full-text

Influence of nozzle geometry on underexpanded axisymmetric free jet characteristics

Shock Waves ◽

10.1007/s00193-012-0391-x ◽

2012 ◽

Vol 22 (5) ◽

pp. 427-434 ◽

Cited By ~ 12

Author(s):

K. Hatanaka ◽

T. Saito

Keyword(s):

Nozzle Geometry ◽

Free Jet ◽

Jet Characteristics

Download Full-text

Production and STEM examination of controlled-size silver clusters

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075488 ◽

1983 ◽

Vol 41 ◽

pp. 338-339

Author(s):

M. A. Listvan ◽

R. P. Andres

Keyword(s):

Cluster Size ◽

Metal Clusters ◽

Experimental Parameter ◽

Carbon Films ◽

Metal Species ◽

Silver Clusters ◽

Free Jet ◽

Size Dependent ◽

Cluster Properties ◽

Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Download Full-text