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

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.

IMPROVING THE DESIGN OF THERMAL TOOLS FOR ROCK FRACTURING

The article deals with the main parameters of the thermodynamic working device for rock destruction due to the implementation of a new method of fuel mixture combustion in shock waves initiated by a high-speed torch burner in gas-dynamic combustion intensifiers. A device for thermal destruction of rocks has been developed, which belongs to the mining industry and can be used for directed impact on rocks when they are destroyed by hot gas jets in mining, stone processing and construction industries. Also, installed coaxial to the nozzle, with increasing inside diameter, a cylindrical nozzle, with two cascades of ejection holes - the first cascade is made at a distance from the Laval nozzle, equal to the distance to complete expansion of the jet of the torch, then, the accelerating section of the nozzle and the new, formed by burning the unburned fuel, jet of the burner. It is found that the cross sectional area of the inner hole of the cylindrical nozzle, is made with an excess of the area of the critical cross section of the nozzle Laval burner 2.5-3 times, in which, because of the rapid expansion of the gas flow in the nozzle, there is turbulization, with the formation of a powerful zone of heating of the gas flow and the appearance of a standing detonation wave in it. The drilling angle of the ejection holes of the first stage is 45-50º to the axis of the nozzle, which serves for ejection of atmospheric air, the oxygen of which reacts with the surplus of combustible in the main jet of the burner and the formation of a more powerful jet.

Substantiation of Parameters of Friction Elements of Bernoulli Grippers With a Cylindrical Nozzle

The article provides a step-by-step justification of the parameters of the friction elements of the Bernoulli gripping devices with a cylindrical nozzle. The effect of friction element parameters on the lifting force of Bernoulli grippers with the classic design of the active surface and with the rounded-off nozzle and flat and toroidal surface is considered. Influence of friction elements location radius on grip lifting force is considered. Influence of friction elements shape on grip lifting force is considered. Effect of friction coefficient between friction elements of grip and object of manipulation on minimum required lifting force in order to perform handling operation is investigated. Influence of number of friction elements on Bernoulli grip lifting force is considered. For the grip design with the rounded-off nose and flat and toroidal surface when the elliptical friction elements overlap the end gap by 73%, the lifting force will increase by 7% in torsion with the lifting force without the friction elements.

Comparative study on a physical model of specific features of top blowing through the tip with folded nozzles when blowing single-phase liquids

The aim of the work was to study the nature and peculiarities of the interaction of the lance of the converter lance flowing from the folded nozzles with a liquid bath of single-phase liquid. The study was conducted on the basis of a physical model of the converter with top purge. The design of a folded nozzle consisting of a central cylindrical nozzle and a slit annular nozzle located around it is investigated. A visual and video recording comparative study in comparable operating conditions of the folded nozzle with different design features, in particular, with an additionally deepened central nozzle in the folded nozzle and a protruding central nozzle; with operation of one cylindrical nozzle, four nozzles of identical section and an annular slot nozzle. It is established that the jet flowing from the folded nozzle differs in the possibility of more active interaction with the liquid bath than one cylindrical nozzle and four nozzles of equivalent plane. The depth of penetration of the jet into the bath liquid, the parameters of the formed hole of the jet penetration, the oscillations of the bath were studied. It is established that the peculiarities of crater formation in the liquid, characteristic when using a folded nozzle, are due to the use of a slotted annular part of the nozzle. The wider crater is due to the use of a slotted annular part of the nozzle. It is shown that the structural variants of the folded nozzle with a recessed or protruding central nozzle do not increase either the depth or the width of the formed crater. It is also established that the peculiarities of crater formation in the liquid when using a folded nozzle are due to the use of a slotted annular part of the nozzle. To form the best purge conditions, the slice of the slotted annular part should be flush with the slice of the central nozzle. With this design, the jet pulse is maintained for a longer period compared to the use of only one central nozzle, probably due to the protection of the central jet, and due to its deep penetration properties.