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.

Effect of Inner Nozzle Lip Thickness on Co-flow Jet Characteristics

This paper presents the experimental results of subsonic and underexpanded sonic jets delivered from a central nozzle surrounded by a co-flow. The role of central nozzle lip thickness on the co-flow jet characteristics has been studied. The jet-mixing enhancement is achieved in the case of jet from the thick-lip nozzle compared to that of thin-lip nozzle. The extent of supersonic zone for the thick-lip is much shorter than the thin-lip jet.

Stability Of An Ellipsoidal Head With A Central Nozzle Under Axial Load

The subject of the numerical investigation is an ellipsoidal head with a central (axis-symmetrical) nozzle. The nozzle is loaded by axial load force. The ellipsoidal head is under axial-symmetrical compression load. The numerical FEM model is elaborated. The calculation will provide the critical loads and equilibrium paths for the sample head.. The investigation will measure the influence of the diameter of the nozzle on the critical state of the ellipsoidal head.

Effect of Co-Flow on Near Field Shock Structure

This paper presents the experimental results of underexpanded jets delivered from a central nozzle surrounded by a co-flow. The co-flow is found to be effective in elongating the supersonic core length of the central jet, at all levels of underexpansion. However, the expansion level of the central jet dictates the elongation caused by the co-flow.

Swirling Flow in a Fixed Container: Generation and Attenuation of a Vortex Column

The development of a columnar vortex and its attenuation using radial rods at the bottom boundary of a stationary container are experimentally studied. The fluid motion is achieved combining two independent flows: a global circulation around the cylinder axis and a meridian flow generated by recirculating fluid through a central nozzle located at the vessel bottom. The resulting velocity field is analyzed under two conditions: with and without the meridian or suction flow. It is shown that in the second condition a columnar vortex merges and that its intensity increases when the suction flow rate is increased. The key role played by the bottom boundary layer in the vortex formation is demonstrated. In the last part of the work, the attenuation of the vortex intensity produced by a set of rods located at the vessel bottom is investigated. It is found that obstacles with heights of the order of the boundary layer thickness are enough to produce the total annihilation of the vortex column.

DISCRETE PARTICLE SIMULATION OF FLOW PATTERNS IN TWO-DIMENSIONAL GAS FLUIDIZED BEDS

The flow patterns in two-dimensional gas fluidized bed were simulated numerically by the Distinct Element Method, Gas is issued through the entire width of the base with uniform velocity. Several flow patterns, such as slugging and bubbling, are observed in the results. As the gas flow rate increases, the flow pattern changes from slugging to bubbling. It is confirmed that particle mixing is promoted by bubbling. The flow pattern of bubbling is irregular in comparison with the case of gas injection through a central nozzle which was simulated in our previous study.

Bent Jets in Radio Quasars

How is energy transported out from the central engine in quasars and radio galaxies to the distant radio lobes? This problem has been around since the early discovery of classical double radio sources, and is still not answered in detail. The idea of relativistic beams was first suggested by Martin Rees as a means of transporting plasma out of the nucleus (Rees, 1971, Blandford and Rees, 1974). This idea gained support first from the discovery of hot spots in the radio lobes of these large classical double sources, and later by observations of the beams themselves in radio galaxies. As more jets were observed, it became obvious that they were often curved, serpentine, or even sharply bent. This behavior has been modeled as precession of the central nozzle (Bridle et al., 1976, Ekers et al., 1978), as nuclear refraction (Henriksen et al., 1981), as a growing plasma instability (Hardee, 1981) and as various combinations of the above. At the present time, it seems safest to conclude that there are some examples of each of these processes known.

Background of New Code Rules for Integral Flat Heads with a Large, Central Nozzle

Paragraph UG-39 (c) of ASME Section VIII, Division 1, 1980 Edition states: “Flat heads that have an opening with a diameter that exceeds one-half of the head diameter or shortest span, as defined in UG-34, shall be designed as a flange in accordance with the Rules for Bolted Flange Connections given in Appendix 2.” The application of Appendix 2 to such configurations is subject to various interpretations, accordingly, rules have been written for the specific case of a single, large central opening (nozzle) in integral flat heads. The new rules will appear in the Winter 1980 Addenda; for configurations not provided for the designer is referred to U-2 (g).