This paper describes results of a factorial experiment on coal cutting at a traverse speed of 5 meters/min, with water jets at pressures between 500 and 2,000 atmospheres and nozzle diameters in the range from 0.5 to 1 mm. These results fill a gap in the existing results on coal cutting with water jets and form the basis for the design of a coal cutting machine. The interrelationship between pr...

A high-resolution stereoscopic particle image velocimetry (PIV) system was used to conduct three-dimensional measurement of an air jet exhausted from a lobed nozzle. The characteristics of the mixing process in the lobed jet  ow are revealed clearly and quantitatively from the stereoscopic PIV measurement results. The instantaneous velocity and streamwise vorticity distributions revealed that ...

Background: The aim was to unravel how the air-polishing behaves on a titanium surface by evaluating the size and the shape of the cleaned area, influence of the different device settings, and pocket depths and cleaning movements. Methods: 48 titanium SLA surface film-coated discs were treated with an air abrasive system using a subgingival plastic nozzle. Two subgingival models were employed: ...

We designed a specially designed coaxial spinneret in this study. The inner stainless-steel needle was connected to the inner plastic syringe just like the traditional one. The outer stainless-steel needle was replaced by a plastic nozzle, and connected to the outer plastic syringe. The tip of the inner stainless-steel needle was shortened 2 cm from the tip of the outer plastic nozzle. This str...

Article history: Received: 09.06.2015. Received in revised form: 01.10.2015. Accepted: 08.10.2015. Liquid nitrogen is expected to be used as a jet medium in petroleum engineering because of its cryogenic and non-polluting characteristics. To identify the velocity distribution characteristics of liquid nitrogen jet, a computational fluid dynamics model was built by coupling the equations for nit...

Experiments measuring the single-cycle impulse from detonation tubes with nozzles were conducted by hanging the tubes in a ballistic pendulum arrangement within a large tank. The detonation-tube nozzle and surrounding tank were initiallyfilledwith air between 1.4 and 100kPa in pressure simulating high-altitude conditions.A stoichiometric ethylene–oxygen mixture at an initial pressure of 80 kPa ...

Over the last ten years, robustness of schemes has raised an increasing interest among the CFD community. The objective of this article is to solve the quasi-one-dimensional compressible flow inside a “Shubin nozzle” and to investigate Bean-Warming and flux vector splitting methods for numerical solution of compressible flows. Two different conditions have been considered: first, there is a sup...

In this research mass transfer coefficient under jetting regime in different directions (from dispersed to continuous and continuous to dispersed phase) has been studied using an experimental setup. n-Butanol-succinic acid-water with low interfacial tension has been selected as experimental chemical system. The effects of various parameters such as jet velocity, nozzle diameter and the heig...

In view of the uneven artificial sowing, low sowing, as well as the fact that the existing seeders cannot meet the sowing requirements of Pteris vittata, this paper designed an automatic plug seeder by using the method of spraying and sowing after mixing spores and water. In order to obtain the optimum working parameters of the seeder, response surface method (RSM) was employed to desi...

An experimental and numerical analysis of a low-angle annular expander nozzle is presented to observe the variance in shock structure within the flow field. A RANS-based axisymmetric numerical model was used to evaluate flow characteristics and the model validated using experimental pressure readings and schlieren images. Results were compared with an equivalent convergingdiverging nozzle to de...