Papers by Keyword: Pressure

Abstract: A bridge die was designed for the simultaneous extrusion of two rectangular profiles and used in a strictly monitored aluminum extrusion process. Experimental investigations aimed at the measurement of the mandrel deflection, the local die temperature, and the pressure inside the welding chamber by means of special measurement equipment. AA6082 alloy was used as extrusion material. The influence of the extrusion speed on the aforementioned objectives is reported. The experiments were repeated at least three times under the same conditions in order to achieve a statistical validation of the acquired data. These data are provided as reference for the 2013 edition of the Extrusion Benchmark.

Abstract: The article deals with the newly developed damp proofing systems. They are aimed at principles of the design of constructional details of substructures resisting water and ground dampness with application of the latest materials, technology and constructional design of damp proofing system layers and details.

Abstract: The porous aerostatic conveyor bearings are used to feed large substrates such as the flat panel display glass sheets and the silicon wafers by supporting them with compressed air in a non-contact condition. Due to unevenly distributed pressure in the air film between the substrate and the porous aerostatic conveyor bearing, the soft substrate often deforms and tilts on the bearing pad during the feeding process. In order to investigate the pressure distribution in the air gap, the CFD software, FLUENT, was employed to simulate the operation of the porous aerostatic conveyor bearing during the feeding process. In addition, the load capacity of the conveyor air bearing was calculated. The results show there is low vacuum pressure around the air discharge holes. The high pressure above the air supply holes forms two paraboloidal distributions in the air film. For design modification, the air supply and the air discharge holes need to be rearranged and/or relocated to improve the pressure distribution in the air film for more stable feeding of the substrate.

Abstract: The phenomenon of direct-contact condensation gains attention because of various industrial applications; nuclear reactor emergency core cooling systems,steam driven jet injectors, direct-contact heat exchangers etc..The phenomenon was investigated computationally by injecting an inclined steam jet using a supersonic nozzle submerged in subcooled water. The condensation mechanism is based on two resistance model, which involves consideration of the heat transfer process on both sides of the interface along with use of a variable steam bubble diameter. For computations, ANSYS Fluent based Euler-Euler multiphase model is used. The angle of inclination varies from 5^o to 45^o at constant inlet pressure of 7 bars with water temperature of 30°C. The maximum penetration length is achieved using a right angled vertical injection.

Abstract: Oxyacetylene flame heights which were obtained through representation from a number of camera shots were compared from those estimated from empirical correlations for determining the flame height based on the heat release rate (Q) and flame base diameter (D). Pressure of gas mixtures are purposely changed to obtained a varying flow rate with the flame set to neutral during each routine. It is found that operating conditions like Reynolds number and flow rate influences the profile of the combustion flame.

Abstract: The measuring system of the tester is consisted of the downhole measuring tester and ground replaying system, structure and parameters of the tester has been designed, of the testing circuit

Abstract: The paper aims to highlight the pressure and velocity variations on power lines created by water flowing through a cylindrical valve. Drain valve is typical cylindrical bottom of the dam or hydroelectric penstocks. Varieties of dimensions of these valves allow different analyses of the dynamics within them. The valves are able to access water from both sides and different ways of filling and closing action items. This paper presents a method to analyse the influence of parameters on physical-mechanical construction or operation and hence derive dynamic optimal design of these types of valves. Refer to the more intermediate positions of the piston sealing and visualization power lines and areas of turbulence for each position.

Abstract: Coolant for gundrill under MQL is impermissible to be high pressure, large quantity, or direct emission on the interface. These restricts would be seriously unfavorable to lubrication. Experiments reveal that poor lubricating always appear on the hole periphery with dark burns on the hole wall. A prospective solution is to regulate the pressure distribution by modifying the dub-off structure. Its derivation is detailed in this paper. Its validity is demonstrated by practical experiments.

Abstract: Pneumatic splice makes use of high-speed compressed air as the driving force to complete the yarn splicing, noticing that the change of the vent pressure has a significant effect on yarn splicing. This paper studies the impact of vent pressure on the quality of yarn splicing when twisting and untwisting. Modeling, analysis and simulation of the air splice is done with the integration of Pro/E and ANSYS software, to study the flow filed and obtain the influence on the speed and pressure of the inside the splicing chamber when changing the speed and pressure while keeping the diameter of splicing chamber diameter, the vent hole diameter and the relative angle are unchanged. The results of the analysis of the air splice will lay a solid foundation for the further optimized structure design.

Abstract: Optical fiber sensors have been used widely in offshore oilfield. An optical fiber sensor system including an optical fiber sensor testing temperature and pressure under well, a connector connecting the optical fiber sensor with the optical cable, two connectors connecting cables, 3600 meters armoured optical cable and an interrogator was applied in an offshore oil well on Zhoushan island. The temperature and pressure under well have been measured for about two month and the testing results are presented in this paper.