A Comparative Study on Laminar Flow of Multiple Orifice Gases through a Tubular Welding Electrode

Abstract

For an attempt to design a recently developed environmentally friendly manual welding process, that is aimed at reducing/eliminating the use of cellulose in its flux coating, a tubular coated welding electrode with a gas passes through the orifice of the tube is necessary. The objective of this study is to investigate and understand the flow characteristics of such intended orifice gasses that are to flow through the electrode tube. An attempt was made to simulate the flow of three different gasses such, argon, helium and carbon dioxide by using a commercial finite element tool with volumetric flow, mean velocity and pressure head as input parameters. A specially made mild steel coated electrode tube with an inner diameter of 1.8 mm was considered for the study. An axisymmetric mode was generated based on the tubular welding electrode dimension with inlet,pipe wall,center line and outlet as boundary regions.The model was simulated with optimum mesh grid size on axial and radial distance of the axisymmetric model. From the result obtained the fluid flow characteristic such as laminar,transition and turbulent were found at selected volume flow rate ranges. The characteristic of fluid flow regions and the relationship of entrance length, pressure variation and maximum velocity at fully developed region were obtained. The simulated results were compared and validated with analytical solutions for the accuracy.