Thermodynamic models of gas mixtures for computational fluid dynamics

An approach is considered that allows to obtain a thermodynamic model of a gas mixture when the thermodynamic properties of its components are given. Models of interpenetrating and mutually displacing components are considered. The model of interpenetrating components was tested on the basis of comparing the properties of air and a mixture of gases corresponding to air by its composition. As an example of hydrodynamic modelling using a model of interpenetrating components, the electromagnetic compression of an array of mixed composition (metal and polymer) was computed. The modelling results are in slightly better agreement with the experimental data than previous computations using the dominant component model.

Effect of Variable Tube Wall Thicknesses of Al-Mg-Si Alloy Tube During Electromagnetic Compression using Four Turn Axi-Symmetric Coil

Electromagnetic compression (EMC) is a solid state, high velocity process of deformation of materials. In this process the enhancement of the formability is achieved due to high strain rate forming. In the present study Aluminum alloy AA6061 tube has been compressed using four turn axisymmetric coil. The effect of variable tube wall thicknesses i.e. 1.0, 1.7, and 2.4 mm during the compression of the Al-Mg-Si Aluminum alloy tube electromagnetically has been studied. A constant gap between coil inner diameter (ID) and workpiece outer diameter (OD) was maintained. It has been found that the tube deformation was maximum when the wall thickness was minimum. For compression, 8 kJ energy was used with double power bank. A three dimensional (3D) model of four turn compression coil has been proposed using LS-DYNA software. Comparison between the numerical simulation and experimental results showed a close agreement between both the results. Compression using EMF process can be used in modern industries like automotive, aerospace and nuclear power plants.

Joining of Tubular Parts by Electromagnetic Forming: Computational Investigations of Strength

A frequent application of electromagnetic forming in the industry is joining by electromagnetic compression of tubular parts. The goodness of the joints is determined by the strength of the joint, and it is considered excellent if it reaches the strength of the weaker material pair. Strength of these joint are generally tested for tensile and torsion loadings. In order to increase strength, one or more horizontal and/or radial grooves can be fabricated onto the male joining pair to utilize form fitting besides interference fit. In the present paper, the strength of the joint is studied by finite element simulations.

Electromagnetic Tube Compression: A Novel Experimental Technique and Finite Element Simulation

The dynamic electromagnetic compression technique of metal tube which can be used for study of collapse with cylindrical symmetry like the thick-walled cylinder (TWC) technique is introduced. 3D simulations by multiphysics ANSYS finite element code are used for metal tube compression, and the magnetic flux density, displacement, and strain in process are obtained. The influence of the sizes of the tube is considered in the tube compression. The finite element analysis results show that the specimen which has small height or thinner thickness is easier to compress than the big one. The study can offer valuable information about the process analysis of metal tube electromagnetic compression and specimen design.