Enhanced stress prediction correlation for abdominal aortic aneurysm using fluid structure interaction technique

The rupture of the abdominal aortic aneurysm (AAA) occurs when the acting stress exceeds the ultimate stress of the wall. Therefore, the ability to accurately estimate the acting stress is very useful to predict the rupture of an AAA. In this study, previously developed equation which included the effect of inter lumen thrombus, systolic pressure, maximum aneurysm diameter, wall thickness, asymmetry parameter, is improved by applying fully coupling-fluid structure interaction technique (f-FSI). Further improvements of the equation is also done by including the aneurysm length and iliac bifurcation angle. Various case studies are analyzed to investigate the hemodynamic behavior as well as stress distribution on the wall using modified models as well as Computed Tomography scan (CT scan). The results show that the geometry parameters as well as hypertension affect the flow pattern, displacement and stress distribution. Exponential correlation is observed between the maximum acting stress and the asymmetric parameter. In addition, a linear correlation with the maximum aneurysm, aneurysm length, iliac bifurcation angle and wall thickness is determined. The parametric correlations confirm that these geometry parameters are important parameters to predict the maximum acting stress. The inclusion of the effect of hemodynamic by using f-FSI technique predicted a higher maximum acting stress in AAA wall compared to previous equations. Consequently, the current research has concluded that the newly developed equation can be easily used for rupture prediction with even more accurate results than the currently used clinical tools

Transsient analysis of fluid structure interaction in straight pipe

Water hammer phenomenon is a common problem for flows in pipes. Water hammer usually occurs when transfer of fluid is quickly started, stopped or is forced to make a rapid change in direction. The aim of this study is to use method of characteristics to study water hammer phenomenon. In this study, computational method is used to investigate the transient water hammer problem in a straight pipe. Method of characteristics is applied to constant density flow in a simple reservoir-pipeline-valve system. The water hammer effect is produced via suddenly closing the valve located at the upstream and downstream ends, respectively. Quasi steady shear stress is assumed for the flow. This study also considers steady and unsteady friction. Fluid structure interaction will also be analyzed. The results obtained show slightly higher pressure than that of published experimental data. This could be due to the Quasi steady shear stress assumption. Final results show that when fluid structure interaction is considered, more accurate answers were determined

Proceedings of First Conference for Engineering Sciences and Technology: Vol. 1

This volume contains contributed articles of Track 1, Track 2 & Track 3, presented in the conference CEST-2018, organized by Faculty of Engineering Garaboulli, and Faculty of Engineering, Al-khoms, Elmergib University (Libya) on 25-27 September 2018. Track 1: Communication and Information Technology Track 2: Electrical and Electronics Engineering Track 3: Oil and Chemical Engineering Other articles of Track 4, 5 & 6 have been published in volume 2 of the proceedings at this lin