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amirkhosravi--mehrad
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Effect of Stenotic Carotid Geometry on Flow and Stroke-risk
, M.Sc. Thesis Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; Saeedi, Saeed (Supervisor)
Abstract
Carotid bifurcation is one of the most important bifurcations in human body which has a lot of curvature in some people. The common carotid artery bifurcates into an internal carotid artery (ICA) and an external carotid artery (ECA). The incidence of stenosis in carotid bifurcation and in particular in the internal carotid artery is of special importance. In the United States of America by 2006, nearly 700000 strokes occur each year, with about 160000 deaths and 20 to 30% of strokes are caused by stenotic carotid that cost estimated at $160 billion. The purpose of this thesis is to investigate in hemodynamic factors of blood flow such as velocity variation, vortex patterns, shear stress and...
Three dimensional heat transfer modeling of gas-solid flow in a pipe under various inclination angles
, Article Powder Technology ; Vol. 262, Issue. 1 , 2014 , pp. 223-232 ; ISSN: 0032-5910 ; Saffar Avval, M ; Mansoori, Z ; Amirkhosravi, M ; Sharif University of Technology
2014
Abstract
The turbulent heat transfer in gas-solid flows through an inclined pipe under various inclination angles is studied with constant wall heat flux. The hydrodynamic k- τ and kθ- τθ thermal two phase model is used in a lagrangian/Eulerian four way approach. The numerical results agreed reasonably with available experimental data in vertical and horizontal pipe flows. The effects of inclination angles on the flow patterns are reported. The pressure drop and Nusselt number are enhanced significantly as the inclination increases up to a certain angle. The mass loading ratio has influence on the optimal inclination angle. With increasing loading ratio, the optimal inclination angle of maximum...
Multidimensional modeling of the stenosed carotid artery: A novel CAD approach accompanied by an extensive lumped model
, Article Acta Mechanica Sinica/Lixue Xuebao ; Vol. 30, issue. 2 , 2014 , p. 259-273 ; Mahdinia, M ; Firoozabadi, B ; Amirkhosravi, M ; Ahmadi, G ; Saidi, M. S ; Sharif University of Technology
2014
Abstract
This study describes a multidimensional 3D/lumped parameter (LP) model which contains appropriate inflow/outflow boundary conditions in order to model the entire human arterial trees. A new extensive LP model of the entire arterial network (48 arteries) was developed including the effect of vessel diameter tapering and the parameterization of resistance, conductor and inductor variables. A computer aided-design (CAD) algorithm was proposed to efficiently handle the coupling of two or more 3D models with the LP model, and substantially lessen the coupling processing time. Realistic boundary conditions and Navier-Stokes equations in healthy and stenosed models of carotid artery bifurcation...
Adaptive neuro-fuzzy algorithm applied to predict and control multi-phase flow rates through wellhead chokes
, Article Flow Measurement and Instrumentation ; Volume 76 , 2020 ; Wood, D. A ; Mohamadian, N ; Rashidi, S ; Davoodi, S ; Soleimanian, A ; Kiani Shahvand, A ; Mehrad, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
A Takagi-Sugeno adaptive neuro-fuzzy inference system (TSFIS) model is developed and applied to a dataset of wellhead flow-test data for the Resalat oil field located offshore southern Iran, the objective is to assist in the prediction and control of multi-phase flow rates of oil and gas through the wellhead chokes. For this purpose, 182 test data points (Appendix 1) related to the Resalat field are evaluated. In order to predict production flow rate (QL) expressed as stock-tank barrels per day (STB/D), this dataset includes four selected input variables: upstream pressure (Pwh); wellhead choke sizes (D64); gas to liquid ratio (GLR); and, base solids and water including some water-soluble...
A geomechanical approach to casing collapse prediction in oil and gas wells aided by machine learning
, Article Journal of Petroleum Science and Engineering ; Volume 196 , 2021 ; 09204105 (ISSN) ; Ghorbani, H ; Wood, D. A ; Mehrad, M ; Davoodi, S ; Rashidi, S ; Soleimanian, A ; Shahvand, A. K ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The casing-collapse hazard is one that drilling engineers seek to mitigate with careful well design and operating procedures. However, certain rock formations and their fluid pressure and stress conditions are more prone to casing-collapse risks than others. The Gachsaran Formation in south west Iran, is one such formation, central to oil and gas resource exploration and development in the Zagros region and consisting of complex alternations of anhydrite, marl and salt. The casing-collapse incidents in this formation have resulted over decades in substantial lost production and remedial costs to mitigate the issues surrounding wells with failed casing string. High and vertically-varying...