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viscous-fluids
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Electrohydrodynamic Stability of a Cylindrical Jet under an Axial Electric Field
, M.Sc. Thesis Sharif University of Technology ; Kebriaee, Azadeh (Supervisor) ; Morad, Mohammad Reza (Supervisor)
Abstract
Due to the large application of electro-sprays in various industries, the study of the stability of electro-hydrodynamic flows is important. This thesis examines the stability of cylindrical liquid jets in the presence of an axial electric field. The definition of this jet is a simplified model of electrospray, electrospinning. In this model, the stability of a free incompressible cylindrical flow with surface tensile strength, conductivity, polarization, viscosity, and dielectric constant is determined, irrespective of the solubility of the jet and the surrounding fluid (air), in the presence of uniform axial electric field has taken. This will be done by adding the forces generated by the...
On the Application of Viscous Fluid Dampers in Improving the Seismic Torsional Response of Asymmetric Concrete Buildings Considering the Soil-Structure Interaction
, M.Sc. Thesis Sharif University of Technology ; Rahimzadeh Rofooei, Fayyaz (Supervisor)
Abstract
The feasibility of passive energy dissipation devices such as viscous fluid dampers in controlling the torsional response of structures against seismic loadings has been explored by different researchers in recent years. In the majority of these studies, it is assumed that the structures are located on rigid bases. On the other hand, the effect of Soil-Structure Interaction (SSI) for the structures located on soft soil, on their dynamic parameters and structural responses can be prominent. In this study, the application of viscous fluid dampers in improving the torsional behavior of asymmetric concrete moment resisting frame buildings is investigated, taking into account the soil-structure...
A new correlative model for viscosity estimation of pure components, bitumens, size-asymmetric mixtures and reservoir fluids
, Article Journal of Petroleum Science and Engineering ; Volume 147 , 2016 , Pages 624-635 ; 09204105 (ISSN) ; Jamshidi, S ; Sharif University of Technology
Elsevier B.V
Abstract
Estimation of petroleum fractions properties is one of the major problems in the reservoir fluids analysis, due to the fact that they cannot exactly be diagnosed and their constituents are not available clearly. In this study, a simple model has been developed to estimate the viscosity of pure hydrocarbon substances, bitumens, size-asymmetric mixtures and reservoir fluids (containing unknown hydrocarbon mixtures or petroleum fractions). The proposed model has been extended based on the two conventional and physical properties which can be measured for both pure components and unknown mixtures, without requiring to have their components and compositions. This model uses the pressure (P),...
Evaluation of the Performance of Fluid Dampers in Controlling the Seismic-Induced Response of Structures
, M.Sc. Thesis Sharif University of Technology ; Rahimzadeh Rofooei, Fayaz (Supervisor)
Abstract
Natural disasters, such as earthquakes and hurricanes, can strike without warning, resulting in a range of destruction from structural damage to loss of life. For this reason, research on structural control, which provides a new basis for design of structural systems against winds, earthquakes, waves, and traffic loadings, become of interest in civil engineering. This thesis focuses on using fluid dampers as a passive energy dissipation device. Viscous Fluid Dampers (VFD) are the most commonly used passive energy dissipation devices that are manufactured in various forms. However, the orifice type of Viscous Fluid Damper (VFD) is considered for structural applications. In this thesis, the...
Size-dependent characteristics of electrostatically actuated fluid-conveying carbon nanotubes based on modified couple stress theory
, Article Beilstein Journal of Nanotechnology ; Volume 4, Issue 1 , 2013 , Pages 771-780 ; 21904286 (ISSN) ; Rastgoo, A ; Ahmadian, M. T ; Sharif University of Technology
2013
Abstract
The paper presents the effects of fluid flow on the static and dynamic properties of carbon nanotubes that convey a viscous fluid. The mathematical model is based on the modified couple stress theory. The effects of various fluid parameters and boundary conditions on the pull-in voltages are investigated in detail. The applicability of the proposed system as nanovalves or nanosensors in nanoscale fluidic systems is elaborated. The results confirm that the nanoscale system studied in this paper can be properly applied for these purposes
Buckling and vibration characteristics of a carbon nanotube-reinforced spinning cantilever cylindrical 3D shell conveying viscous fluid flow and carrying spring-mass systems under various temperature distributions
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 233, Issue 13 , 2019 , Pages 4590-4605 ; 09544062 (ISSN) ; Esmailpoor Hajilak, Z ; Habibi, M ; Safarpour, H ; Sharif University of Technology
SAGE Publications Ltd
2019
Abstract
In this article, buckling and vibrational behaviors of a carbon nanotube reinforced spinning cylindrical thick shell carrying spring–mass systems and conveying viscous fluid flow are investigated under various temperature distributions. Also, the installed sensors on the proposed system are considered as a tip mass. The uniform distribution and the functionally graded distribution patterns of reinforcement are considered. The modeled cylindrical thick shell and governing equations are derived by a new three-dimensional refined higher-order theory. Finally, the effects of various types of carbon nanotube reinforcements and other parameters on buckling and vibrational characteristics of the...
Life Cycle Cost-Based Optimal Seismic Design of Steel Buildings with Supplemental Dampers by Utilizing Endurance Time Method
, Ph.D. Dissertation Sharif University of Technology ; Esmaeil Pourestekanchi, Homayoon (Supervisor)
Abstract
This study proposes an efficient risk-targeted framework for integrated optimal seismic design and quantifying target safety of steel Special Moment-Resisting Frames (steel SMRFs) with and without various passive damping devices such as Buckling-Restrained Braces (BRBs), Friction Dampers (FDs), and Fluid Viscous Dampers (FVDs). This framework provides an automated design procedure formulated as a constrained single-objective optimization problem to achieve the minimum Life Cycle Cost (LCC) within the Particle Swarm Optimization (PSO) algorithm and can be the basis of current seismic codes for target safety calibration. LCC includes initial construction cost and lifetime seismic losses such...
The Flexural instability of spinning flexible cylinder partially filled with viscous liquid
, Article Journal of Applied Mechanics, Transactions ASME ; Volume 77, Issue 1 , September , 2010 , Pages 1-9 ; 00218936 (ISSN) ; Haddadpour, H ; Sharif University of Technology
2010
Abstract
This paper deals with the flexural instability of flexible spinning cylinders partially filled with viscous fluid. Using the linearized Navier-Stokes equations for the incompressible flow, a two-dimensional model is developed for fluid motion. The resultant force exerted on the flexible cylinder wall as the result of the fluid motion is calculated as a function of lateral acceleration of the cylinder axis in the Laplace domain. Applying the Hamilton principle, the governing equations of flexural motion of the rotary flexible cylinder mounted on general viscoelastic supports are derived. Then combining the equations describing the fluid force on the flexible cylinder with the structural...
Stabilized Meshless Local Petrov-Galerkin (MLPG) method for incompressible viscous fluid flows
, Article CMES - Computer Modeling in Engineering and Sciences ; Volume 29, Issue 2 , 2008 , Pages 75-94 ; 15261492 (ISSN) ; Sharif University of Technology
2008
Abstract
In this paper, the truly Meshless Local Petrov-Galerkin (MLPG) method is extended for computation of steady incompressible flows, governed by the Navier-Stokes equations (NSE), in vorticity-stream function formulation. The present method is a truly meshless method based on only a number of randomly located nodes. The formulation is based on two equations including stream function Poisson equation and vorticity advection-dispersion-reaction equation (ADRE). The meshless method is based on a local weighted residual method with the Heaviside step function and quartic spline as the test functions respectively over a local subdomain. Radial basis functions (RBF) interpolation is employed in shape...